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You are here: Home / Publications / Bibliographies and Resource Guides / Information Resources on Reptiles   / Reproduction  Printer Friendly Page
Information Resources on Reptiles
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Al Dokhi, O.A. (2006). Ultrastructure of sperm head differentiation in the lizard, Acanthodactylus boskinus (Squamata, Reptilia). International Journal of Zoological Research 2(1): 60-72. ISSN: 1811-9786.
NAL Call Number: QL1.I584
Descriptors: reptiles, Acanthodactylus boskinus, lizard, sperm head, ultrastructural, differentiation, golgi phase, maturation phase.

Al Dokhi, O.A. and S.H. Al Wasel (2002). Ultrastructure of spermiogenesis in the freshwater turtle Mauremys caspica (Chelonia, Reptilia). III: the sperm tail formation. Journal of Union of Arab Biologists Cairo A Zoology 18: 327-341. ISSN: 1110-5372.
Descriptors: reptiles, freshwater turtle, Mauremys caspica, spermiogenesis, sperm tail formation, ultrastructure, Arabia.
Language of Text: Arabic; English.

Al Habsi, A.A., A.Y.A. Alkindi, I.Y. Mahmoud, D.W. Owens, T. Khan, and A. Al Abri (2006). Plasma hormone levels in the green turtles Chelonia mydas during peak period of nesting at Ras Al-Hadd-Oman. Journal of Endocrinology 191(1): 9-14. ISSN: 0022-0795.
NAL Call Number: 448.8 J8293
Descriptors: reptiles, green turtles, nesting, peak period, plasma hormone levels, estradiol, progesterone, testosterone, corticosterone.

Alberts, A.C., N.C. Pratt Hawkes and J.A. Phillips (2003). Ontogeny of captive and wild iguanas: From emergence to mating. In: E.R. Jacobson Biology, Husbandry, and Medicine of the Green Iguana, Krieger Publishing Company: Malabar, USA, p. 28-37. ISBN: 1575240653.
Descriptors: reptiles, green iguana, captive and wild animals, ontogeny, emergence, mating behavior.

Alkindi, A.Y., I.Y. Mahmoud, M.J. Woller, and J.L. Plude (2006). Oviductal morphology in relation to hormonal levels in the snapping turtle, Chelydra serpentina. Tissue and Cell 38(1): 19-33. ISSN: 0040-8166.
Abstract: Microscopic and in situ visual observations were used to relate circulating hormone levels to morphological changes in the oviduct of the snapping turtle Chelydra serpentina throughout the ovarian cycle. Increase in levels of progesterone (P), estradiol (E2) and testosterone (T) levels coincide with an increase in number and growth of endometrial glands, luminal epithelial cells and secretory droplets throughout the oviduct. Testosterone and estradiol levels rose significantly (P < 0.05) after the May-June period and remained high throughout the rest of the summer. Progesterone levels remained stable throughout the summer, with a brief decline in July due to luteolysis. Hormonal values declined significantly (P < 0.001) at the end of the ovarian cycle in the fall. In situ visual observation of fresh oviducts at different stages of gravidity in recently ovulated turtles revealed that proteinaceous like components from the endometrial glands were released into the lumen to form fibers. The morphological features of the oviduct remained active throughout the summer months even though the snapping turtle is a monoclutch species which deposits all the eggs in late-May to mid-June. The high steroid levels correlate with and may be responsible for the secretory activity present throughout the summer and their decline correlates with change to low secretory activity in the fall. Calcium deposition accompanied by morphological changes in luminal cells are suggestive of secretory activity. In the egg-bearing turtles, uterine Ca2+ concentrations measured by flame atomic absorption spectrophotometry revealed significantly higher Ca2+ concentrations (P < 0.001) in eggs with soft shell than eggs without shell. There was a significant increase in calcium granules and proteinaceous fibers in luminal surface of the uterus during the period of eggshelling. This supports the fact that in the snapping turtle like in other reptiles, eggshelling process occurs in the uterus.
Descriptors: snapping turtle, Chelydra serpentina, estradiol blood, oviducts anatomy, histology, progesterone, testosterone, turtles anatomy, histology, calcium analysis, egg shell physiology, oviducts cytology, physiology, ovum chemistry, physiology, reproduction, seasons, turtles blood, physiology, uterus anatomy, histology, chemistry, vagina anatomy, histology.

Allsop, D.J., D.A. Warner, T. Langkilde, W. DU, and R. Shine (2006). Do operational sex ratios influence sex allocation in viviparous lizards with temperature-dependent sex determination? Journal of Evolutionary Biology 19(4): 1175-1182. ISSN: 1010-062X.
Abstract: Under certain environmental situations, selection may favour the ability of females to adjust the sex ratio of their offspring. Two recent studies have suggested that viviparous scincid lizards can modify the sex ratio of the offspring they produce in response to the operational sex ratio (OSR). Both of the species in question belong to genera that have also recently been shown to exhibit temperature-dependent sex determination (TSD). Here we test whether pregnant montane water skinks (Eulamprus tympanum) utilise TSD to select offspring sex in response to population wide imbalances in the OSR, by means of active thermoregulation. We use a combination of laboratory and field-based experiments, and conduct the first field-based test of this hypothesis by maintaining females in outdoor enclosures of varying OSR treatments throughout pregnancy. Although maternal body temperature during pregnancy was influenced by OSR, the variation in temperature was not great enough to affect litter sex ratios or any other phenotypic traits of the offspring.
Descriptors: lizards physiology, sex determination analysis, sex ratio, temperature, viviparity, nonmammalian.

Aranha, I., M. Bhagya, H.N. Yajurvedi, and B.K. Sagar (2004). Light microscopical and ultrastructural studies on the vas deferens of the lizard Mabuya carinata. Journal of Submicroscopic Cytology and Pathology 36(3-4): 247-256. ISSN: 1122-9497.
Abstract: Adult male lizards (Mabuya carinata) were studied during breeding and non breeding seasons to determine the regional and seasonal differences if any in the vas deferens and to compare ultrastructural features of luminal epithelial cells with those of endotherms. The vas deferens of the lizard is a convoluted tube extending from the epididymis to the hemipenis passing over the kidney. Based on morphometric data of luminal diameter and epithelial cell height three distinct regions viz; proximal, middle and distal regions were identified in the vas deferens. The epithelium is surrounded by a thin layer of lamina propria, many layers of circular smooth muscle fibers and an outer layer of visceral pleuro peritoneum. Based on cell and nuclear morphology and ultrastructure, five different cell types viz; principal cell, basal cell, mitochondria rich cell, halo cell and narrow cell were identified in the epithelium during both breeding and non breeding season. Principal cells and basal cells were more abundant in both seasons. The types of luminal epithelial cells of vas deferens of M. carinata and their ultrastructural features are similar to those of mammals. Further, vas deferens of M. carinata differs from mammals in having only circular smooth muscles in contrast to circular and longitudinal muscles of mammalian vas deferens. To the best of our knowledge this is the first report describing cell types of vas deferens, their ultrastructure and ultrastructural seasonal variations in reptiles.
Descriptors: reptiles, lizards, anatomy, histology, vas deferens, ultrastructure, epididymis anatomy, epithelial cells ultrastructure, muscle, smooth, ultrastructure.

Belaid, B., H.N. Cong, G. Devilliers, N. Richard Mercier, C. Pieau, and M. Dorizzi (2004). Lymphoid aggregates in gonads of embryos, hatchlings, and young of turtles with temperature-dependent sex determination. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 301(2): 160-168. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Descriptors: turtles, gonads cytology, temperature, physiology, lymphocytes ultrastructure, electron microscopy, sex differentiation, anatomy, histology, turtles embryology.

Blackburn, D.G., A.R. Johnson, and J.L. Petzold (2003). Placental ultrastructure in the brown snake Storeria dekayi. SICB Annual Meeting and Exhibition Final Program and Abstracts 2003: 118. ISSN: print: 1540-7063; online: 1557-7023.
Descriptors: reptiles, brown snake, placental ultrastructure, meeting abstracts.
Notes: Meeting Information: Annual Meeting and Exhibition of the SICB (Society for Integrative and Comparative Biology), Toronto, ON, Canada; January 04-08, 2003.

Blackburn, D.G. and R.L. Lorenz (2003). Placentation in garter snakes. II. Transmission EM of the chorioallantoic placenta of Thamnophis radix and T. sirtalis. Journal of Morphology 256(2): 171-186. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, garter snakes, placentation, transmission EM, chorioallantoic placenta, ultrastructure, allantoplacenta.

Blackburn, D.G. and R.L. Lorenz (2003). Placentation in garter snakes. III. Transmission EM of the omphalallantoic placenta of Thamnophis radix and T. sirtalis. Journal of Morphology 256(2): 187-204. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, garter snakes, placentation, transmission EM, omphalallantoic placenta.

Blackburn, D.G., J.R. Stewart, D.C. Baxter, and L.H. Hoffman (2002). Placentation in garter snakes: scanning EM of the placental membranes of Thamnophis ordinoides and T. sirtalis. Journal of Morphology 252(3): 263-275. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, garter snakes, placentation, EM scanning, placental membranes, cross sections, uterine epithelium.

Broderick, A.C., F. Glen, B.J. Godley, and G.C. Hays (2003). Variation in reproductive output of marine turtles. Journal of Experimental Marine Biology and Ecology 288(1): 95-109. ISSN: 0022-0981.
NAL Call Number: QH91.A1J6
Descriptors: reptiles, marine turtles, reproductive output, variation, eggs laid per clutch, clutches per season, effects of environmental conditions.

Calderon, M.L., G.R. de Perez, and M.P. Ramirez Pinilla (2004). Morphology of the ovary of Caiman crocodilus (Crocodylia: Alligatoridae). Annals of Anatomy 186(1): 13-24. ISSN: 0940-9602.
Descriptors: reptiles, Caiman crocodilus, ovary, morphology, reproduction.

Carvalho, R.C., A.L. Sousa, C.E.B. Moura, T.N. Faria, W.P. Costa, H.R.A. Resende, H.M. Pereira, and A.N.B. Mariana (2003). Morfologia do penis do jabuti de patas vermelhas (Geochelone carbonaria Spix, 1824). [Morphology of the penis of the red-footed tortoise (Geochelone carbonaria Spix, 1824)]. Revista Brasileira De Reproducao Animal 27(2): 229-230. ISSN: 0102-0803.
NAL Call Number: QP251.R48
Descriptors: reptiles, Geochelone carbonaria, anatomy, penis, reproduction, red footed tortoise, morphology, conference information.
Language of Text: Portuguese; Summary in English.
Notes: Meeting Information: XV Congresso Brasileiro de Repoducao Animal, Porto Seguro, Bahia, Brazil, 11-15 August 2003.

Centini, R. (2005). Reproductive husbandry and problems of snakes. Proceedings of the Annual Conference of the Association of Reptilian and Amphibian Veterinarians 12: 37-39. ISSN: 1529-9651.
NAL Call Number: SF996.A77
Descriptors: reptiles, reproductive husbandry, problems, captivity, snakes, conference proceedings.

Chen, Q.S., L. Zhang, X.W. Chen, and X.K. Han (2006). Ultrastructure of spermatozoon in soft-shelled turtle Trionyx sinensis. Acta Zoologica Sinica 52(2): 415-423. ISSN: 0001-7302.
Descriptors: reptiles, soft shelled turtle, Trionyx sinensis, spermatazoon, ultrastructure.
Language of Text: Chinese; Summary in English.

Colli, G.R., R.D. Teixeira, D.M. Scheltinga, D.O. Mesquita, H.C. Wiederhecker, and S.N. Bao (2007). Comparative study of sperm ultrastructure of five species of teiid lizards (Teiidae, Squamata), and Cercosaura ocellata (Gymnophthalmidae, Squamata). Tissue and Cell 39(1): 59-78. ISSN: 0040-8166.
Abstract: Sperm ultrastructure of five teiid lizards (Callopistes flavipunctatus, Crocodilurus amazonicus, Dicrodon guttulatum, Dracaena guianensis, and Teius oculatus), and the gymnophthalmid Cercosaura ocellata is described for the first time. Comparisons of sperm ultrastructure among these species and with those of previously examined teiids and gymnophthalmids revealed that the two groups of Teiioidea (Gymnophthalmidae and Teiidae), and the two subfamilies of Teiidae (Teiinae and Tupinambinae) could be distinguished on the basis of sperm ultrastructure data. Significant differences in sperm dimensions between Cnemidophorus and Aspidoscelis support the recent splitting of these two lineages into different genera. Our results revealed high levels of inter-generic variability in sperm ultrastructure within Teiidae, which produces a data set useful in analyzing relationships between genera and families. In phylogenetic analyses, however, sampling multiple species within teiid genera is essential and recording sperm measurements may profitably complement qualitative ultrastructural characters, maximizing the information content of these structures.
Descriptors: reptiles, teiid lizards, sperm ultrastructure, comparative study, sperm dimensions, differences, inter-generic variability.

Cox, R.M. and H.B. John Alder (2005). Testosterone has opposite effects on male growth in lizards (Sceloporus spp.) with opposite patterns of sexual size dimorphism. Journal of Experimental Biology. 208(Pt 24): 4679-4687. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Sexual size dimorphism (SSD) has received considerable attention from evolutionary biologists, but relatively little is known about the physiological mechanisms underlying sex differences in growth that lead to SSD. Testosterone (T) stimulates growth in many male-larger vertebrates, but inhibits growth in the female-larger lizard Sceloporus undulatus. Thus, opposite patterns of SSD may develop in part because of underlying differences in the hormonal regulation of male growth. In the present study, we examined the effects of T on male growth in two sympatric congeners with opposite patterns of SSD (S. virgatus: female-larger; S. jarrovii: male-larger). During the mating season, yearling males of both species have higher plasma T levels than females, but whereas yearling males of S. virgatus grow only half as fast as females, yearling males of S. jarrovii grow more quickly than females. Thus, we hypothesized that T inhibits growth in yearling S. virgatus males, but promotes growth in yearling S. jarrovii males. In support of this hypothesis, we found that castrated (CAST) males of S. virgatus grew faster than castrated males given T implants (TEST). In contrast, TEST males of S. jarrovii grew faster than CAST males. Our results provide the first direct evidence for opposite effects of T on male growth in closely related species with opposite patterns of SSD. We speculate that growth inhibition by T reflects an energetic trade-off between growth and reproductive investment, and propose that such ;costs' of male reproduction may help explain the evolution of female-larger SSD in Sceloporus.
Descriptors: lizards, Sceloporus spp., evolution, growth, development, drug effects, sex characteristics, testosterone, pharmacology, orchiectomy, species specificity, testosterone blood.

Cree, A., C.L. Tyrrell, M.R. Preest, D. Thorburn, and L.J. Guillette (2003). Protecting embryos from stress: corticosterone effects and the corticosterone response to capture and confinement during pregnancy in a live-bearing lizard (Hoplodactylus maculatus). General and Comparative Endocrinology 134(3): 316-329. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Hormones in the embryonic environment, including those of the hypothalamo-pituitary-adrenal (HPA) axis, have profound effects on development in eutherian mammals. However, little is known about their effects in reptiles that have independently evolved viviparity. We investigated whether exogenous corticosterone affected embryonic development in the viviparous gecko Hoplodactylus maculatus, and whether pregnant geckos have a corticosterone response to capture and confinement that is suppressed relative to that in non-pregnant (vitellogenic) females and males. Corticosterone implants (5 mg, slow-release) administered to females in mid-pregnancy caused a large elevation of corticosterone in maternal plasma (P<0.001), probable reductions in embryonic growth and development (P=0.069-0.073), developmental abnormalities and eventual abortions. Cool temperature produced similar reductions in embryonic growth and development (P< or =0.036 cf. warm controls), but pregnancies were eventually successful. Despite the potentially harmful effects of elevated plasma corticosterone, pregnant females did not suppress their corticosterone response to capture and confinement relative to vitellogenic females, and both groups of females had higher responses than males. Future research should address whether lower maternal doses of corticosterone produce non-lethal effects on development that could contribute to phenotypic plasticity. Corticosterone implants also led to increased basking in pregnant females (P<0.001), and basal corticosterone in wild geckos (independent of reproductive condition) was positively correlated with body temperature (P<0.001). Interactions between temperature and corticosterone may have broad significance to other terrestrial ectotherms, and body temperature should be considered as a variable influencing plasma corticosterone concentrations in all future studies on reptiles.
Descriptors: reptiles, lizard, gecko, embryo stress, protecting, corticosterone, effects, response, capture, confinement, pregnancy.

Custodia Lora, N. and I.P. Callard (2002). Progesterone and progesterone receptors in reptiles. General and Comparative Endocrinology 127(1): 1-7. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: The role of progesterone (P) has been most extensively studied in the female reproductive tissues (ovary, reproductive tract, mammary gland) and in the brain, in which it is an important regulator and modulator in conjunction with estradiol (E). In nonmammalian vertebrate species, less work has been done on P metabolites involved in ovulation. In addition, P induces the expression of egg-white proteins, decreases myometrial contractility, and facilitates processing of eggs, formation of eggshell, and deposition of egg-white proteins. Actions of P may be synergistic with, or antagonist to, the actions of E, depending on hormone ratios, timing of exposure, and physiological state. These effects of P are mediated through progesterone receptor isoform A (PRA), a general transcription inhibitor of P target genes, and isoform B (PRB), a specific transcriptional stimulator of some reproductive tract genes. In this review, we focus on P action and PR expression in the liver and reproductive tissues of several reptilian species, especially Chelonia, since most of the data obtained are from this group. We also present novel data showing the expression of PR in nonreproductive tissues (such as kidney, spleen, gastrointestinal tract) in the painted turtle, Chrysemys picta.
Descriptors: reptiles, painted turtle, Chrysemys picta, progesterone, progesterone receptors, ovary, reproductive tract, brain, reproductive tissues.

Custodia Lora, N., A. Novillo, and I.P. Callard (2004). Regulation of hepatic progesterone and estrogen receptors in the female turtle, Chrysemys picta: relationship to vitellogenesis. General and Comparative Endocrinology 136(2): 232-240. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Previous studies using the fresh water turtle Chrysemys picta have demonstrated the differential expression of the two progesterone receptor isoforms (PRA and PRB) in the liver during the turtle seasonal cycle, correlating with ER mRNA levels and hepatic vitellogenesis. During the inter-vitellogenic periods the ratio of PRB:PRA favors PRA, suggesting that the PRB:PRA ratio may be important in the regulation of vitellogenesis. Based on these and other studies we hypothesize that progesterone may have differential effects on the estrogen (E)-induced vitellogenin response (inhibitory or stimulatory), depending on the PRB:PRA ratio. In this study, we determined the expression pattern and the hormonal regulation of progesterone receptor (PR) isoforms in the liver, during the estrogen-induced vitellogenin response in female C. picta. Northern blot analysis was used to evaluate the changes in vitellogenin mRNA, estrogen receptor (ER) mRNA, and PR mRNA expression; Western blot to determine changes in PR isoform expression and a homologous ELISA for measurement of plasma vitellogenin. The expression of PR isoforms in the liver of female turtles at the mRNA and protein levels was differentially regulated by estradiol and progesterone. Estradiol treatment enhanced the transcription of PR mRNA isoforms and possibly translation and/or increased stability of PRB protein in the female turtle liver. In contrast, this hormone decreased PRA protein levels. Progesterone alone down-regulated progesterone receptor isoform A (PRA) and progesterone receptor isoform B (PRB) proteins equally, but did not affect PR mRNA levels. Estradiol markedly increased hepatic ER mRNA, vtg mRNA, and vtg in plasma, but this effect was not impacted significantly by progesterone. The results presented here indicate that in female turtles hepatic PRB:PRA ratios are markedly changed by estradiol treatment due primarily to a decrease in PRA. The change in the PRB:PRA ratio after hormonal treatment confirms that progesterone and estrogen exposure will be a determinant in the regulation of vitellogenesis, and, in turn, that the regulation of vitellogenesis will be determined by the ratio of PR isoforms and the physiological levels of steroid hormones.
Descriptors: reptiles, female painted turtle, hepatic progesterone, estrogen receptors, regulation, vitellogenesis.

de Solla, S.R., P.A. Martin, K.J. Fernie, B.J. Park, and G. Mayne (2006). Effects of environmentally relevant concentrations of atrazine on gonadal development of snapping turtles (Chelydra serpentina). Environmental Toxicology and Chemistry 25(2): 520-526. ISSN: 0730-7268.
NAL Call Number: QH545.A1E58
Abstract: The herbicide atrazine has been suspected of affecting sexual development by inducing aromatase, resulting in the increased conversion of androgens to estrogens. We used snapping turtles (Chelydra serpentina), a species in which sex is dependent on the production of estrogen through aromatase activity in a temperature-dependent manner, to investigate if environmentally relevant exposures to atrazine affected gonadal development. Eggs were incubated in soil to which atrazine was applied at a typical field application rate (3.1 L/ha), 10-fold this rate (31 L/ha), and a control rate (no atrazine) for the duration of embryonic development. The incubation temperature (25 degrees C) was selected to produce only males. Although some males with testicular oocytes and females were produced in the atrazine-treated groups (3.3-3.7%) but not in the control group, no statistical differences were found among treatments. Furthermore, snapping turtle eggs collected from natural nests in a corn field were incubated at the pivotal temperature (27.5 degrees C) at which both males and females normally would be produced, and some males had oocytes in the testes (15.4%). The presence of low numbers of males with oocytes may be a natural phenomenon, and we have limited evidence to suggest that the presence of normal males with oocytes may represent a feminizing effect of atrazine. Histological examination of the thyroid gland revealed no effect on thyroid morphology.
Descriptors: turtles, atrazine toxicity, turtles growth, herbicides toxicity, oocytes growth and development, testis growth and development, turtles growth and development, aromatase biosynthesis, environmental exposure, enzyme induction, estrogens physiology, oocytes drug effects, ovum, temperature, testis cytology, testis drug effects.

Deeming, D.C. and G.F. Birchard (2007). Allometry of egg and hatchling mass in birds and reptiles: roles of developmental maturity, eggshell structure and phylogeny. Journal of Zoology 271(1): 78-87. ISSN: 0952-8369.
Abstract: The factors determining hatchling mass (HM) are investigated in a wide range of birds and reptiles using regression analysis, analysis of covariance and comparative analysis by independent contrasts. In birds, initial egg mass (IEM) at laying is the most important factor affecting HM and phylogenetic relatedness has no significant effects on HM. Developmental maturity of the avian neonates did not affect the proportion of IEM converted into HM. For all reptile species, IEM also significantly affected HM but phylogenetic relatedness did not. By contrast, allometric relationships between IEM and HM in the different orders of reptiles were affected by shell type. The robustness of allometric relationships across taxa in birds and reptiles suggests that there is a physiological link between IEM and HM, which contrasts with that observed for the relationship between egg mass and incubation period. This result has significant implications for the inter-relationships between IEM and embryonic growth, which are discussed for birds and reptiles.
Descriptors: reptiles, birds, egg hatchling mass, allometry, developmental maturity, eggshell structure, phylogeny.

DeNardo, D.F. (2004). Essentials of reproductive physiology for the reptile practitioner. Small Animal and Exotics Book Two: Pain Management Zoonosis Proceedings of the North American Veterinary Conference, Volume 18 18: 1333-1334. ISSN: 0341-6593.
Descriptors: reptiles, reproductive physiology, essentials, reptile practitioner, conference proceedings, book chapter.

Derby, A. (2005). Elevage et reproduction en captivite du Cinosterne odorant, Sternotherus odoratus. [Rearing and captive reproduction of the musk turtle Sternotherus odoratus.]. Manouria 8(26): 6-9. ISSN: 1422-4542.
Descriptors: reptiles, musk turtle, Sternotherus odoratus, rearing, captive reproduction.
Language of Text: French.

Doddamani, L.S. (2006). Differentiation and development of testis in the oviparous lizard, Calotes versicolor (Daud.). Journal of Experimental Zoology Part A Comparative Experimental Biology 305A(3): 299-308. ISSN: 1548-8969.
NAL Call Number: QL1.J854
Descriptors: reptiles, oviparous lizard, testis, development, differentiation, Calotes versicolor.

Du, W.G. and X. Ji (2002). Effects of incubation temperature on duration of incubation. Hatching success, and hatching traits in the gray rat snake, Ptyas korros (Colubridae). Acta Ecologica Sinica 22(4): 548-553. ISSN: 1000-0933.
Descriptors: reptiles, gray rat snake, Ptyas korros, incubation temperature, duration of incubation, hatching success.
Language of Text: Chinese; Summary in Chinese and English.

Eizaguirre, C., D. Laloi, M. Massot, M. Richard, P. Federici, and J. Clobert (2007). Condition dependence of reproductive strategy and the benefits of polyandry in a viviparous lizard. Proceedings of the Royal Society of London. Series B, Biological Sciences 274(1608): 425-430. ISSN: print: 0962-8452; online: 1471-2945.
Abstract: Species in which males do not contribute to reproduction beyond the provision of sperm offer good opportunities to study the potential genetic benefits that females can obtain from polyandry. Here, we report the results of a study examining the relationships between polyandry and components of female fitness in the common lizard (Lacerta vivipara). We found that polyandrous females produce larger clutches than monandrous females. Polyandrous females also lose fewer offspring during the later stages of gestation and at birth, but we did not find any relationship between polyandry and physical characteristics of viable neonates. Our results were consistent with the predictions of the intrinsic male quality hypothesis, while inbreeding avoidance and genetic incompatibility avoidance might also explain some part of the variation observed in clutch size. Moreover, the benefits of polyandry appeared to depend on female characteristics, as revealed by an interaction between reproductive strategy and female length on reproductive success. Thus, all females did not benefit equally from mating with multiple males, which could explain why polyandry and monandry coexist.
Descriptors: reptiles, viviparous lizard, reproductive strategy, polyandry, potential genetic benefits, female fitness, clutch size.

Elf, P.K. (2003). Yolk steroid hormones and sex determination in reptiles with TSD. General and Comparative Endocrinology 132(3): 349-355. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: In reptiles with temperature-dependent sex determination (TSD), the temperature at which the eggs are incubated determines the sex of the offspring. The molecular switch responsible for determining sex in these species has not yet been elucidated. We have examined the dynamics of yolk steroid hormones during embryonic development in the snapping turtle, Chelydra serpentina, and the alligator, Alligator mississippiensis, and have found that yolk estradiol (E(2)) responds differentially to incubation temperature in both of these reptiles. Based upon recently reported roles for E(2) in modulation of steroidogenic factor 1, a transcription factor known to be significant in the sex differentiation process, we hypothesize that yolk E(2) is a link between temperature and the gene expression pathway responsible for sex determination and differentiation in at least some of these species. Here we review the evidence that supports our hypothesis.
Descriptors: reptiles, snapping turtle, alligator, sex determination, incubation temperature, yolk steroid hormones, dynamics, embryonic development.

Elf, P.K., J.W. Lang, and A.J. Fivizzani (2002). Dynamics of yolk steroid hormones during development in a reptile with temperature-dependent sex determination. General and Comparative Endocrinology 127(1): 34-39. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Many oviparous reptiles exhibit temperature-dependent sex determination (TSD); i.e., the temperature at which the egg is incubated determines the sex of the offspring. In TSD reptiles, yolk steroids not only may influence sex determination, but also may mediate hormonal effects on subsequent growth and behavior, as in some avian species. We investigated changes in the levels of estradiol (E(2)) and testosterone (T) during development in yolks of snapping turtle eggs, examined how incubation temperature affects hormone levels, and determined how hormones in turtle eggs are influenced by individual females (=clutch effects). Results indicate significant decreases in both hormones (>50% decline) by the end of the sex-determining period, when two-thirds of the development is complete. The declines in both E(2) and T were significantly affected by incubation temperature, but in different ways. Eggs incubated at female-producing temperatures maintained high levels, those incubated at male-producing temperatures had low E(2) values, and eggs incubated at pivotal temperatures had intermediate levels of E(2). At all three temperatures, T values underwent significant but approximately equal declines, except during the developmental stages just after the sex-determining period, when T levels decreased more at the male-producing temperature than at either of the other two temperatures. Initially, there were significant clutch effects in both hormones, but such differences, attributable to individual females, were maintained only for E(2) later in development. Here we report for the first time that incubation temperature significantly affects the hormonal environment of the developing embryo of a turtle with temperature-dependent sex determination. Based on this and related findings, we propose that yolk sex steroids influence sexual differentiation in these TSD species and play a role in sex determination at pivotal temperatures.
Descriptors: reptiles, snapping turtle, egg yolk steroid hormones, sex determination, temperature dependent, development, incubation, testosterone analysis, turtle embryology.

Ezaz, T., N. Valenzuela, F. Grutzner, I. Miura, A. Georges, R.L. Burke, and J.A. Graves (2006). An XX/XY sex microchromosome system in a freshwater turtle, Chelodina longicollis (Testudines: Chelidae) with genetic sex determination. Chromosome Research 14(2): 139-150. ISSN: print: 0967-3849; online: 1573-6849.
NAL Call Number: QH600.C47
Abstract: Heteromorphic sex chromosomes are rare in turtles, having been described in only four species. Like many turtle species, the Australian freshwater turtle Chelodina longicollis has genetic sex determination, but no distinguishable (heteromorphic) sex chromosomes were identified in a previous karyotyping study. We used comparative genomic hybridization (CGH) to show that C. longicollis has an XX/XY system of chromosomal sex determination, involving a pair of microchromosomes. C-banding and reverse fluorescent staining also distinguished microchromosomes with different banding patterns in males and females in approximately 70% cells examined. GTG-banding did not reveal any heteromorphic chromosomes, and no replication asynchrony on the X or Y microchromosomes was observed using replication banding. We conclude that there is a very small sequence difference between X and Y chromosomes in this species, a difference that is consistently detectable only by high-resolution molecular cytogenetic techniques, such as CGH. This is the first time a pair of microchromosomes has been identified as the sex chromosomes in a turtle species.
Descriptors: fresh water turtle, Chelodina longicollis, sex chromosomes genetics, sex determination genetics, turtles genetics, chromosome banding, karyotyping, nucleic acid hybridization, sex differentiation, staining and labeling.

Fahrig, B.M., M.A. Mitchell, B.E. Eilts, and D.L. Paccamonti (2007). Characterization and cooled storage of semen from corn snakes (Elaphe guttata). Journal of Zoo and Wildlife Medicine 38(1): 7-12. ISSN: 1042-7260.
Abstract: The phylogenetic order Squamata has many representatives that could benefit from the use of semen preservation as a tool for assisting conservation. To date, few studies have been made evaluating the potential for collecting and preserving semen from snakes. The objectives of this study were to characterize semen parameters of the corn snake (Elaphe guttata), including appearance, volume, concentration, sperm motility, and sperm morphology, and to determine the longevity of corn snake sperm motility stored at 4 degrees C. Single semen samples were collected from 22 adult corn snakes. The appearance of the corn snake semen was generally cloudy, and the color was white to tan. Corn snake spermatozoa initially exhibited a median motility of 92.5%. Corn snakes were found to produce small-volume ejaculates (median 0.01 ml). However, the overall concentration of the snake ejaculate was high (chi = 852 x 10(6) +/- 585 x 10(6) spermatozoa/ml). Morphologically, a mean of 75.7 +/- 9.3% of the sperm cells in an ejaculate were normal. Snake ejaculate with a white appearance had significantly higher sperm concentrations (chi = 1,859 x 10(6) +/- 1,008 x 106 sperm cells/ml; F = 15.74, P = 0.001) than tan ejaculates (chi = 601 x 10(6) +/- 439 x 106 sperm cells/ml). Sperm motility decreased significantly in samples that were stored at 4 degrees C for greater than 48 hr in a refrigerator or Equitainer I. This is the first study to characterize semen volume, appearance, and concentration; sperm motility; and sperm morphology in captive corn snakes. The information derived from this study can be used to develop a model for a collection, cooled storage, and shipping program for semen from endangered or threatened captive and wild snakes.
Descriptors: reptiles, corn snakes, Elaphe guttata, cooled storage semen, characterization, semen preservation, sperm morphology, shipping, conservation.

Ferreira, A. and H. Dolder (2003). Sperm ultrastructure and spermatogenesis in the lizard, Tropidurus itambere. Biocell 27(3): 353-362. ISSN: 0327-9545.
Abstract: Spermatogenesis, with emphasis on spermiogenesis, is described for the lizard, Tropidurus itambere, using light microscopy, phase contrast and epifluorescence, as well as scanning and transmission electron microscopy. Cellular differentiation involves events of chromatin condensation, nuclear elongation and the formation of structural complexes, such as the acrosomal and axonemal ones. Other new characteristics, exclusive for this species, include various aspects of the subacrosomal granule, the insertion of the pro-acrosomal vesicle and the development of these structures to participate in the acrosomal complex. Radial projections occurjust above the nuclear shoulders, which have been recognized already from the beginning of cellular elongation. The development of the midpiece, the dense bodies, formation of the flagellum and elimination of residual cytoplasm result in the final characterization of the mature spermatozoon. Comparisons between Tropiduridae and other lizard families are made.
Descriptors: reptiles, lizard, Tropidurus itambere, sperm ultrastructure, spermatogenesis.

Ferreira, A. and H. Dolder (2002). Ultrastructural analysis of spermiogenesis in Iguana iguana (Reptilia: Sauria: Iguanidae). European Journal of Morphology 40(2): 89-99. ISSN: print: 0924-3860; online: 1744-4241.
Abstract: Spermiogenesis in the lizard, Iguana iguana, was studied by transmission and scanning electron microscopy. During this process, structures such as the acrosomal complex in the spermatid head and the axonemal complex in the mid and principal pieces of the flagellum are formed. The nuclear content is initially compacted into thick, longitudinal chromatin filaments. Nuclear shape is determined by further compaction and by the manchette, a layer of microtubules surrounding the head. The acrosomal complex originates from Golgi vesicles and the interaction between the proacrosomal vesicle and the nucleus. The midpiece consists of a pair of centrioles, surrounded by a fibrous sheath and rings of simple and modified mitochondria. The centrioles sustain the axoneme that appears at the end of the midpiece. The axoneme extends throughout the principal piece of the flagellum with the 9 + 2 pattern, still surrounded by the fibrous sheath. In the endpiece, the axoneme continues, surrounded only by the plasma membrane. In the lumen of seminiferous tubules, immature spermatozoa retain abundant residual cytoplasm.
Descriptors: reptiles, Iguana, spermiogenesis, ultrastructureal analysis, scanning electron microscopy.

Gaibazzi, G. (2005). Elevage et reproduction de la platemyde de l'Amazone, Batrachemys raniceps (Gray, 1855). [Rearing and reproduction of the turtle Batrachemys raniceps (Gray, 1855).]. Manouria 8(27): 27-32. ISSN: 1422-4542.
Descriptors: reptiles, turtle, Batrachemys raniceps, reproduction, captive breeding, rearing.
Language of Text: French.

Gal, J., M. Mandoki, E. Sos, and M. Marosan (2004). Tojasvisszatartas es kovetkezmenyes savos-fibrines savoshartya-gyulladas vitorlas agama (Hydrosaurus amboinensis) testuregeben. [Egg retention and consequent catarrhal-fibrinoid inflammation of serous membrane in a sailfin lizard's (Hydrosaurus amboinensis) abdominal cavity]. Magyar Allatorvosok Lapja 126(5): 290-292. ISSN: 0025-004X.
Descriptors: reptiles, sailfin lizard, Hydrosaurus amboinensis, egg retention, reproductive disorders, serous membrane, inflammation, abdominal cavity.
Language of Text: Hungarian; Summary in English.

Ganesh, C.B. and H.N. Yajurvedi (2002). Stress inhibits seasonal and FSH-induced ovarian recrudescence in the lizard, Mabuya carinata. Journal of Experimental Zoology. 292(7): 640-648. ISSN: print: 0022-104X; online: 1097-010X.
NAL Call Number: 410 J825
Descriptors: reptiles, lizard, Mabuya carinata, stress, inhibits, FSH induced, ovarian recrudescence.

Gao, Z.f. (2005). Observation on behavior and reproduction of some reptiles under artificial breeding condition. Sichuan Journal of Zoology 24(2): 180. ISSN: 1000-7083.
Descriptors: reptiles, reproduction, observation, artificial breeding condition, behavior.
Language of Text: Chinese.

Gartrell, B.D., J.E. Girling, A. Edwards, and S.M. Jones (2002). Comparison of noninvasive methods for the evaluation of female reproductive condition in a large viviparous lizard, Tiliqua nigrolutea. Zoo Biology 21(3): 253-268. ISSN: 0733-3188.
NAL Call Number: QL77.5.Z6
Descriptors: reptiles, viviparous lizards, Tiliqua nigrolutea, zoo animals, gestation period, ovulation, radiography, ultrasonography, ovarian follicles, accuracy, pregnancy diagnosis, females, palpation, ultrasonic diagnosis, ultrasonic devices, diagnostic value.

Gilland, E.H. and A.C. Burke (2004). Gastrulation in reptiles. In: C.D. Stern (Editor), Gastrulation: From Cells to Embryo, Cold Spring Harbor Laboratory Press.: Cold Spring Harbor, NY, p. 205-217. ISBN: 0879697075.
NAL Call Number: QL955 .G34 2004
Descriptors: reptiles, gastrulation, cells, embryo.

Girling, J.E., S.M. Jones, and R. Swain (2002). Delayed ovulation and parturition in a viviparous alpine lizard (Niveoscincus microlepidotus): morphological data and plasma steroid concentrations. Reproduction, Fertility, and Development 14(1-2): 43-53. ISSN: 1031-3613.
NAL Call Number: QP251.R47
Abstract: The southern snow skink, Niveoscincus microlepidotus, exhibits an unusual biennial reproductive cycle with an extended gestation period of approximately 1 year. Morphological data were gathered on a monthly basis, providing a detailed picture of the reproductive cycle. Vitellogenesis begins in spring, immediately after parturition. Maximum follicular diameter is reached before the winter hibernation period and ovulation occurs the following spring. Embryos are fully developed and reach maximum size by early autumn. Yolk reserves are depleted before winter. Birth of between one and four young occurs the following spring. Plasma progesterone concentrations are low (2.7 +/- 0.9 ng mL(-1)) in post-partum females, begin to rise in autumn in vitellogenic females and peak (38.5 +/- 7.9 ng mL(-1)) in pre-ovulatory females after hibernation. Concentrations are high (15.4 +/- 5.9 ng mL(-1)) in early pregnancy and decline to basal levels before winter and well before birth in spring. Plasma oestradiol concentrations peak during vitellogenesis (1.0 +/- 0.3 ng mL(-1)) and decline to basal levels during pregnancy (0.2 +/- 0.03 ng mL(-1)). A second oestradiol peak occurs before parturition (0.7 +/- 0.2 ng mL(-1)). Thus, functional completion of vitellogenesis and gestation is achieved by autumn in successive years. The mechanisms that defer ovulation and parturition by a further six months are unknown.
Descriptors: reptiles, snow skink, Niveoscincus microlepidotus, delayed ovulation, parturition, alpine lizard, Niveoscincus microlepidotus, plasma steroid concentrations, reproductive cycle.

Girondot, M., P. Rivalan, R. Wongsopawiro, J.P. Briane, V. Hulin, S. Caut, E. Guirlet, and M.H. Godfrey (2006). Phenology of marine turtle nesting revealed by statistical model of the nesting season. BMC Ecology 6: 11. ISSN: 1472-6785.
Descriptors: reptiles, marine turtle, nesting, phenology, statistical model, nesting season, eggs, mathematical model.

Gist, D.H., S. Bradshaw, C.M. Morrow, J.D. Congdon, and R.A. Hess (2007). Estrogen response system in the reproductive tract of the male turtle: an immunocytochemical study. General and Comparative Endocrinology 151(1): 27-33. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Portions of the reproductive tract of the male (Trachemys scripta) turtle were examined by immunocytochemistry for evidence of the capacity to produce and respond to estrogen hormones (via the expression of P450 aromatase and estrogen receptors). Aromatase was detected in both the Sertoli and Leydig cells of the testis and was expressed at different levels during the spermatogenic cycle, being highest in the quiescent testis and lowest during germ cell meiosis. ERalpha was found in the Leydig cells surrounding the seminiferous tubules as well as in the epithelial cells of the excurrent canals (rete testis, efferent ductule, and epididymis). ERbeta immunoreactivity was found in both the spermatogonia and Sertoli cells in the testis, and in the epithelial cells of excurrent canals.
Descriptors: reptiles, male turtle, Trachemys scripta, estrogen response system, reproductive tract, estrogen hormones, leydig cells, sertoli and Leydig cells, testis.

Gist, D.H., S.M. Dawes, T.W. Turner, S. Sheldon, and J.D. Congdon (2002). Sperm storage in turtles: A male perspective. Journal of Experimental Zoology. 292(2): 180-186. ISSN: print: 0022-104X; online: 1097-010X.
NAL Call Number: 410 J825
Descriptors: reptiles, turtles, sperm storage, male perspective.

Giugliano, L.G., R.D. Teixeira, G.R. Colli, and S.N. Bao (2002). Ultrastructure of spermatozoa of the lizard Ameiva ameiva, with considerations on polymorphism within the family Teiidae (Squamata). Journal of Morphology 253(3): 264-271. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, lizard, Ameiva ameiva, spermatozoa, ultrastructure, polymorphism, family Teiidae.

Godfrey, M.H. and N. Mrosovsky (2006). Pivotal temperature for green sea turtles, Chelonia mydas, nesting in Suriname. Herpetological Journal 16(1): 55-61. ISSN: 0268-0130.
Descriptors: reptiles, green sea turtles, Chelonia mydas, pivotal temperature, sexual differentiation, nesting, Surinam.

Goldberg, S.R. (2006). Reproductive cycle of the spotted sand lizard, Pedioplanis lineoocellata (Squamata: Lacertidae) from southern Africa. Texas Journal of Science 58(1): 65-72. ISSN: 0040-4403.
Descriptors: reptiles, spotted sand lizard, Pedioplanis lineoocellata, reproductive cycle, southern Africa.

Goldberg, S.R. (2006). Reproductive cycle of the Namaqua sand lizard, Pedioplanis namaquensis (Squamata: Lacertidae), from southern Africa. African Zoology 41(1): 147-149. ISSN: 1562-7020.
NAL Call Number: QL336.Z6
Descriptors: reptiles, Namaqua sand lizard, Pedioplanis namaquensis, reproductive cycle, southern Africa.

Goldberg, S.R. (2006). Note on reproduction of the striped sandveld lizard, Nucras tessellata (squamata : lacertidae) from southern africa. Bulletin of the Maryland Herpetological Society 42(3): 137-139. ISSN: 0025-4231.
NAL Call Number: QL640.M3
Descriptors: reptiles, striped sandveld lizard, Nucras tessellata, reproduction, note, Africa.

Goldberg, S.R. (2006). Reproductive cycle of the bushveld lizard Heliobolus lugubris (Squamata : Lacertidae) from southern africa. Salamandra 42(2-3): 151-154. ISSN: 0036-3375.
Descriptors: reptiles, bushveld lizard, reproductive cycle, sperm formation, prolonged period, testicular cycle, multiple clutches.

Gray, R.L. (2003). Desert Lizards: Captive Husbandry and Propagation, Malabar, USA: Krieger Publishing Company., 130 p. ISBN: 1575241699.
Descriptors: reptiles, desert lizards, care, captive husbandry, propagation.

Gribbins, K.M., D.H. Gist, and J.D. Congdon (2003). Cytological evaluation of spermatogenesis and organization of the germinal epithelium in the male slider turtle, Trachemys scripta. Journal of Morphology 255(3): 337-346. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, male slider turtle, Trachemys scripta, spermatogenesis, germinal epithelium, cytological evaluation, Trachemys scripta.

Gribbins, K.M. and D.H. Gist (2003). Cytological evaluation of spermatogenesis within the germinal epithelium of the male european wall lizard, Podarcis muralis. Journal of Morphology 258(3): 296-306. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, European wall lizard, Podarcis muralis, spermatogenesis, cytological evaluation, germinal epithelium.

Gribbins, K.M., C.S. Happ, and D.M. Sever (2005). Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). V. The temporal germ cell development strategy of the testis. Acta Zoologica Copenhagen 86(4): 223-230. ISSN: 0001-7272.
Descriptors: reptiles, Seminatrix pygaea, black swamp snake, reproductive system, ultrastructure, temporal germ cell development, testis.

Guerrero, S.M., M.L. Calderon, G.R. de Perez, and M.P.R. Pinilla (2004). Morphology of the male reproductive duct system of Caiman crocodilus (Crocodylia, Alligatoridae). Annals of Anatomy 186(3): 235-245. ISSN: 0940-9602.
Descriptors: reptiles, crocodile, alligator, Caiman crocodilus, male, reproductive duct system, morphology.

Hammouche, S., T. Gernigon, and J.M. Exbrayat (2006). [beta]-endorphine et activite ovarienne chez un lezard deserticole, Uromastyx acanthinura. [[beta]-endorphin and ovarian activity in a desert lizard, Uromastyx acanthinura.]. Bulletin De La Societe Zoologique De France 131(1): 5-10. ISSN: 0037-962X.
Descriptors: reptiles, desert lizard, Uromastyx acanthinura, endorphin, ovarian activity, reproductive function, breeding.
Language of Text: French; Summary in English and French.

Harms, H.K., R.T. Paitz, R.M. Bowden, and F.J. Janzen (2005). Age and season impact resource allocation to eggs and nesting behavior in the painted turtle. Physiological and Biochemical Zoology 78(6): 996-1004. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Theory predicts that in long-lived organisms females should invest less energy in reproduction and more in growth and self-maintenance early in life, with this balance shifting as females age and the relative value of each reproductive event increases. We investigated this potential trade-off by characterizing within-population variation in resource allocation to eggs by female painted turtles (Chrysemys picta) and relating this variation to their nesting ecology and life history. We examined lipid and protein allocation to yolks, accounting for both relative female age and seasonal effects (first vs. second clutches within a female). Older females appear to increase their investment in reproduction by producing larger eggs, but these eggs are not disproportionately more lipid or protein rich than the smaller eggs from younger females. Within the nesting season, first clutches have more lipid and protein than second clutches. We also found that younger females nest closer to the water than older females. Our results indicate that trade-offs involving resource allocation and nesting behavior do occur both seasonally and with age, suggesting ontogenetic variation in life-history strategies in this long-lived organism.
Descriptors: reptiles, painted turtle, Chrysemys picta, nesting behavior, age, season, eggs, resource allocation, impact, reproduction, energy.

Hernandez Franyutti, A., M.C. Uribe Aranzabal, and L.J.J. Guillette (2005). Oogenesis in the viviparous matrotrophic lizard Mabuya brachypoda. Journal of Morphology 265(2): 152-164. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: lizards, physiology, oogonia physiology, vitellogenesis physiology, chromosomes, ultrastructure, cytoplasm physiology, ultrastructure, egg yolk physiology, ultrastructure, anatomy, histology, ovulation physiology.

Hua, T.m., C.l. Wang, and B.h. Chen (2004). Stages of embryonic development for Alligator sinensis. Zoological Research 25(3): 263-271. ISSN: 0254-5853.
NAL Call Number: QL1.T85
Descriptors: reptiles, Alligator sinensis, embryonic, development, stages, alligators, crocodiles.
Language of Text: Chinese; Summary in Chinese and English.

Ibarguengoytia, N.R. and L.M. Casalins (2007). Reproductive biology of the southernmost gecko Homonota darwini: convergent life-history patterns among southern hemisphere reptiles living in harsh environments. Journal of Herpetology 41(1): 72-80. ISSN: 0022-1511.
NAL Call Number: QL640.J6
Descriptors: reptiles, southernmost gecko, Homonota darwini, reproductive biology, harsh environments, life history patterns, reproductive cycles, seasons.

Isberg, S.R., P.C. Thomson, F.W. Nicholas, S.G. Barker, and C. Moran (2005). Quantitative analysis of production traits in saltwater crocodiles (Crocodylus porosus): I. reproduction traits. Zeitschrift Fur Tierzuchtung Und Zuchtungsbiologie. [Journal of Animal Breeding and Genetics] 122(6): 361-369. ISSN: 0931-2668.
NAL Call Number: 442.8 Z35
Abstract: Repeatability and phenotypic correlations were estimated for saltwater crocodile reproductive traits. No pedigree information was available to estimate heritability or genetic correlations, because the majority of breeder animals on farms were wild-caught. Moreover, as the age of the female breeders could not be accounted for, egg-size measurements were used as proxies. The reproductive traits investigated were clutch size (total number of eggs laid), number of viable eggs, number of eggs that produced a live, healthy hatchling, hatchability, average snout-vent length of the hatchlings and time of nesting. A second data set was also created comprising binary data of whether or not the female nested. Repeatability estimates ranged from 0.24 to 0.68 for the measurable traits, with phenotypic correlations ranging from -0.15 to 0.86. Repeatability for whether a female nested or not was 0.58 on the underlying scale. Correlations could not be estimated between the measurement and binary traits because of confounding. These estimates are the first published for crocodilian reproduction traits.
Descriptors: alligators, crocodiles, Crocodylus porosus, growth, development, animal husbandry methods, breeding methods, fertility physiology, reproduction physiology, age factors, body weights, measures, clutch size, ovum cytology, reproduction traits.

Isberg, S.R., P.C. Thomson, F.W. Nicholas, S.G. Barker, and C. Moran (2006). Quantitative analysis of production traits in saltwater crocodiles (Crocodylus porosus): III. juvenile survival. Zeitschrift Fur Tierzuchtung Und Zuchtungsbiologie. [Journal of Animal Breeding and Genetics]. 123(1): 44-47. ISSN: 0931-2668.
NAL Call Number: 442.8 Z35
Abstract: Mortality records of 1302 juvenile crocodiles were available for analysis. Crocodiles that were slaughtered during this study were treated as censored (n = 2151). Additionally, records from animals that had neither died nor been slaughtered, i.e. were still alive in the production system (n = 1582), were censored at the last date of data collection. There were a total of 3733 censored records. The data were all full-sib records from 29 parental pairs from Janamba Croc Farm (Northern Territory, Australia), collected over nine consecutive years. Data were analysed using an extension of Cox's proportional hazards model to include frailty (random) terms to account for genetic effects. Heritability of log survival time for juvenile crocodile survival was 0.15 (SE 0.04). The probability of a juvenile crocodile surviving to day 400 was estimated to be only 51%. These results are the first to quantify juvenile survival in a captive breeding situation. Also, this is the first heritability estimate of crocodile survival and is a fundamental element in the development of a genetic improvement programme.
Descriptors: alligators, crocodiles, Crocodylus porosus, genetics, growth, development, breeding methods, mortality, risk factors.

Isberg, S.R., P.C. Thomson, F.W. Nicholas, G.J. Webb, S.C. Manolis, S.G. Barker, and C. Moran (2006). Quantitative analysis of production traits in saltwater crocodiles (Crocodylus porosus): IV. number of scale rows. Zeitschrift Fur Tierzuchtung Und Zuchtungsbiologie. [Journal of Animal Breeding and Genetics]. 123(1): 48-55. ISSN: 0931-2668.
NAL Call Number: 442.8 Z35
Abstract: A total of 3156 scale row records, comprising 1739 full-sibling records from 30 families from Janamba Croc Farm (NT, Australia) and 1417 parent-offspring records from 19 families from Wildlife Management International, Pty Ltd (NT, Australia), collected at each facility using a different method, were analysed using ASReml. The full-sibling heritability estimate for the Janamba data was 0.37 (SE 0.03). The animal model estimate of heritability for the Wildlife Management International (WMI) data, also based predominantly on full-sibling data, was 0.42 (SE 0.04). The counts from three counting methods were evaluated by regression analysis on 100 individuals and were found to be highly correlated. Using the regression relationship, the WMI data were transformed and pooled with the Janamba data to give an animal model heritability estimate of 0.42 (SE 0.04). A multitrait analysis revealed negligible correlations (both phenotypical and genetical) between hatchling size traits and the number of scale rows. There is ample genetic variation to incorporate this trait into a genetic improvement programme for farmed saltwater crocodiles.
Descriptors: alligators, crocodiles, Crocodylus porosus, genetics, growth, development, anatomy, histology, body weights, measures, breeding.

Iverson, J.B. (2002). Reproduction in female razorback musk turtles (Sternotherus carinatus: kinosternidae). Southwestern Naturalist 47(2): 215-224. ISSN: 0038-4909.
NAL Call Number: 409.6 So8
Descriptors: reptiles, female razorback musk turtle, Sternotherus carinatus, reproduction.

Janssen, C. (2003). Artificial incubation of turtle eggs. Exotic DVM 5(5): 11-12. ISSN: 1521-1363.
NAL Call Number: SF981.E96
Descriptors: reptiles, turtle eggs, artificial incubation, dehydration, fetal development, humidity, incubators, temperature.

Kamelin, E.R. and Yu.A. Lukin (2005). Sperm storage in two species of snakes: Asian pit vipers Trimeresurus albolabris (Gray, 1842) and Trimeresurus erythrurus (Cantor, 1839), bred at the Leningrad Zoo terrarium. Russian Journal of Herpetology 12(Suppl.): 158-160. ISSN: 1026-2296.
Descriptors: reptiles, snakes, sperm storage, Asian pit vipers, Trimeresurus albolabris, Trimeresurus erythrurus, Leningrad Zoo.

Katsu, Y., J. Myburgh, S. Kohno, G.E. Swan, L.J.J. Guillette, and T. Iguchi (2006). Molecular cloning of estrogen receptor alpha of the Nile crocodile. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 143(3): 340-346. ISSN: 1095-6433.
Abstract: Estrogens are essential for normal reproductive activity in female and male vertebrates. In female reptiles, they are essential for ovarian differentiation during a critical developmental stage. To understand the molecular mechanisms of estrogen action in the Nile crocodile (Crocodylus niloticus), we have isolated cDNA encoding the estrogen receptor alpha (ERalpha) from the ovary. Degenerate PCR primers specific to ER were designed and used to amplify Nile crocodile cDNA from the ovary. The full-length Nile crocodile ERalpha cDNA was obtained using 5' and 3' rapid amplification cDNA ends (RACE). The deduced amino acid sequence of the Nile crocodile ERalpha showed high identity to the American alligator ERalpha (98%), caiman ER (98%), lizard ER (82%) and chicken ERalpha (92%), although phylogenetic analysis suggested profound differences in the rate of sequence evolution for vertebrate ER sequences. Expression of ERalpha was observed in the ovary and testis of juvenile Nile crocodiles. These data provide a novel tool allowing future studies examining the regulation and ontogenic expression of ERalpha in crocodiles and expands our knowledge of estrogen receptor evolution.
Descriptors: alligators, amino acid sequence, base sequence, gonads metabolism, molecular sequence data, phylogeny, tertiary protein structure, sequence alignment, Nile crocodile, Crocodylus niloticus, molecular cloning, alpha estrogen receptor.

Khalifa, S.A. (2003). Comparative ultrastructure study on spermiogenesis in two lizards, Tarentola annularis and Agama stellio. Journal of Union of Arab Biologists Cairo A Zoology 20: 29-40. ISSN: 1110-5372.
Descriptors: reptiles, lizards, Agama stellio, Tarentola annularis, spermatogenesis, comparative ultrastructure study.
Language of Text: Arabic; English.

Knapp, C.R., J.B. Iverson, and A.K. Owens (2006). Geographic variation in nesting behavior and reproductive biology of an insular iguana (Cyclura cychlura). Canadian Journal of Zoology 84(11): 1566-1575. ISSN: 0008-4301.
NAL Call Number: 470 C16D
Descriptors: reptiles, insular iguana, Cyclura cychlura, nesting behavior, reproductive biology, geographic variation, environmental factors.

Koehler, G., V. Haecky and B. Eidenmuller (2005). Incubation of Reptile Eggs: Basics, Guidelines, Experiences, Krieger Publishing Company: Malabar, FL, 214 p. ISBN: 1575241935.
Descriptors: reptiles, incubation of eggs, basic care, guidelines, reptiles as pets.
Notes: Translation of: Inkubation von Reptilieneiern, translated by Valerie Haecky.

Kohno, S., B.C. Moore, M.P. Gunderson, T.A. Bryan, and L.J.J. Guillette (2006). Androgen receptor in the female reproductive tract of the American alligator, Alligator mississippiensis. Biology of Reproduction(Sp. Iss. SI): 118-119. ISSN: 0006-3363.
Descriptors: reptiles, American alligator, Alligator mississippiensis, female reproductive tract, androgen receptor, meeting.
Notes: Meeting Information: 39th Annual Meeting of the Society for the Study of Reproduction, Omaha, NE, USA; July 29 -August 1, 2006.

Krohmer, R.W. (2004). The male red-sided garter snake (Thamnophis sirtalis parietalis): reproductive pattern and behavior. ILAR Journal 45(1): 54-74. ISSN: print: 1084-2020; online: 0018-9960.
NAL Call Number: QL55.A1I43
Abstract: Among the small group of species (e.g., some temperate zone turtles, snakes, and bats) that exhibit a dissociated reproductive pattern, the red-sided garter snake (Thamnophis sirtalis parietalis) is probably the most well studied. For these species, courtship and mating occur immediately upon emergence from winter dormancy; the gonads remain essentially inactive. Male red-sided garter snakes are a particularly informative animal model for examining the role of neuroendocrine factors associated with reproductive physiology and behavior because unlike species that exhibit an associated reproductive pattern, in which sex steroids initiate and control sexual behavior, reproductive behavior in the male garter snake appears to be independent of circulating sex hormone control. In fact, the only factor associated with the initiation of courtship behavior and mating in the male garter snake is an extended period of low temperature dormancy followed by exposure to warm temperatures. Yet the presence of sex steroid-concentrating neurons within the pathways regulating courtship and mating suggests that sex hormones may be involved in the activation of sexual behavior. Although circulating androgens are elevated upon emergence from hibernation, the initiation of courtship behavior and mating appears to be independent of direct androgen control. Thus steroid hormones may have indirect effects on mating behavior in animals that display "dissociated" reproductive behaviors.
Descriptors: red-sided garter snake, Thamnophis sirtalis parietalis, male, reproductive pattern, behavior, courtship, mating, gonads, reproductive behavior, steroid hormones.

Krohmer, R.W., D. Martinez, and R.T. Mason (2004). Development of the renal sexual segment in immature snakes: effect of sex steroid hormones. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 139(1): 55-64. ISSN: 1095-6433.
Abstract: The renal sexual segment (RSS) of immature Northern and Diamondback Water Snakes and Red-Sided Garter Snakes exhibited varying responses to testosterone or 17beta-estradiol. In both male and female water snakes, kidney mass was not a reliable indicator of hormone treatment, whereas tubule diameter, epithelial height and number of sexual granules responded to hormone treatment. In male water snakes, either hormone initiated granule development by day 16; by day 23, only testosterone increased granule density. Female water snakes receiving either hormone exhibited a small number of granules by day 16; by day 23, granules increased only in Diamondback Water Snakes receiving testosterone. Hormones did not initiate RSS hypertrophy in female Red-Sided Garter Snakes. Tubule diameter and epithelial height of testosterone-treated males exhibited significant hypertrophy, while 17beta-estradiol initiated significant increases in tubule diameter. Garter snakes initiated sexual granule development in response to hormone treatment with males exhibiting a greater response than females and testosterone stimulating a greater response than 17beta-estradiol. Sex steroids appear to mimic sexual maturity in immature snakes initiating RSS development. Whereas the RSS of adult males respond to testosterone, our data suggest specific changes in the RSS of females during maturation effectively negates the effect of 17beta-estradiol evident in immature female RSS.
Descriptors: reptiles, immature snakes, renal sexual segment, development, sex steroids, effect.

Krysko, K.L. (2003). Reproduction in the madagascar leaf-nosed snake, Langaha madagascariensis (Serpentes: Colubridae: Pseudoxyrhophiinae). African Journal of Herpetology 52(1): 61-68. ISSN: 0441-6651.
Descriptors: reptiles, madagascar leafe nosed snake, reproduction.

Krysko, K.L., C.M.I. Sheehy, and a.N. Hooper (2003). Interspecific communal oviposition and reproduction of four species of lizards (Sauria: Gekkonidae) in the lower Florida Keys. Amphibia Reptilia 24(3): 390-396. ISSN: 0173-5373.
Descriptors: reptiles, lizards, four species, reproduction, communal oviposition, Florida Keys.

Kuchling, G. (2006). Endoscopic sex determination in juvenile freshwater turtles, Erymnochelys madagascariensis: morphology of gonads and accessory ducts. Chelonian Conservation and Biology 5(1): 67-73. ISSN: 1071-8443.
Descriptors: reptiles, fresh water turtles, Erymnochelys madagascariensis, endoscopic sex determination, juvenile, gonads, accessory ducts, morphology.

Ladyman, M., X. Bonnet, O. Lourdais, D. Bradshaw, and G. Naulleau (2003). Gestation, thermoregulation, and metabolism in a viviparous snake, Vipera aspis: evidence for fecundity-independent costs. Physiological and Biochemical Zoology 76(4): 497-510. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Oxygen consumption of gestating Aspic vipers, Vipera aspis (L.), was strongly dependent on body temperature and mass. Temperature-controlled, mass-independent oxygen consumption did not differ between pregnant and nonpregnant females. Maternal metabolism was not influenced during early gestation by the number of embryos carried but was weakly influenced during late gestation. These results differ from previous investigations that show an increase in mass-independent oxygen consumption in reproductive females relative to nonreproductive females and a positive relationship between metabolism and litter size. These data also conflict with published field data on V. aspis that show a strong metabolic cost associated with reproduction. We propose that, under controlled conditions (i.e., females exposed to precise ambient temperatures), following the mobilisation of resources to create follicles (i.e., vitellogenesis), early gestation per se may not be an energetically expensive period in reproduction. However, under natural conditions, the metabolic rate of reproductive females is strongly increased by a shift in thermal ecology (higher body temperature and longer basking periods), enabling pregnant females to accelerate the process of gestation. Combining both laboratory and field investigation in a viviparous snake, we suggest that reproduction entails discrete changes in the thermal ecology of females to provide optimal temperatures to the embryos, whatever their number. This results in the counterintuitive notion that metabolism may well be largely independent of fecundity during gestation, at least in an ectothermic reptile.
Descriptors: reptiles, viviparous snake, Vipera aspis, gestation, thermoregulation, metabolism, fecundity, body temperature, oxygen consumption.

LeMaster, M.P. and R.T. Mason (2002). Variation in a female sexual attractiveness pheromone controls male mate choice in garter snakes. Journal of Chemical Ecology 28(6): 1269-1285. ISSN: print: 0098-0331; online: 1573-1561.
Abstract: Male red-sided garter snakes (Thamnophis sirtalis parietalis) display a courtship preference for larger females during the breeding season. Utilizing behavioral experiments and chemical analyses, we tested the hypothesis that males can discriminate among females of varying size solely by means of the sexual attractiveness pheromone, a previously characterized sex pheromone composed of a homologous series of long-chain saturated and omega-9 cis-unsaturated methyl ketones contained in the skin lipids of females. When presented with skin lipid extracts from large and small females, a greater proportion of males displayed courtship behaviors to large female extracts. This demonstrates that there is an intrinsic property of the female skin lipids that allows males to differentiate among large and small females. Analysis of the sexual attractiveness pheromone revealed that the necessary variation exists for this pheromone to function as a reliable indicator to males of female body size. Specifically, we observed a strong correlation between female snout-vent length and the relative concentration of saturated and omega-9 cis-unsaturated methyl ketones composing the pheromone; smaller females expressed pheromone profiles higher in saturated methyl ketones. while larger females expressed pheromone profiles dominated by unsaturated methyl ketones. The results of this study suggest that male red-sided garter snakes utilize compositional variation in the female sexual attractiveness pheromone to differentiate among potential mates of varying size.
Descriptors: reptiles, garter snakes, Thamnophis sirtalis parietalis, female sexual attractiveness, variation, pheromone controls, mate choice, preference for larger females.

Lewis, W.G.V. (2003). Dystocia in a tortoise. Exotic DVM 5(1): 14. ISSN: 1521-1363.
NAL Call Number: SF981.E96
Descriptors: reptiles, dystocia, tortoise, case reports, clinical aspects, diagnosis, surgical operations.

Litzgus, J.D. (2006). Sex differences in longevity in the Spotted Turtle (Clemmys guttata). Copeia 2006(2): 281-288. ISSN: 0045-8511.
Descriptors: reptiles, spotted turtle, Clemmys guttata, sex differences, longivity, egg, hatching rate, survival.

Litzgus, J.D. and T.A. Mousseau (2006). Geographic variation in reproduction in a freshwater turtle (Clemmys guttata). Herpetologica 62(2): 132-140. ISSN: 0018-0831.
NAL Call Number: QL640.H4
Descriptors: reptiles, freshwater turtle, Clemmys guttata, reproduction, geographic variation.

Mader, D.R. (2002). Reproductive surgery in the green iguana. Proceedings of the North American Veterinary Conference 16(16): 923-924. ISSN: 0003-1488.
NAL Call Number: SF605.N672
Descriptors: reptiles, Iguana, ovariectomy, ovulation, females, surgery, reproductive, meeting.
Notes: In the volume: Small Animal and Exotics. Part of a three volume set. Meeting held January 12-16, 2002, Orlando, Florida.

Mahmoud, I.Y., J.R. Paulson, M. Dudley, J.S. Patzlaff, and A.Y. Al Kindi (2004). Secretory proteins in the reproductive tract of the snapping turtle, Chelhydra serpentina. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 139(4): 487-494. ISSN: 1095-6433.
Abstract: SDS-polyacrylamide gel electrophoresis was used to separate the secretory proteins produced by the epithelial and endometrial glands of the uterine tube and uterus in the snapping turtle Chelydra serpentina. The proteins were analyzed throughout the phases of the reproductive cycle from May to August, including preovulatory, ovulatory, postovulatory or luteal, and vitellogenic phases. The pattern of secretory proteins is quite uniform along the length of the uterine tube, and the same is true of the uterus, but the patterns for uterine tube and uterus are clearly different. We identify 13 major proteins in C. serpentina egg albumen. Bands co-migrating with 11 of these are found in the uterine tube, but at most 4 are found in the uterus, suggesting that the majority of the albumen proteins are most likely secreted in the uterine tube, not in the uterus. Although some of the egg albumen proteins are present in the uterine tube only at the time of ovulation, most of the bands corresponding to albumen proteins are present throughout the breeding season even though the snapping turtle is a monoclutch species. These results suggest that the glandular secretory phase in the uterine tube is active and quite homogeneous in function regardless of location or phase of the reproductive cycle.
Descriptors: reptiles, snapping turtle, Chelydra serpentina, secretory proteins, reproductive tract, reproductive cycle.

Martinez Torres, M., M. Elena Hernandez Caballero, C. Alvarez Rodriguez, J. Alba Luis Diaz, and G. Ortiz Lopez (2003). Luteal development and progesterone levels during pregnancy of the viviparous temperate lizard Barisia imbricata imbricata (Reptilia: Anguidae). General and Comparative Endocrinology 132(1): 55-65. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: The relationship between plasma progesterone (P(4)) levels and the formation and degeneration of the corpus luteum (CL) was assessed monthly during gestation of the viviparous lizard Barisia imbricata imbricata. Histochemical activity of the delta(5-4) isomerase 3 beta-hydroxysteroide dehydrogenase (delta(5-4)3beta-HSD) in the luteal tissue and embryonic development were also observed. Females were gravid throughout winter and great part of spring (late November or early December until late May or early June). Corpus luteum development occurred in the first third of gestation (December and January) when the embryo reached developmental stage 27. Four sequential stages were identified during development and three stages during regression of the CL. The follicular and thecal tissue participated in the formation of the luteal cell mass. According to Xavier's classification, the CL of B. i. imbricata is a subtype from Type III. The activity of delta(5-4)3beta-HSD was observed mainly in the luteal cell mass. The first degenerative changes in the CL were observed in the early second third of the gestation and continued gradually until parturition. Progesterone levels increased in early pregnancy and reached its highest level during January (3.07+/-1.04 ng/ml) when mature corpora lutea were present. Gradual diminution in progesterone concentrations occurred in the second and last third of pregnancy and coincided with advanced degenerative changes and diminution in histochemical activity of delta(5-4)3beta-HSD in the luteal tissue. These observations suggest that the CL is the major source of progesterone during pregnancy of B. i. imbricata.
Descriptors: reptiles, lizard, Barisia imbricata imbricata, pregnancy, luteal development, progesterone levels, corpus luteum, gestation, embryo.

Masunaga, G. and H. Ota (2003). Growth and reproduction of the sea snake, Emydocephalus ijimae, in the central Ryukyus, Japan: a mark and recapture study. Zoological Science 20(4): 461-470. ISSN: 0289-0003.
NAL Call Number: QL1.Z68
Abstract: A mark and recapture study was carried out for three years on a population of the Ijima's sea snake, Emydocephalus ijimae, in the coastal shallow water of Zamamijima Island, central Ryukyus, Japan. The relatively high recapture (47% of 167 marked snakes) suggests that E. ijimae is a particularly philopatric, sedentary species among the sea snakes. The sex ratio (male: female), approximately 1.6:1, significantly skewed from 1:1. The growth rate in SVL declined with growth, with females thoroughly growing better than males. Males and females were estimated to begin reproductive activity in the second or third summer and the third spring after birth, respectively. Frequency of female reproduction is guessed to vary from annual to biennial, or even less frequent.
Descriptors: reptiles, sea snake, Emydocephalus ijimae, growth, reproduction, recapture study, Japan.

Mattson, J.K., A.T. Devries, S.M. Mcguire, J. Krebs, E.E. Louis, and N.M. Loskutoff (2007). Successful artificial insemination in the corn snake (Elaphe gutatta), using fresh and cooled semen. Reproduction, Fertility, and Development 19(1): 240. ISSN: 1031-3613.
NAL Call Number: QP251.R47
Descriptors: reptiles, corn snake, artificial insemination, fresh cooled semen.
Notes: Meeting Information: 33rd Annual Conference of the Internatinal Embryo Transfer Society, Kyoto, Japan; January 6-January 10, 2007.

Mendonca, M.T., D. Daniels, C. Faro, and D. Crews (2003). Differential effects of courtship and mating on receptivity and brain metabolism in female red-sided garter snakes (Thamnophis sirtalis parietalis). Behavioral Neuroscience 117(1): 144-149. ISSN: 0735-7044.
NAL Call Number: QP351.B45
Abstract: In the female red-sided garter snake (Thamnophis sirtalis parietalis), the loss of receptivity following intromission during mating can be prevented by injection of a local anesthetic (tetracaine) in the cloacal region prior to courtship and mating. Females that were courted and then mated had significantly higher uptake of radio-labeled [14C]2-fluoro-2-deoxyglucose (2-DG) in the preoptic area (25%) and significantly lower uptake in the ventromedial hypothalamus (-20%) compared with females that were courted but not mated. Tetracaine-treated females had accumulation patterns similar to courted but unmated females and to females exposed only to other females. These results suggest that in the female red-sided garter snake, sensory input from the cloaca during mating alters patterns of metabolism in those brain areas most often associated with female sexual behavior.
Descriptors: reptiles, red-sided garter snakes, Thamnophis sirtalis parietalis, courtship, mating recptivity effects, brain metabolism, female, local anesthetic.

Mitchell, M.A., T.W. Adamson, C.B. Singleton, M.K. Roundtree, R.W. Bauer, and M.J. Acierno (2007). Evaluation of a combination of sodium hypochlorite and polyhexamethylene biguanide as an egg wash for red-eared slider turtles (Trachemys scripta elegans) to suppress or eliminate Salmonella organisms on egg surfaces and in hatchlings. American Journal of Veterinary Research 68(2): 158-164. ISSN: 0002-9645.
NAL Call Number: 41.8 Am3A
Abstract: OBJECTIVE: To evaluate a combination of 2 nonantibiotic microbicide compounds, sodium hypochlorite (NaOCl) and polyhexamethylene biguanide (PHMB), as a treatment to suppress or eliminate Salmonella spp from red-eared slider (RES) turtle (Trachemys scripta elegans) eggs and hatchlings. SAMPLE POPULATION: 2,738 eggs from 8 turtle farms in Louisiana. PROCEDURES: Eggs were randomly sorted into 3 or, when sufficient eggs were available, 4 treatment groups as follows: control, pressure-differential egg treatment with NaOCl and gentamicin, NaOCl and PHMB bath treatment, and pressure-differential egg treatment with NaOCl and PHMB. Bacterial cultures were performed from specimens of eggs and hatchlings and evaluated for Salmonella spp. RESULTS: RES turtle eggs treated with NaOCl and PHMB as a bath (odds ratio [OR], 0.2 [95% confidence interval (CI), 0.1 to 0.3]) or as a pressure-differential dip (OR, 0.01 [95% CI, 0.001 to 0.07]) or with gentamicin as a pressure-differential dip (OR, 0.1 [95% CI, 0.06 to 0.2]) were significantly less likely to have Salmonella-positive culture results than control-group eggs. CONCLUSIONS AND CLINICAL RELEVANCE: Concern over reptile-associated salmonellosis in children in the United States is so great that federal regulations prohibit the sale of turtles that are < 10.2 cm in length. Currently, turtle farms treat eggs with gentamicin solution. Although this has reduced Salmonella shedding, it has also resulted in antimicrobial resistance. Results of our study indicate that a combination of NaOCl and PHMB may be used to suppress or eliminate Salmonella spp on RES turtle eggs and in hatchlings.
Descriptors: reptiles, red eared slider turtles, Trachemys scripta elegans, sodium hypochlorite, polyhexamethylene, egg wash, Salmonella organisms, hatchlings.

Mubarak, M. (2006). Ultrastructure of sperm tail differentiation of the lizard Stenodactylus dorie (Squamata, Reptilia). Journal of Biological Sciences 6(1): 187-192. ISSN: 1727-3048.
NAL Call Number: QH301.J687
Descriptors: reptiles, lizard, Stenodactylus dorie, sperm tail differentiation, ultrastructural study.

Munns, S. and C. Daniels (2007). Breathing with big babies: ventilation and oxygen consumption during pregnancy in the lizard Tiliqua rugosa. Physiological and Biochemical Zoology 80(1): 35-45. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: We determined the effects of high gestational loads on ventilation and the rate of oxygen consumption (VO2) in the scincid lizard Tiliqua rugosa. Tiliqua rugosa is a large viviparous lizard that gives birth to one to four young after 6-7 mo gestation. Pregnant females gave birth to large young, weighing 89.5+/-5.9 g, which represents 21.6%+/-2.6% of maternal body mass. As the embryos developed, they occupied an increasingly large proportion of the body cavity, decreasing food consumption and compressing the gastrointestinal tract. Computerized axial tomography scans demonstrated that the lungs were compressed and/or regionally collapsed by the developing embryos, potentially compromising ventilation. Both minute ventilation (VE) and tidal volume decreased as gestation progressed, but no compensatory changes in breathing frequency or in the duration of the nonventilatory period were observed. The total rate of VO2, consisting of contributions from both maternal and fetal tissues, did not change during gestation, suggesting that maternal VO2 decreases as fetal VO2 increases. Pregnant females demonstrated a decreased ventilatory response to increased respiratory drive (triggered via inhalation of hypoxic hypercapnic gas), which may be associated with the increased energetic cost of ventilating a compressed lung or the desensitization of chemoreceptors during gestation. The decreased ability of the respiratory system to respond to increased respiratory drive may have important consequences for locomotor performance and predator avoidance in pregnant lizards.
Descriptors: reptiles, lizards, Tiliqua rugosa, oxygen consumption, ventilation, pregnancy, gestational loads, effects, large young, birth.

Nakamura, M. (2004). [Sex determination in reptiles and amphibians: with special reference to the mechanism of temperature-dependent sex determination]. Tanpakushitsu Kakusan Koso; Protein, Nucleic Acid, Enzyme 49(2): 124-129. ISSN: 0039-9450.
Descriptors: amphibian, reptiles, embryology, embryology, sex determination genetics, temperature, amphibian genetics, androgens physiology, dna binding proteins genetics, physiology, estrogens physiology, fushi tarazu transcription factors, gene expression, gonads embryology, high mobility group proteins genetics, physiology, homeodomain proteins, receptors, cytoplasmic, nuclear, reptiles genetics, sex chromosomes genetics, sex reversal, transcription factors genetics, transcription factors physiology.
Language of Text: Japanese.

Orrell, K.S., J.D. Congdon, T.A. Jenssen, R.H. Michener, and T.H. Kunz (2004). Intersexual differences in energy expenditure of Anolis carolinensis lizards during breeding and postbreeding seasons. Physiological and Biochemical Zoology 77(1): 50-64. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Although the amount of energy that males and females invest in reproduction is an integral component of theories explaining the evolution of particular mating strategies, few studies have actually determined the amount of energy that each sex allocates to reproduction. We compared how energy is expended by male and female Anolis carolinensis lizards during both the breeding and postbreeding seasons. We used laboratory respirometry to determine resting metabolic rates (RMRs) of inactive, freshly captured lizards and the doubly labeled water technique to determine field metabolic rates (FMRs) of free-ranging lizards. Both RMRs and FMRs were influenced by body mass but not by sex. Season did not influence FMRs; however, RMRs of both sexes increased approximately 40% from the breeding to the postbreeding season. The seasonal increase in RMRs was attributed to a postreproductive increase in feeding rate and specific dynamic action. We used RMRs, FMRs, and thermal profiles of lizards to calculate energy budgets for breeding and postbreeding seasons. Energy budgets partitioned daily field energy (DFE; calculated from FMRs) into daily activity energy (DAE) and daily resting energy (DRE; calculated from RMRs). Energy expended for reproduction was estimated as DAE during the breeding season plus egg production (for females). Despite males having 40% greater body mass, females expended 46% more energy for reproduction than did males (906 and 619 J/d, respectively). Total metabolizable energy (TME=DFE+egg production for females) expended during the breeding season was similar for males and females (1,280 and 1,365 J/d, respectively). Although TME of females decreased 44% from the breeding to the postbreeding season (1,365 vs. 766 J/d), TME of males was similar during both seasons (1,280 vs. 1,245 J/d). There were both seasonal and sexual differences in DRE and DAE. Compared with most lizards from semiarid/desert habitats, A. carolinensis in a temperate habitat expends more total energy during the breeding season, allocates more energy to eggs, and appears to have more total energy available for reproduction.
Descriptors: reptiles, lizards, Anolis carolinensis, breeding, postbreeding seasons, energy expenditure, intersexual differences, reproduction, energy budgets.

Painter, D., D.H. Jennings, and M.C. Moore (2002). Placental buffering of maternal steroid hormone effects on fetal and yolk hormone levels: a comparative study of a viviparous lizard, Sceloporus jarrovi, and an oviparous lizard, Sceloporus graciosus. General and Comparative Endocrinology 127(2): 105-116. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Descriptors: reptiles, viviparous and oviparous lizards, placental buffering, maternal steroid hormone, effects, fetal, yolk, hormone levels, comparative study.

Pieau, C. and M. Dorizzi (2004). Oestrogens and temperature-dependent sex determination in reptiles: All is in the gonads. Journal of Endocrinology 181(3): 367-377. ISSN: 0022-0795.
NAL Call Number: 448.8 J8293
Abstract: In many species of oviparous reptiles, the first steps of gonadal sex differentiation depend on the incubation temperature of the eggs. Feminization of gonads by exogenous oestrogens at a male-producing temperature and masculinization of gonads by antioestrogens and aromatase inhibitors at a female-producing temperature have irrefutably demonstrated the involvement of oestrogens in ovarian differentiation. Nevertheless, several studies performed on the entire gonad/adrenal/mesonephros complex failed to find differences between male- and female-producing temperatures in oestrogen content, aromatase activity and aromatase gene expression during the thermosensitive period for sex determination. Thus, the key role of aromatase and oestrogens in the first steps of ovarian differentiation has been questioned, and extragonadal organs or tissues, such as adrenal, mesonephros, brain or yolk, were considered as possible targets of temperature and sources of the oestrogens acting on gonadal sex differentiation.In disagreement with this view, experiments and assays carried out on the gonads alone, i.e. separated from the adrenal/mesonephros, provide evidence that the gonads themselves respond to temperature shifts by modifying their sexual differentiation and are the site of aromatase activity and oestrogen synthesis during the thermosensitive period. Oestrogens act locally on both the cortical and the medullary part of the gonad to direct ovarian differentiation. We have concluded that there is no objective reason to search for the implication of other organs in the phenomenon of temperature-dependent sex determination in reptiles. From the comparison with data obtained in other vertebrates, we propose two main directions for future research: to examine how transcription of the aromatase gene is regulated and to identify molecular and cellular targets of oestrogens in gonads during sex differentiation, in species with strict genotypic sex determination and species with temperature-dependent sex determination.
Descriptors: reptiles, sex determination, gonads, estrogens, temperture dependent, incubation temperature.

Pleguezuelos, J.M. and M. Feriche (2006). Reproductive ecology of a Mediterranean ratsnake, the ladder snake Rhinechis scalaris (schinz, 1822). Herpetological Journal 16(2): 177-182. ISSN: 0268-0130.
Descriptors: reptiles, rat snake, ladder snake, Rhinechis scalaris, reproductive ecology, newborn size, prey size, hibernation.

Radder, R.S., B.A. Shanbhag, and S.K. Saidapur (2004). Yolk partitioning in embryos of the lizard, Calotes versicolor: maximize body size or save energy for later use? Journal of Experimental Zoology. Part A, Comparative Experimental Biology 301(9): 783-785. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Abstract: The hatchlings of Calotes versicolor and other congeners retain residual yolk for immediate post-hatching needs. Excision of 8% yolk (approximately equal residual yolk) from the eggs resulted in smaller hatchlings when compared to those emerging from sham operated eggs. However, hatchlings in both groups retained the same amount of residual yolk. The findings suggest that residual yolk in hatchlings of C. versicolor is an important part of the energy budget set aside by developing embryos and that the advantages of large hatchling size are counter balanced by selection for residual yolk.
Descriptors: reptiles, lizard, Calotes versicolor, partitioning in embryos, maximize body size, energy use, hatchlings, yolk partitioning, residual yolk.

Ramirez Bautista, A., C.A. Maciel Mata, and M.A. Martinez Morales (2005). Reproductive cycle of the viviparous lizard Sceloporus grammicus (Squamata: phrynosomatidae) from Pachuca, Hidalgo, Mexico. Acta Zoologica Sinica 51(6): 998-1005. ISSN: 0001-7302.
Descriptors: reptiles, viviparous lizard, Sceloporus grammicus, reproductive cycle, breeding season, Mexico.
Language of Text: Chinese; English.

Ramirez Bautista, u. (2003). Some reproductive characteristics of a tropical arid lizard assemblage from Zapotitlan Salinas, Puebla, Mexico. Herpetological Review 34(4): 328-331. ISSN: 0018-084X.
NAL Call Number: QL640.H47
Descriptors: reptiles, tropical lizard, reproductive characteristics, Mexico.

Ramirez Sandoval, E., A. Ramirez Bautista, and L.J. Vitt (2006). Reproduction in the lizard Phyllodactylus lanei (Squamata: Gekkonidae) from the Pacific Coast of Mexico. Copeia 2006(1): 1-9. ISSN: 0045-8511.
Descriptors: reptiles, lizard, Phyllodactylus lanei, reproduction, biology, Pacific coast, Mexico.
Language of Text: English; Spanish.

Rivas, J.A. and G.M. Burghardt (2005). Snake mating systems, behavior, and evolution: the revisionary implications of recent findings. Journal of Comparative Psychology 119(4): 447-454. ISSN: 0735-7036.
Descriptors: green anacondas snake, mating systems, behavior, evolution, behavior, recent findings, polygny.

Russo, M., G. Troncone, F.M. Guarino, F. Angelini, and P. Chieffi (2005). Estrogen-induced Akt-1 activity in the lizard (Podarcis s. sicula) testis. Molecular Reproduction and Development 71(1): 52-57. ISSN: 1040-452X.
NAL Call Number: QP251.M64
Descriptors: reptiles, lizard, Podarcis s. sicula, testis, estrogen induced Akt-1, activity, reproduction, mating.

Sakata, J.T., S.C. Woolley, A. Gupta, and D. Crews (2003). Differential effects of testosterone and progesterone on the activation and retention of courtship behavior in sexual and parthenogenetic whiptail lizards. Hormones and Behavior 43(5): 523-530. ISSN: 0018-506X.
NAL Call Number: QP801.H7H64
Abstract: Both testosterone (T) and progesterone (P) facilitate the expression of male-typical sexual behavior in a variety of animals, including rodents and lizards. In two species of whiptail lizards, Cnemidophorus inornatus and C. uniparens, both hormones elicit the full repertoire of courtship behavior. However, the relative efficacy of the two hormones is unknown. In Experiments 1 and 2 we assessed differences in capacity of exogenous T and P to induce male-typical courtship behavior in gonadectomized whiptail lizards. In both species, individuals implanted with T showed more frequent courtship behavior relative to those implanted with P or cholesterol. In Experiments 3 and 4 we examined whether T and P differentially affected the retention of courtship behavior following implant removal. In both species, individuals implanted with T showed more courtship behavior following implant removal than those previously given P. In these experiments, implants were removed at a time when individuals in both groups were behaviorally similar; therefore, the differences in behavior following implant removal were not due to differences in the amount of courtship experience. Taken together, the hormone that was more effective at activating courtship behavior was also more effective at maintaining courtship behavior following implant removal. In summary, though both T and P can elicit identical sexual behaviors in both whiptail species, T has a greater and more lasting effect on courtship behavior and possibly on the neural circuits underlying courtship behavior.
Descriptors: reptiles, whiptail lizards, Cnemidophorus inornatus and C. uniparens, courtship, behavior, testosterone, progesterone, differential effects, activation, retention.

Sarkar, S., N.K. Sarkar, and B.R. Maiti (2003). Oviductal sperm storage structure and their changes during the seasonal (dissociated) reproductive cycle in the soft-shelled turtle Lissemys punctata punctata. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 295(1): 83-91. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Descriptors: reptiles, soft shelled turtle, Lissemys punctata punctata, oviductal sperm, storage stucture, seasonal changes.

Schmidt de Aguiar, L.F. and M. Di Bernardo (2005). Reproduction of the water snake Helicops infrataeniatus (Colubridae) in southern Brazil. Amphibia Reptilia 26(4): 527-533. ISSN: 0173-5373.
Descriptors: reptiles, water snake, Helicops infrataeniatus, reproduction, Brazil.

Schmidt, D. (2004). Zur Reproduktion von Schlangen im Terrarium Aufgaben - Fakten - Probleme. [The reproduction of snakes in the terrarium. Duties - facts - problems.]. Draco 5(1): 22-36 Nr 17. ISSN: 1439-8168.
Descriptors: reptiles, snakes, reproduction, terrarium, facts, duties, problems.
Language of Text: German.

Selcer, K.W., S. Smith, J.W. Clemens, and B.D. Palmer (2005). Androgen receptor in the oviduct of the turtle, Trachemys scripta. Comparative Biochemistry and Physiology. Part B, Biochemistry and Molecular Biology 141(1): 61-70. ISSN: 1096-4959.
Abstract: Circulating androgens reach high concentrations in females of some reptiles and amphibians. We are testing the hypothesis that androgens can act directly in female reptilian reproductive tissues, via the androgen receptor. In this study, we sought to determine if androgen receptors are present in the oviduct of the turtle, Trachemys scripta, using radioligand-binding assays and immunological assays. An androgen-binding site was detected in turtle oviductal cytosol and oviductal nuclear extract by radioligand binding assay, using (3)H-dihydrotestosterone (DHT) as the ligand. This site was saturable (B(max)=11 pmol/g tissue), had a high affinity (10(-10) M), and showed specificity typical of androgen receptors (DHT>testosterone, progesterone>>estradiol, cortisol). Western blotting using an anti-androgen receptor antibody revealed a band of immunoreactivity in oviductal cytosol at approximately 115 kDa, and a more prominent band at 50 kDa, possibly indicating a truncated form of the androgen receptor. Immunohistochemistry revealed crossreactivity of the androgen receptor antibody against oviductal glandular cells but not against oviductal luminal epithelial or muscularis cells. The presence of androgen receptor in the turtle oviduct suggests that androgens have a role in female reproduction and that their action can be mediated directly by androgen receptor.
Descriptors: turtle, Trachemys scripta, oviduct, androgen receptor, reproductive tissues, androgen receptor, female reproduction, assay.

Sever, D.M. (2004). Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). IV. Occurrence of an ampulla ductus deferentis. Journal of Morphology 262(3): 714-730. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Abstract: The distal end of the ductus deferens of Seminatrix pygaea (Cope) differs from more proximal portions of the tube by possessing a highly fluctuated epithelium. Similar morphology has been reported in this area in one lizard and some mammals and the region has been designated in these taxa as the ampulla ductus deferentis. In this study, light and transmission electron microscopy were used to study the posterior ductus deferens in S. pygaea and compare the histology in this region to more proximal regions of the duct and to descriptions of the ampulla of other species. Seminatrix pygaea stores sperm throughout the ductus deferens during the entire year. The epithelium of the ductus deferens is not secretory, but the presence of numerous small apical vesicles indicates a role in fluid absorption. In addition to the highly folded epithelium, clusters of sperm nuclei are more intimately associated with the apical ampullary epithelium than elsewhere in the ductus deferens. No evidence of phagocytosis of sperm was found. In contrast, the ampulla of mammals and presumably the lizard Calotes versicolor is glandular and phagocytic. The common character shared by the squamates and mammals with specializations in this area is the folded epithelium, and whether this is due to shared ancestry with amniotes or is homoplastic is unresolved.
Descriptors: reptiles, black swamp snake, Seminatrix pygaea, lizard, Calotes versicolor, reproductive system, ultrastructure, ampulla ductus deferentis.

Sever, D.M. and W.C. Hamlett (2002). Female sperm storage in reptiles. Journal of Experimental Zoology 292(2): 187-199. ISSN: print: 0022-104X; online: 1097-010X.
NAL Call Number: 410 J825
Descriptors: reptiles, fertilization, oviducts, female sperm storage, reptiles physiology, vagina anatomy.

Sever, D.M., R.A. Stevens, T.J. Ryan, and W.C. Hamlett (2002). Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). III. Sexual segment of the male kidney. Journal of Morphology 252(3): 238-254. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, black swamp snake, Seminatrix pygaea, reproductive system, ultrastructure, male kidney, sexual segment.

Shanbhag, B.A., S.K. Saidapur, and R.S. Radder (2003). Lowering body temperature induces embryonic diapause during prolonged egg retention in the lizard, Calotes versicolor. Die Naturwissenschaften 90(1): 33-35. ISSN: print: 0028-1042; online: 1432-1904.
Abstract: The lizard Calotes versicolor delays oviposition of oviductal eggs for as long as 6 months or more under unfavourable conditions. During this period of prolonged egg retention, the growth of oviductal embryos is arrested at stage 34. The present study shows for the first time among reptiles that the "embryonic diapause" is manifested by the gravid females by lowering their body temperature ( T(b)) by 3-5 degrees C during the period of egg retention by mechanism(s) presently unknown.
Descriptors: reptiles, lizard, Calotes versicolor, prolonged egg retention, body temperature, lowering, embryonic diapause.

Shanbhag, B.A. (2003). Reproductive strategies in the lizard, Calotes versicolor. Current Science 84(5): 646-652. ISSN: 0011-3891.
Descriptors: reptiles, lizard, Calotes versicolor, reproductive strategies.

Shanbhag, B.A. (2002). Reproductive biology of Indian reptiles. PINSA B 68(6): 497-528. ISSN: 0073-6600.
Descriptors: reptiles, Indian, reproductive biology.
Notes: PINSA-B (Proceedings of the Indian National Science Academy, Part-B) Special issue devoted to Stress Response.

Shine, R. (2003). Reproductive strategies in snakes. Proceedings of the Royal Society of London. Series B, Biological Sciences 270(1519): 995-1004. ISSN: 0080-4649.
Abstract: Snakes of both sexes display remarkable flexibility and diversity in their reproductive tactics. Many features of reproduction in female snakes (such as reproductive mode and frequency, seasonality and multiple mating) allow flexible maternal control. For example, females can manipulate not only the genotypes of their offspring (through mate choice or enhanced sperm competition) but also the phenotypes of their offspring (through allocation 'decisions', behavioural and physiological thermoregulation, and nest-site selection). Reliance on stored energy ('capital') to fuel breeding results in low frequencies of female reproduction and, in extreme cases, semelparity. A sophisticated vomeronasal system not only allows male snakes to locate reproductive females by following scent trails, but also facilitates pheromonally mediated mate choice by males. Male-male rivalry takes diverse forms, including female mimicry and mate guarding; combat bouts impose strong selection for large body size in males of some species. Intraspecific (geographical) variation and phenotypic plasticity in a wide array of reproductive traits (offspring size and number; reproductive frequency; incidence of multiple mating; male tactics such as mate guarding and combat; mate choice criteria) provide exceptional opportunities for future studies.
Descriptors: reptiles, snakes, reproductive strategies, tactics, multiple mating, thermoregulation, vermonasal system.

Shine, R., T. Langkilde, and R.T. Mason (2003). Cryptic forcible insemination: male snakes exploit female physiology, anatomy, and behavior to obtain coercive matings. American Naturalist 162(5): 653-667. ISSN: 0003-0147.
NAL Call Number: 470 Am36
Abstract: Whether males can inseminate uncooperative females is a central determinant of mating system evolution that profoundly affects the interpretation of phenomena such as multiple mating by females, mate choice, reproductive seasonality, and courtship tactics. Forcible insemination is usually inferred from direct physical battles between the sexes and has been dismissed on intuitive grounds for many kinds of animals. For example, snakes have elongate flexible bodies (making it difficult for a male to restrain a female physically), males are typically smaller than females, and copulation requires female cloacal gaping to enable intromission. Male garter snakes (Thamnophis sirtalis) do not display any overt aggression during courtship and simply lie over the female and exhibit rhythmic pulsating caudocephalic waves of muscular contraction; previous studies have interpreted this behavior as a mechanism for eliciting female receptivity. In contrast, we show that male garter snakes forcibly inseminate females. They do so by taking advantage of specific features of snake physiology, respiratory anatomy, and antipredator behavior. The snake lung extends along most of the body, with the large posterior section (the saccular lung) lacking any respiratory exchange surface. Rhythmic caudocephalic waves by courting male garter snakes push anoxic air from the saccular lung forward and across the respiratory surfaces such that females cannot obtain oxygen. Their stress response involves cloacal gaping, which functions in other contexts to repel predators by extruding feces and musk but in this situation permits male intromission. Thus, superficially benign courtship behaviors may involve cryptic coercion even in species for which intuition dismisses any possibility of forcible insemination.
Descriptors: reptiles, male snakes, garter snakes, Thamnophis sirtalis, forcible insemination, female, physiology, anatomy, behavior, matings.

Staljanssens, P. and J. Nijs (2002). Captive care and reproduction of the common snapping turtle, Chelydra s. serpentina. Podarcis 3(2): 34-42. ISSN: 1567-3871.
Descriptors: reptiles, common snapping turtle, Chelydra serpentina, captive care, reproduction.

Stewart, J.R. and K.R. Brasch (2003). Ultrastructure of the placentae of the natricine snake, Virginia striatula (Reptilia: Squamata). Journal of Morphology 255(2): 177-201. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: reptiles, natricine snake, Virginia striatula, placenta, ultrastructure.

Stewart, J.R. and M.B. Thompson (2004). Placental ontogeny of the Tasmanian scincid lizard, Niveoscincus ocellatus (Reptilia: Squamata). Journal of Morphology 259(2): 214-237. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: lizards, Niveoscincus ocellatus, anatomy, histology, placenta anatomy, histology, placentation, placental ontogeny, pregnancy, uterus anatomy, histology.

Taylor, J.E. (2004). Reproduction in sympatric lizards: comparison of two species of Ctenotus (Scincidae) in south-eastern Australia. Australian Journal of Zoology 52(6): 649-666. ISSN: 0004-959X.
NAL Call Number: 410 Au73
Descriptors: reptiles, sympatric lizards, Ctenotus robustus, Ctenotus taeniolatus, reproduction, comparison of two species, Australia.

Thompson, M.B. and B.K. Speake (2002). Energy and nutrient utilisation by embryonic reptiles. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 133(3): 529-538. ISSN: 1095-6433.
Abstract: Most reptiles are oviparous, with the developing embryos relying on the contents of the yolk to sustain development until hatching (lecithotrophy). The yolk is composed primarily of lipid and protein, which act as an energy source and the essential components to build embryonic tissue. Nevertheless, yolk and the resulting embryos contain many other nutrients, including inorganic ions, vitamins, carotenoids, water and hormones. Apart from water and oxygen, which may be taken up by eggs, and some inorganic ions that can come from the eggshell or even from outside the egg, everything required by the embryo must be in the egg when it is laid. Approximately 20% of squamate reptiles are viviparous, exhibiting a variety of placental complexities. Species with complex placentae have reduced yolk volumes, with the mother augmenting embryonic nutrition by provision across the placenta (placentotrophy). Despite assumed advantages of placentotrophy, only 5 out of approximately 100 lineages of viviparous squamates exhibit substantial placentotrophy. This paper reviews available and recent information on the yolk contents of a variety of squamate reptiles to ask the question, how are nutrients transported from the yolk to the embryo or across the placenta? Although, current available data suggest that, in broad terms, yolk is taken up by embryos without discrimination of the nutrients, there are some apparent exceptions, including the very long chain polyunsaturated fatty acids. In addition, fundamental differences in the patterns of energy utilisation in lizards and snakes suggest fundamental differences in lipid profiles in these taxa, which appear to reflect the differences between placentotrophic and lecithotrophic viviparous lizards.
Descriptors: reptiles, embryonic reptiles, energy, nutient, utilisation, yolk contents, placenta, nutrients, transport.

Thompson, M.B., S.M. Adams, J.F. Hebert, J.M. Biazik, and C.R. Murphy (2005). Placental function in lizards. In: Animals and environments: Proceedings of the Third International Conference of Comparative Physiology and Biochemistry,August 7, 2004-August 13, 2004, KwaZulu-Natal, South Africa, International Congress Series, 0531-5131, Elsevier: Amsterdam, p. 218-225. ISBN: 0444517634.
NAL Call Number: QP82 .I58 2004
Descriptors: reptiles, lizards, placental function, reproduction.

Thomson, M., J.F. Herbert, and M.B. Thompson (2006). Tyrosine phosphorylated proteins in the reproductive tract of the viviparous lizard Eulamprus tympanum and the oviparous lizard Lampropholis guichenoti. Comparative Biochemistry and Physiology. Part B, Biochemistry and Molecular Biology 144(3): 382-386. ISSN: 1096-4959.
Abstract: Plastic changes occur in the morphology of the uterus at various stages of the reproductive cycle in both oviparous and viviparous lizards and these may be influenced by estrogen. Estrogen driven phosphorylation of effector proteins on tyrosine residues plays a major role in the plastic modulation of uterine anatomy and physiology in vertebrates. We used electrophoresis and Western blotting to characterize the phosphotyrosine protein profiles at various stages of the reproductive pathway in an oviparous lizard Lampropholis guichenoti and a viviparous lizard Eulamprus tympanum. L. guichenoti displayed major bands in the 200-35 kDa range and a triplet of bands of molecular masses 61 kDa, 52 kDa and 48 kDa in 50% of specimens and a 38 kDa band in all specimens. In contrast, E. tympanum samples all displayed a single major band at 40 kDa, which was significantly elevated at the early pregnancy stage. Somewhat paradoxically, the viviparous species, which has the more complex uterine epithelial changes during pregnancy, has the fewest phosphotyrosine bands, so how tyrosine phosphorylation is affected during the evolution of viviparity is not clear.
Descriptors: reptiles, viviparous lizard, Eulamprus tympanum, oviparous lizard, Lampropholis guichenoti, reproductive tract, tyrosine phosphorylated proteins, reproductive cycle.

Tourmente, M., G.A. Cardozo, H.A. Guidobaldi, L.C. Giojalas, M. Bertona, and M. Chiaraviglio (2007). Sperm motility parameters to evaluate the seminal quality of Boa constrictor occidentalis, a threatened snake species. Research in Veterinary Science 82(1): 93-98. ISSN: 0034-5288.
Abstract: Semen quality analysis constitutes a powerful tool to evaluate the fertility potential of males in threatened species. The Argentine boa constrictor or lampalagua (Boa constrictor occidentalis) is a threatened snake species and has been included in Appendix I of CITES. The objective of this work is to characterize the sperm of B. c. occidentalis on the bases of dynamic parameters to improve this species conservation. Dynamic parameters were measured in sperm samples using videomicroscopy and image analysis software. The sperm population showed a high degree of heterogeneity in velocity parameter values and 95% of the cells showed a linear pattern of movement. Studies in other species indicate that the number of motile spermatozoa and their movement speed is directly correlated with fertilization success. This work will help to establish basic parameter values for the evaluation of the reproductive potential of populations of B. c. occidentalis and to resolve questions referred to its reproductive strategies.
Descriptors: reptiles, snake, Boa constictor occidentalis, sperm motility parameters, seminal quality, motile spermatazoa.

Uribe Aranzabal, M.C., A. Hernandez Franyutti, and L.J.J. Guillette (2006). Interembryonic regions of the uterus of the viviparous lizard Mabuya brachypoda (Squamata: Scincidae). Journal of Morphology 267(4): 404-414. ISSN: 0362-2525.
Abstract: Analysis of the structure and physiology of the uterine incubation chambers of viviparous squamates has provided insight concerning adaptations for gestation. However, the literature addressing the biology of the interembryonic regions of the uterus is very limited, presumably because it has been assumed that this area has little role in the development and support of embryos in viviparous squamates. This study was undertaken to examine the histology of the interembryonic regions of Mabuya brachypoda, a viviparous lizard with microlecithal ova and consequently substantial matrotrophic activity. The incubation chambers are oval, distended zones of the uterus, adjacent to the interembryonic regions. The wall of the interembryonic regions includes: mucosa, formed by a cuboidal or columnar epithelium with ciliated and nonciliated cells, and a lamina propria of vascularized connective tissue containing abundant acinar glands; myometrial smooth muscle consisting of inner circular and outer longitudinal layers; and serosa. The segment of the interembryonic region adjacent to the incubation chamber forms a transitional segment that displays folds of the mucosa that protrude into the uterine lumen. The limit of the incubation chamber is well defined by the long mucosal folds of the transitional segment. Long and thin extensions of extraembryonic membranes are present in the lumen of the transitional segment, outside of the incubation chamber region. The presence of abundant uterine glands and extraembryonic membranes in the interembryonic regions during gestation suggests uterine secretory activity and histotrophic transfer of nutrients to embryos in these regions.
Descriptors: lizards anatomy, histology, uterus anatomy, histology, viviparity, nonmammalian, embryo, lizards embryology, oviducts anatomy, histology.

Vercken, E., M. Massot, B. Sinervo, and J. Clobert (2007). Colour variation and alternative reproductive strategies in females of the common lizard Lacerta vivipara. Journal of Evolutionary Biology 20(1): 221-232. ISSN: 1010-061X.
Abstract: Within-sex colour variation is a widespread phenomenon in animals that often plays a role in social selection. In males, colour variation is typically associated with the existence of alternative reproductive strategies. Despite ecological conditions theoretically favourable to the emergence of such alternative strategies in females, the social significance of colour variation in females has less commonly been addressed, relative to the attention given to male strategies. In a population of the common lizard, females display three classes of ventral colouration: pale yellow, orange and mixed. These ventral colours are stable through individual's life and maternally heritable. Females of different ventral colourations displayed different responses of clutch size, clutch hatching success and clutch sex-ratio to several individual and environmental parameters. Such reaction patterns might reflect alternative reproductive strategies in females. Spatial heterogeneity and presence of density- and frequency-dependent feedbacks in the environment could allow for the emergence of such alternative strategies in this population and the maintenance of colour variation in females.
Descriptors: reptiles, common lizard, Lacerta vivipara, color variation, females, reproductive strategies.

Vieira, G.H., G.R. Colli, and S.N. Bao (2004). The ultrastructure of the spermatozoon of the lizard Iguana iguana (Reptilia, Squamata, Iguanidae) and the variability of sperm morphology among iguanian lizards. Journal of Anatomy 204(6): 451-464. ISSN: 0021-8782.
Abstract: The spermatozoon of Iguana iguana is filiform and resembles that of other iguanian lizards, being most similar to Tropidurus. All sperm synapomorphies of Tetrapoda, Amniota and Squamata are present in the sperm of Iguana iguana. By reconstructing the evolution of 30 sperm characters we identified a novel synapomorphy of Iguania: the presence of a well-developed acrosomal ridge at the level of the epinuclear lucent zone. Because of the poor topological resolution among iguanian clades we could not discount the possibility of convergence or neutral selection as determinant of the variability in characteristics of the sperm cell. In agreement with previous studies, we identified heterogeneous rates of evolution among the three main regions of the sperm cell, namely the head, midpiece and tail.
Descriptors: reptiles, lizard, Iguana iguana, spermatozoon, ultrastructure, sperm morphology, variability.

Villagran, M., F.R. Mendez, and J.R. Stewart (2005). Placentation in the Mexican lizard Sceloporus mucronatus (Squamata: Phrynosomatidae). Journal of Morphology 264(3): 286-297. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Abstract: We used light microscopy to study placental structure of the lizard Sceloporus mucronatus throughout 6 months of embryonic development. Three stages of placental development could be assigned to embryos based on the arrangement of the extraembryonic membranes. A highly vascular choriovitelline placenta was present in the embryonic hemisphere and a nonvascular bilaminar omphalopleure covered most of the abembryonic hemisphere of the egg during embryonic Stages 10-28. A chorioallantoic placenta replaced the choriovitelline placenta by embryonic Stage 29 and an omphaloplacenta covered the abembryonic hemisphere at this stage. The combination of these two placental types occurred in Stage 29-36 embryos. The final stage of placentation, embryonic Stages 37-40, was characterized by an omphalallantoic placenta in the abembryonic hemisphere and a chorioallantoic placenta in the embryonic hemisphere of the egg. The choriovitelline and chorioallantoic placentae are well vascularized, with closely apposed maternal and embryonic blood vessels. These structures are the most likely sites of respiratory exchange. In contrast, the omphaloplacenta and omphalallantoic placentae contain cuboidal or columnar epithelia and these structures may function in histotrophic exchange. Placentation of S. mucronatus is similar to that of predominantly lecithotrophic species in other squamate lineages suggesting that the evolution of this placental morphology is a response to similar factors and is independent of phylogeny.
Descriptors: lizards, Sceloporus mucronatus, anatomy, histology, growth, development, placenta anatomy, histology, placenta growth, development, embryo nonmammalian anatomy, histology, physiology, placenta physiology.

Visser, J. (2005). Ervaringen met de kweek van Iguana iguana. [Some notes on breeding Iguana iguana.]. Lacerta 63(5): 199-204. ISSN: 0023-7051.
Descriptors: reptiles, Iguana iguana, notes on breeding, diet, housing, temperature.
Language of Text: Dutch; Summary in English.

Vladimirova, I.G., T.A. Alekseeva, and M.V. Nechaeva (2005). [Growth and oxygen consumption in embryonic and early postembryonic development of European pond turtle Emys orbicularis (Reptilia: Emydidae)]. Izvestiia Akademii Nauk. Seriia Biologicheskaia Rossiiskaia Akademiia Nauk(2): 214-220. ISSN: 1026-3470.
Abstract: Experiments on developing eggs of European pond turtle (Emys orbicularis) demonstrated S-shaped changes in the rate of oxygen consumption and body weight during embryonic development. The rate of oxygen consumption and weight progressively increased within 70 days after hatching. During embryogenesis, the rate of oxygen consumption decreased. After hatching, it increased but then decreased to a certain level, which remained constant to the end of the studied period. We observed unidirectional changes in oxygen consumption rate during embryonic period and this pattern was maintained after hatching as well. The coefficients of the allometric relationship between oxygen consumption and body weight were a = 0.33 and k = 0.52 during the embryonic period and a = 0.17 and k = 0.89 during the postembryonic period.
Descriptors: European pond turtle, Emys orbicularis, oxygen consumption, embryology, growth, development, metabolism, developing eggs, embryogenesis.
Language of Text: Russian.

Wallace, B.P., P.R. Sotherland, P. Santidrian Tomillo, R.D. Reina, J.R. Spotila, and F.V. Paladino (2007). Maternal investment in reproduction and its consequences in leatherback turtles. Oecologia 152(1): 37-47. ISSN: print: 0029-8549; online: 1432-1939.
NAL Call Number: QL750.O3
Abstract: Maternal investment in reproduction by oviparous non-avian reptiles is usually limited to pre-ovipositional allocations to the number and size of eggs and clutches, thus making these species good subjects for testing hypotheses of reproductive optimality models. Because leatherback turtles (Dermochelys coriacea) stand out among oviparous amniotes by having the highest clutch frequency and producing the largest mass of eggs per reproductive season, we quantified maternal investment of 146 female leatherbacks over four nesting seasons (2001-2004) and found high inter- and intra-female variation in several reproductive characteristics. Estimated clutch frequency [coefficient of variation (CV) = 31%] and clutch size (CV = 26%) varied more among females than did egg mass (CV = 9%) and hatchling mass (CV = 7%). Moreover, clutch size had an approximately threefold higher effect on clutch mass than did egg mass. These results generally support predictions of reproductive optimality models in which species that lay several, large clutches per reproductive season should exhibit low variation in egg size and instead maximize egg number (clutch frequency and/or size). The number of hatchlings emerging per nest was positively correlated with clutch size, but fraction of eggs in a clutch yielding hatchlings (emergence success) was not correlated with clutch size and varied highly among females. In addition, seasonal fecundity and seasonal hatchling production increased with the frequency and the size of clutches (in order of effect size). Our results demonstrate that female leatherbacks exhibit high phenotypic variation in reproductive traits, possibly in response to environmental variability and/or resulting from genotypic variability within the population. Furthermore, high seasonal and lifetime fecundity of leatherbacks probably reflect compensation for high and unpredictable mortality during early life history stages in this species.
Descriptors: reptiles, leatherback turtles, Dermochelys coriacea, maternal investment, reproduction, consquences.

Wang, R.P. and T.S. Xia (2005). Reproduction of Alligator sinensis after artificial wintering. Chinese Journal of Zoology 40(4): 92-95. ISSN: 0250-3263.
Descriptors: reptiles, reproduction, Alligator sinensis, artificial wintering, breeding success.
Language of Text: Chinese; English.

Wapstra, E., M. Olsson, R. Shine, A. Edwards, R. Swain, and J.M. Joss (2004). Maternal basking behaviour determines offspring sex in a viviparous reptile. Proceedings of the Royal Society of London. Series B, Biological Sciences 271(Suppl. 4): S230-S232. ISSN: 0080-4649.
Abstract: Two primary dichotomies within vertebrate life histories involve reproductive mode (oviparity versus viviparity) and sex determination (genotypic sex determination versus environmental sex determination). Although reptiles show multiple evolutionary transitions in both parameters, the co-occurrence of viviparity and environmental-dependent sex determination have heretofore been regarded as incompatible. Our studies on the viviparous lizard Niveoscincus ocellatus show that the extent of basking by a female influences the sex of her offspring. Critically, our data reveal this effect both in the field (via correlations between date of birth and litter sex ratio) and in a laboratory experiment (females with reduced basking opportunities produced more male offspring). Changes in thermoregulatory behaviour thus allow pregnant female lizards to modify the sex of their offspring.
Descriptors: reptiles, viviparous lizard, Niveoscincus ocellatus, maternal basking, offspring sex, sex determination, thermoregulatory behavior.

Warner, D.A., M.B. Lovern, and R. Shine (2007). Maternal nutrition affects reproductive output and sex allocation in a lizard with environmental sex determination. Proceedings of the Royal Society of London. Series B, Biological Sciences 274(1611): 883-890. ISSN: 0080-4649.
Abstract: Life-history traits such as offspring size, number and sex ratio are affected by maternal feeding rates in many kinds of animals, but the consequences of variation in maternal diet quality (rather than quantity) are poorly understood. We manipulated dietary quality of reproducing female lizards (Amphibolurus muricatus; Agamidae), a species with temperature-dependent sex determination, to examine strategies of reproductive allocation. Females maintained on a poor-quality diet produced fewer clutches but massively (twofold) larger eggs with lower concentrations of yolk testosterone than did conspecific females given a high-quality diet. Although all eggs were incubated at the same temperature, and yolk steroid hormone levels were not correlated with offspring sex, the nutrient-deprived females produced highly male-biased sex ratios among their offspring. These responses to maternal nutrition generate a link between sex and offspring size, in a direction likely to enhance maternal fitness if large body size enhances reproductive success more in sons than in daughters (as seems plausible, given the mating system of this species). Overall, our results show that sex determination in these animals is more complex, and responsive to a wider range of environmental cues, than that suggested by the classification of 'environmental sex determination'.
Descriptors: reptiles, female lizards, Amphibolurus muricatus, maternal nutrition, repoductive output, sex allocation, affects, sex determination.

Warner, D.A. and R. Shine (2005). The adaptive significance of temperature-dependent sex determination: experimental tests with a short-lived lizard. Evolution International Journal of Organic Evolution 59(10): 2209-2221. ISSN: print: 0014-3820; online: 1558-5646 .
NAL Call Number: 443.8 Ev62
Abstract: Why is the sex of many reptiles determined by the temperatures that these animals experience during embryogenesis, rather than by their genes? The Charnov-Bull model suggests that temperature-dependent sex determination (TSD) can enhance maternal fitness relative to genotypic sex determination (GSD) if offspring traits affect fitness differently for sons versus daughters and nest temperatures either determine or predict those offspring traits. Although potential pathways for such effects have attracted much speculation, empirical tests largely have been precluded by logistical constraints (i.e., long life spans and late maturation of most TSD reptiles). We experimentally tested four differential fitness models within the Charnov-Bull framework, using a short-lived, early-maturing Australian lizard (Amphibolurus muricatus) with TSD. Eggs from wild-caught females were incubated at a range of thermal regimes, and the resultant hatchlings raised in large outdoor enclosures. We applied an aromatase inhibitor to half the eggs to override thermal effects on sex determination, thus decoupling sex and incubation temperature. Based on relationships between incubation temperatures, hatching dates, morphology, growth, and survival of hatchlings in their first season, we were able to reject three of the four differential fitness models. First, matching offspring sex to egg size was not plausible because the relationship between egg (offspring) size and fitness was similar in the two sexes. Second, sex differences in optimal incubation temperatures were not evident, because (1) although incubation temperature influenced offspring phenotypes and growth, it did so in similar ways in sons versus daughters, and (2) the relationship between phenotypic traits and fitness was similar in the two sexes, at least during preadult life. We were unable to reject a fourth model, in which TSD enhances offspring fitness by generating seasonal shifts in offspring sex ratio: that is, TSD allows overproduction of daughters (the sex likely to benefit most from early hatching) early in the nesting season. In keeping with this model, hatching early in the season massively enhanced body size at the beginning of the first winter, albeit with a significant decline in probability of survival. Thus, the timing of hatching is likely to influence reproductive success in this short-lived, early maturing species; and this effect may well differ between the sexes.
Descriptors: Australian lizard, Amphibolurus muricatus, physiological, embryology, sex ratio, temperature, embryo, physiology, embryonic development, growth, development, reproduction, sex determination, genetics.

Warner, D.A. and R. Shine (2007). Reproducing lizards modify sex allocation in response to operational sex ratios. Biology Letters 3(1): 47-50. ISSN: 1689-1392.
Abstract: Sex-allocation theory suggests that selection may favour maternal skewing of offspring sex ratios if the fitness return from producing a son differs from that for producing a daughter. The operational sex ratio (OSR) may provide information about this potential fitness differential. Previous studies have reached conflicting conclusions about whether or not OSR influences sex allocation in viviparous lizards. Our experimental trials with oviparous lizards (Amphibolurus muricatus) showed that OSR influenced offspring sex ratios, but in a direction opposite to that predicted by theory: females kept in male-biased enclosures overproduced sons rather than daughters (i.e. overproduced the more abundant sex). This response may enhance fitness if local OSRs predict survival probabilities of offspring of each sex, rather than the intensity of sexual competition.
Descriptors: reptiles, oviparous lizards, Amphibolurus muricatus, sex allocation, sex ratios, reproducing, maternal skewing.

Weiss, S.L., D.H. Jennings, and M.C. Moore (2002). Effect of captivity in semi-natural enclosures on the reproductive endocrinology of female lizards. General and Comparative Endocrinology 128(3): 238-246. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Descriptors: reptiles, female lizards, reproductive endocrinology, effect of captivity, semi natural enclosures.

Weiss, S.L., G. Johnston, and M.C. Moore (2007). Corticosterone stimulates hatching of late-term tree lizard embryos. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 146(3): 360-365. ISSN: 1095-6433.
Abstract: The regulation of hatching in oviparous animals is important for successful reproduction and survival, but is poorly understood. We unexpectedly found that RU-486, a progesterone and glucocorticoid antagonist, interferes with hatching of viable tree lizard (Urosaurus ornatus) embryos in a dose-dependent manner and hypothesized that embryonic glucocorticoids regulate hatching. To test this hypothesis, we treated eggs with corticosterone (CORT) or vehicle on Day 30 (85%) of incubation, left other eggs untreated, and observed relative hatch order and hatch time. In one study, the CORT egg hatched first in 9 of 11 clutches. In a second study, the CORT egg hatched first in 9 of 12 clutches, before vehicle-treated eggs in 10 of 12 clutches, and before untreated eggs in 7 of 9 clutches. On average, CORT eggs hatched 18.2 h before vehicle-treated eggs and 11.6 h before untreated eggs. Thus, CORT accelerates hatching of near-term embryos and RU-486 appears to block this effect. CORT may mobilize energy substrates that fuel hatching and/or accelerate lung development, and may provide a mechanism by which stressed embryos escape environmental stressors.
Descriptors: reptiles, tree lizard, Urosaurus ornatus, corticosterone stimulates hatching, late term embryos, regulation of hatching, progesterone, glucocorticoid.

Whitaker, N. (2006). Immaculate conception, incubation protocols, and egg characteristics of the Ganges softshell turtle (Aspideretes gangeticus). Contemporary Herpetology 2006(1): 1-6. ISSN: 1094-2246.
Descriptors: reptiles, softshell turtle, Aspideretes gangeticus, incubation protocols, egg characteristics, reproductive biology, research.

Wilkinson, L.R. and J. Whitfield Gibbons (2005). Patterns of reproductive allocation: clutch and egg size variation in three freshwater turtles. Copeia 2005(4): 868-879. ISSN: 0045-8511.
Descriptors: reptiles, freshwater turtles, reproductive allocation, patterns, clutch size, egg size, variation.

Willingham, E.J. (2005). The effects of atrazine and temperature on turtle hatchling size and sex ratios. Frontiers in Ecology and the Environment 3(6): 309-313. ISSN: 1540-9295.
NAL Call Number: QL540.F76
Descriptors: reptiles, atrazine, temperature, effects, turtle hatchling size, sex ratios, reproduction, tocixity.

Woodley, S.K. and M.C. Moore (2002). Plasma corticosterone response to an acute stressor varies according to reproductive condition in female tree lizards (Urosaurus ornatus). General and Comparative Endocrinology 128(2): 143-148. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: The magnitude of the glucocorticoid response to a stressor can depend on both environmental and physiological context. One factor that has not been examined is whether females of different reproductive states have different responses to a stressor. We examined whether corticosterone (CORT) increased after a 10 min handling stress in oviparous female tree lizards (Urosaurus ornatus) that were vitellogenic (yolking follicles) or gravid (post-ovulatory). We found that stressed vitellogenic females had a large increase in plasma CORT whereas gravid females did not. Baseline levels of CORT in gravid females were relatively high and similar to those in stressed vitellogenic females. The lack of a stress response in gravid females may be due to an inability to secrete higher levels of CORT or a suppression of the stress response. In addition, within vitellogenic females, CORT was positively correlated with ovarian weight, suggesting that CORT may function in some aspect of ovarian development during vitellogenesis.
Descriptors: reptiles, female tree lizards, Urosaurus ornatus, plasma corticosterone response, acute stressor, reproductive condition.

Woolley, S.C., J.T. Sakata, and D. Crews (2004). Evolutionary insights into the regulation of courtship behavior in male amphibians and reptiles. Physiology and Behavior 83(2): 347-360. ISSN: 0031-9384.
Abstract: Comparative studies of species differences and similarities in the regulation of courtship behavior afford an understanding of evolutionary pressures and constraints shaping reproductive processes and the relative contributions of hormonal, genetic, and ecological factors. Here, we review species differences and similarities in the control of courtship and copulatory behaviors in male amphibians and reptiles, focusing on the role of sex steroid hormones, the neurohormone arginine vasotocin (AVT), and catecholamines. We discuss species differences in the sensory modalities used during courtship and in the neural correlates of these differences, as well as the value of particular model systems for neural evolution studies with regard to reproductive processes. For example, in some genera of amphibians (e.g., Ambystoma) and reptiles (e.g., Cnemidophorus), interspecific hybridizations occur, making it possible to compare the ancestral with the descendant species, and these systems provide a window into the process of behavioral and neural evolution as well as the effect of genome size. Though our understanding of the hormonal and neural correlates of mating behavior in a variety of amphibian and reptilian species has advanced substantially, more studies that manipulate hormone or neurotransmitter systems are required to assess the functions of these systems.
Descriptors: amphibians, reptiles, courtship behavior, male, hormonal, genetic, species differences, copulatory behaviors.

Wright, K. (2005). Reducing the incidence of reproductive problems in snakes and lizards. Exotic DVM 7(3): 58-62. ISSN: 1521-1363.
NAL Call Number: SF981.E96
Descriptors: reptiles, snakes, lizards, reproductive problems, reducing the incidence.

Xia, T.S. and X.Q. Jiang (2005). Effect of environmental factors on nesting and laying eggs of Chinese alligator in captivity. Sichuan Journal of Zoology 24(3): 373-377. ISSN: 1000-7083.
Descriptors: reptiles, Chinese alligator, Alligator sinensis, enviromental factors, effect, nesting, egg laying in captivity.
Language of Text: Chinese; Summary in Chinese and English.

Xia, T.S., K.H. Zhou, and J.L. Zhu (2006). Influence of hibernant temperature on reproduction of Chinese alligator. Sichuan Journal of Zoology 25(2): 398-399. ISSN: 1000-7083.
Descriptors: reptiles, Chinese alligator, hibernant temperature, reproduction, influence.
Language of Text: Chinese; Summary in Chinese and English.

Yajurvedi, H.N. and S. Menon (2005). Influence of stress on gonadotrophin induced testicular recrudescence in the lizard Mabuya Carinata. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 303(7): 534-540. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Abstract: Administration (ip) of FSH (10 IU/0.1 ml distilled water (dw)/lizard/alternate days/30 days) to adult male lizards, Mabuya carinata, during the early recrudescence phase of the reproductive cycle caused activation of spermatogenic and steroidogenic activity of the testis, as shown by a significant increase in mean number of spermatogonia, primary spermatocytes and spermatids, and serum levels of testosterone, as compared to initial controls. In addition, there were abundant spermatozoa in the lumen of the seminiferous tubules. Interestingly, administration of a similar dosage of FSH to lizards exposed to stressors (handling, chasing, and noise randomly applied, five times a day for 30 days) resulted in a significant increase in mean number of spermatogonia and primary spermatocytes over initial control values, whereas the number of secondary spermatocytes and spermatids and serum levels of testosterone did not significantly differ from those of initial controls, and were significantly lower than FSH treated normal lizards. Further, spermatozoa were infrequently found in the seminiferous tubules of these lizards. Treatment controls (receiving 0.1 ml dw/lizard/alternate days for 30 days) did not show significant variation in mean number of spermatogonia, spermatocytes and spermatids, and serum levels of testosterone from initial controls. Another group of lizards was exposed to stressors and did not receive FSH. These lizards showed a significant decrease in mean number of secondary spermatocytes compared to treatment controls and all other parameters did not significantly differ from those of both control groups. The results reveal that gonadotrophin-induced spermatogonial proliferation occurs under stressful conditions, whereas progress of spermatogenesis beyond primary spermatocyte stage is impaired due to inhibition (under stress) of gonadotrophin induced steroidogenic activity in M. carinata.
Descriptors: lizard, Mabuya carinata, stress, influence, gonadotrophin, induced testicular recrudescence, reproductive cycle, distilled water, testosterone, serum levels.

Zhang, F., X.b. Wu, W.z. Meng, and J.l. Zhu (2006). Ecology on the making nest and laying eggs of Chinese alligator (Alligator sinensis) under artificial feeding conditions. Zoological Research 27(2): 151-156. ISSN: 0254-5853.
NAL Call Number: QL1.T85
Descriptors: reptiles, Chinese alligator, Alligatoe sinensis, making nest, laying eggs, artificial feeding conditions, ecology, behavior.
Language of Text: Chinese; Summary in Chinese and English.

Zhang, X.D., X. Ji, L.G. Luo, J.F. Gao, and L. Zhang (2005). Sexual dimorphism and female reproduction in the Qinghai toadheaded lizard Phrynocephalus vlangalii. Acta Zoologica Sinica 51(6): 1006-1012. ISSN: 0001-7302.
Descriptors: reptiles, Qinghai toadheaded lizard, Phrynocephalus vlangalii, sexual dimorphism, female, reproduction.
Language of Text: Chinese; English.

Zhang, Y.p., X.p. Ying, and X. Ji (2005). Ultrastructure of the spermatozoon of the northern grass lizard (Takydromus septentrionalis) with comments on the variability of sperm morphology among lizard taxa. Zoological Research 26(5): 518-526. ISSN: 0254-5853.
NAL Call Number: QL1.T85
Descriptors: reptiles, northern grass lizard, Takydromus septentrionalis, spermatozoon, ultrastructure, sperm mprphology, variability, comments.
Language of Text: Chinese; Summary in Chinese and English.

Zhu, X.P., Y.L. Chen, C.Q. Wei, Y.H. Liu, and J.F. Giu (2006). Temperature effects on sex determination in yellow pond turtle (Mauremys mutica Cantor). Acta Ecologica Sinica 26(2): 620-625. ISSN: 1000-0933.
Descriptors: reptiles, yellow pond turtle, Mauremys mutica, temperature effects, sex determination.
Language of Text: Chinese; Summary in Chinese and English.

Ziegler, T. and S. Olbort (2004). Genitalstrukturen und Geschlechtsunterscheidung bei Krokodilen. [Genitalia structures and sex differentiation in crocodiles.]. Draco 5(4): 39-47 Nr 20. ISSN: 1439-8168.
Descriptors: reptiles, crocodiles, sex differentiation, genitalia structures, genital differences.
Language of Text: German.



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