Diet, Nutrition and Metabolism

Akani, G.C., E.A. Eniang, I.J. Ekpo, F.M. Angelici, and L. Luiselli (2003). Food habits of the snake Psammophis phillipsi from the continuous rain-forest region of southern nigeria (west africa). Journal of Herpetology 37(1): 208-211. ISSN: 0022-1511.
NAL Call Number: QL640.J6
Descriptors: reptiles, snake, Psammophis phillipsi, food habits, rain forest region, lizards, small mammals, southern Nigeria.

Andrade, D.V., A.P. Cruz Neto, A.S. Abe and T. Wang (2005). Specific dynamic action in ectothermic vertebrates: A review of determinants of postprandial metabolic response in fishes, amphibians, and reptiles. In: J.M.W.T. Starck (Editors), Physiological and Ecological Adaptations to Feeding in Vertebrates., Science Publishers, Inc.: Enfield, NH, p. 305-324. ISBN: 1578082463.
NAL Call Number: QP145 .P46 2005
Descriptors: amphibians, fish, reptiles, determinants of postprandial metabolic response, digestion.

Angilletta, M.J.J., V. Lee, and A.C. Silva (2006). Energetics of lizard embryos are not canalized by thermal acclimation. Physiological and Biochemical Zoology 79(3): 573-580. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: In some species of ectotherms, temperature has little or no effect on the amount of energy expended during embryonic development. This phenomenon can result from either of two mechanisms: (1) a shorter incubation period at higher temperatures, which offsets the expected increase in metabolic rate, or (2) a compensatory decrease in the rate at which embryos expend energy for maintenance. To distinguish the relative importance of these two mechanisms, we quantified the acute and chronic effects of temperature on embryonic metabolism in the eastern fence lizard (Sceloporus undulatus). First, we measured metabolic rates of individual embryos at 27 degrees, 31 degrees, and 34 degrees C. Second, we examined the capacity for thermal acclimation by measuring the metabolic rates of embryos at 30 degrees C, after a period of incubation at either 28 degrees or 32 degrees C. As with adult reptiles, the metabolic rates of embryos increased with an acute increase in temperature; the Q(10) of metabolic rate from 27 degrees to 34 degrees C was 2.1 (+/-0.2). No evidence of thermal acclimation was observed either early or late in development. In S. undulatus, a shorter incubation period at higher temperatures appears to play the primary role in canalizing the energy budget of an embryo, but a reduction in the cost of growth could play a secondary role.
Descriptors: lizards, acclimatization physiology, embryonic development physiology, lizards embryology, lizards physiology, basal metabolism physiology, embryo, non-mammalian physiology, oviparity physiology, temperature.

Birkedal, R. and H. Gesser (2004). Effects of hibernation on mitochondrial regulation and metabolic capacities in myocardium of painted turtle (Chrysemys picta). Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 139(3): 285-291. ISSN: 1095-6433.
Abstract: Painted turtles hibernating during winter may endure long-term exposure to low temperature and anoxia. These two conditions may affect the aerobic capacity of a tissue and might be of particular importance to the cardiac muscle normally highly reliant on aerobic energy production. The present study addressed how hibernation affects respiratory characteristics of mitochondria in situ and the metabolic pattern of turtle myocardium. Painted turtles were acclimated to control (25 degrees C), cold (5 degrees C) normoxic and cold anoxic conditions. In saponin-skinned myocardial fibres, cold acclimation increased mitochondrial respiratory capacity and decreased apparent ADP-affinity. Concomitant anoxia did not affect this. Creatine increased the apparent ADP-affinity to similar values in the three acclimation groups, suggesting a functional coupling of creatine kinase to mitochondrial respiration. As to the metabolic pattern, cold acclimation decreased glycolytic capacity in terms of pyruvate kinase activity and increased lactate dehydrogenase (LHD) activity. Concomitant anoxia counteracted the cold-induced decrease in pyruvate kinase activity and increased creatine kinase activity. In conclusion, cold acclimation seems to increase aerobic and decrease anaerobic energy production capacity in painted turtle myocardium. Importantly, anoxia does not affect the mitochondrial functional integrity but seems to increase the capacity for anaerobic energy production and energy buffering.
Descriptors: reeptiles, painted turtle, hibernation, effects, metabolic capacities, myocardium, mitochondrial regulation, anoxia, low temperature.

Bouchard, S.S. and K.A. Bjorndal (2006). Ontogenetic diet shifts and digestive constraints in the omnivorous freshwater turtle Trachemys scripta. Physiological and Biochemical Zoology 79(1): 150-158. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Many reptiles undergo an ontogenetic diet shift from carnivory to herbivory. In this study, we used the yellow-bellied slider turtle, Trachemys scripta, as a model to evaluate whether juvenile turtles are carnivorous because physiological constraints preclude herbivory. We conducted feeding trials in which we fed juvenile and adult turtles a duckweed plant, Lemna valdiviana, or a freshwater grass shrimp, Palaemontes paludosus, for 5 wk. During the trials, we measured mass-specific intake, digestibility, and digestible intake for both size classes, as well as juvenile growth. At the end of the trials, we measured the nutrient composition of the juvenile turtles. Juveniles fed shrimp grew 3.2 times faster than those fed duckweed and had equivalent lipid stores. Digestive processing in juveniles was extremely efficient on the shrimp diet, with higher mass-specific intakes than adults and very high digestibilities (97%). Juveniles digested duckweed as well as adults did; however, their intake of this diet was limited, possibly by the time required for fermentation. We concluded that although juveniles can process plant material, an animal diet allows for greater juvenile growth, which in turtles is linked to higher survivorship and increased future reproductive success.
Descriptors: juvenile slider turtles, diet, digestion physiology, feeding behavior physiology, turtles growth, development, physiology, gastrointestinal contents.

Bouchard, S.S. and K.A. Bjorndal (2006). Nonadditive interactions between animal and plant diet items in an omnivorous freshwater turtle Trachemys scripta. Comparative Biochemistry and Physiology. Part B, Biochemistry and Molecular Biology 144(1): 77-85. ISSN: 1096-4959.
Abstract: Nonadditive interactions occur when diet items interact with one another such that the net energy or nutrient gain from a mixed diet differs from that predicted by summing the gains from individual diet components. We quantified nonadditive effects between duckweed, Lemma valdiviana, and grass shrimp, Palaemontes paludosus, in the freshwater turtle Trachemys scripta. We fed turtles 100% duckweed, 100% shrimp, and two mixed diets containing 67% duckweed, 33% shrimp and 14% duckweed, 86% shrimp (dry matter basis). During each feeding trial, we measured intake, digestibility, and transit time of the diet, and upon conclusion, short-chain fatty acid concentrations in turtle digestive tracts. Digestibility was lower on the 67% duckweed diet, but higher on the 14% diet. These apparent nonadditive interactions may be due to differences in transit time of duckweed and shrimp. We believe this is the first evidence of two diet items producing opposing nonadditive effects when fed in different ratios.
Descriptors: freshwater turtle Trachemys scripta, diet, digestion physiology, feeding behavior, gastrointestinal transit, duckweed and grass shrimp physiology, Palaemonidae, plants, turtles physiology, eating gastrointestinal contents, nutritive value.

Bradshaw, C.J., C.R. McMahon, and G.C. Hays (2007). Behavioral inference of diving metabolic rate in free-ranging leatherback turtles. Physiological and Biochemical Zoology 80(2): 209-219. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Good estimates of metabolic rate in free-ranging animals are essential for understanding behavior, distribution, and abundance. For the critically endangered leatherback turtle (Dermochelys coriacea), one of the world's largest reptiles, there has been a long-standing debate over whether this species demonstrates any metabolic endothermy. In short, do leatherbacks have a purely ectothermic reptilian metabolic rate or one that is elevated as a result of regional endothermy? Recent measurements have provided the first estimates of field metabolic rate (FMR) in leatherback turtles using doubly labeled water; however, the technique is prohibitively expensive and logistically difficult and produces estimates that are highly variable across individuals in this species. We therefore examined dive duration and depth data collected for nine free-swimming leatherback turtles over long periods (up to 431 d) to infer aerobic dive limits (ADLs) based on the asymptotic increase in maximum dive duration with depth. From this index of ADL and the known mass-specific oxygen storage capacity (To(2)) of leatherbacks, we inferred diving metabolic rate (DMR) as To2/ADL. We predicted that if leatherbacks conform to the purely ectothermic reptilian model of oxygen consumption, these inferred estimates of DMR should fall between predicted and measured values of reptilian resting and field metabolic rates, as well as being substantially lower than the FMR predicted for an endotherm of equivalent mass. Indeed, our behaviorally derived DMR estimates (mean=0.73+/-0.11 mL O(2) min(-1) kg(-1)) were 3.00+/-0.54 times the resting metabolic rate measured in unrestrained leatherbacks and 0.50+/-0.08 times the average FMR for a reptile of equivalent mass. These DMRs were also nearly one order of magnitude lower than the FMR predicted for an endotherm of equivalent mass. Thus, our findings lend support to the notion that diving leatherback turtles are indeed ectothermic and do not demonstrate elevated metabolic rates that might be expected due to regional endothermy. Their capacity to have a warm body core even in cold water therefore seems to derive from their large size, heat exchangers, thermal inertia, and insulating fat layers and not from an elevated metabolic rate.
Descriptors: reptiles, leatherback turtles, diving metabolic rate, behavioral inference, metabolic rate, ectothermic, warm body core.

Britt, E.J., J.W. Hicks, and A.F. Bennett (2006). The energetic consequences of dietary specialization in populations of the garter snake, Thamnophis elegans. Journal of Experimental Biology 209(Pt 16): 3164-3169. ISSN: 0022-0949.
Online: http://dx.doi.org/10.1242/jeb.02366
NAL Call Number: 442.8 B77
Abstract: We investigated the intraspecific variation in digestive energetics between dietary specialist and generalist populations of the Western Terrestrial garter snake (Thamnophis elegans) in northern California. Coastal populations have a specialized diet of slugs and inland populations have a generalized diet of fish, anurans, mice and leeches. The difference in prey preference between the two populations is congenital, heritable and ontogenetically stable. To examine energetic specializations and trade-offs in these populations, we measured the net assimilation efficiency of each snake population on both slug (Ariolimax columbianus) and fish (Rhinichthys osculus) diets. The net assimilation efficiency was measured during digestion of a meal and continued until metabolic rate re-attained prefeeding levels. Coastal snakes were able to utilize 62% more of the ingested energy towards production from slug diets through both increased assimilation of nutrients and reduced digestive costs. For fish, assimilation and digestive costs were the same in both coastal and inland populations. These results support the hypothesis that snakes with specialized diets can evolve physiological traits to extract nutrients more efficiently. However, there was no apparent trade-off on the more generalized diet that was associated with this specialization.
Descriptors: Colubridae metabolism, diet, adaptation, physiological, Colubridae genetics, Colubridae physiology, cyprinidae, digestion physiology, energy metabolism, food preferences, gastropoda, nutritive value.

Chen, H.l., M.b. Ye, and R.j. Lin (2006). High density feeding of green turtle through hibernation. Sichuan Journal of Zoology 25(2): 395-397. ISSN: 1000-7083.
Descriptors: reptiles, Chelonia mydas, green turtle, rearing techniques, high density feeding, through hibernation, winter.
Language of Text: Chinese; Summary in Chinese and English.

Clark, T.D., P.J. Butler, and P.B. Frappell (2005). Digestive state influences the heart rate hysteresis and rates of heat exchange in the varanid lizard Varanus rosenbergi. Journal of Experimental Biology 208(Pt 12): 2269-2276. ISSN: 0022-0949.
Online: http://dx.doi.org/10.1242/jeb.01657
NAL Call Number: 442.8 B77
Abstract: To maximize the period where body temperature (Tb) exceeds ambient temperature (Ta), many reptiles have been reported to regulate heart rate (fH) and peripheral blood flow so that the rate of heat gain in a warming environment occurs more rapidly than the rate of heat loss in a cooling environment. It may be hypothesized that the rate of cooling, particularly at relatively cool Tbs, would be further reduced during postprandial periods when specific dynamic action (SDA) increases endogenous heat production (i.e. the heat increment of feeding). Furthermore, it may also be hypothesized that the increased perfusion of the gastrointestinal organs that occurs during digestion may limit peripheral blood flow and thus compromise the rate of heating. Finally, if the changes in fh are solely for the purpose of thermoregulation, there should be no associated changes in energy demand and, consequently, no hysteresis in the rate of oxygen consumption (V(O2)). To test these hypotheses, seven individual Varanus rosenbergi were heated and cooled between 19 degrees C and 35 degrees C following at least 8 days fasting and then approximately 25 h after consumption of a meal (mean 10% of fasted body mass). For a given Tb between the range of 19-35 degrees C, fh of fasting lizards was higher during heating than during cooling. Postprandial lizards also displayed a hysteresis in fh, although the magnitude was reduced in comparison with that of fasting lizards as a result of a higher fh during cooling in postprandial animals. Both for fasting and postprandial lizards, there was no hysteresis in V(O2) at any Tb throughout the range although, as a result of SDA, postprandial animals displayed a significantly higher V(O2) than fasting animals both during heating and during cooling at Tbs above 24 degrees C. The values of fh during heating at a given Tb were the same for fasting and postprandial animals, which, in combination with a slower rate of heating in postprandial animals, suggests that a prioritization of blood flow to the gastrointestinal organs during digestion is occurring at the expense of higher rates of heating. Additionally, postprandial lizards took longer to cool at Tbs below 23 degrees C, suggesting that the endogenous heat produced during digestion temporarily enhances thermoregulatory ability at lower temperatures, which would presumably assist V. rosenbergi during cooler periods in the natural environment by augmenting temperature-dependent physiological processes.
Descriptors: lizard, Varanus rosenbergi, body temperature regulation, digestive system, gastrointestinal tract, blood supply, heart rate, postprandial period, body temperature, electrocardiography, oxygen consumption.

Clusella Trullas, S., J.R. Spotila, and F.V. Paladino (2006). Energetics during hatchling dispersal of the olive ridley turtle Lepidochelys olivacea using doubly labeled water. Physiological and Biochemical Zoology 79(2): 389-399. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Studies of metabolism are central to the understanding of the ecology, behavior, and evolution of reptiles. This study focuses on one phase of the sea turtle life cycle, hatchling dispersal, and gives insight into energetic constraints that dispersal imposes on hatchlings. Hatchling dispersal is an energetically expensive phase in the life cycle of the olive ridley turtle Lepidochelys olivacea. Field metabolic rates (FMRs), determined using the doubly labeled water (DLW) method, for L. olivacea hatchlings digging out of their nest chamber, crawling at the sand surface, and swimming were five, four, and seven times, respectively, the resting metabolic rate (RMR). The cost of swimming was 1.5 and 1.8 times the cost of the digging and crawling phases, respectively, and we estimated that if L. olivacea hatchlings swim at frenzy levels, they can rely on yolk reserves to supply energy for only 3-6 d once they reach the ocean. We compared our RMR and FMR values by establishing an interspecific RMR mass-scaling relationship for a wide range of species in the order Testudines and found a scaling exponent of 1.06. This study demonstrates the feasibility of using the DLW method to estimate energetic costs of free-living sea turtle hatchlings and emphasizes the need for metabolic studies in various life-history stages.
Descriptors: olive ridley turtle Lepidochelys olivacea, newborn metabolism, energy metabolism physiology, turtles metabolism, water metabolism, body weight, deuterium, motor activity physiology, oxygen isotopes, species specificity.

Craig, M.D., P.C. Withers, and S.D. Bradshaw (2006). Patterns of diet and microhabitat use by four species of sympatric Ctenotus lizards: Do they reveal foraging specialisation? Journal of the Royal Society of Western Australia 89(1): 1-5. ISSN: 0035-922X.
NAL Call Number: 514 P432
Descriptors: reptiles, Ctenotus lizards, diet, microhabitat, patterns, foraging specialisation, foraging.

Donovan, E.R. and T.T. Gleeson (2006). Metabolic support of moderate activity differs from patterns seen after extreme behavior in the desert iguana Dipsosaurus dorsalis. Physiological and Biochemical Zoology 79(2): 370-388. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: This study examined glucose and lactate metabolism in an iguanid lizard, Dipsosaurus dorsalis, during rest and after activity patterned on field behavior (15 s of running at 1 m/s). Metabolite oxidation and incorporation into glycogen by the whole animal, the liver, and oxidative and glycolytic muscle fibers were measured using (14)C- and (13)C-labeled compounds. Results showed that lactate metabolism is more responsive to changes that occurred between rest and recovery, whereas glucose appears to play a more steady state role. After activity, lactate oxidation produced 57 times as much ATP during 1 h of recovery than did glucose oxidation. However, lactate oxidation rates were elevated for only 30 min after activity, while glucose oxidation remained elevated beyond 1 h. Lactate was the primary source for glycogen synthesis during recovery, and glucose was the main glycogenic substrate during rest. This study supports previous research showing that brief activity in D. dorsalis is primarily supported by glycolysis and phosphocreatine breakdown, but it also suggests that there may be less of a reliance on glycolysis and a greater reliance on phosphocreatine than previously shown. The findings presented here indicate that the metabolic consequences of the behaviorally relevant activity studied are less severe than has been suggested by studies using more extreme activity patterns.
Descriptors: desert iguana, Dipsosaurus dorsalis, behavior, physiology, desert climate, iguanas metabolism, adenosine triphosphate metabolism, glucose metabolism, glycogen blood, metabolism, lactic acid blood, metabolism, liver metabolism, motor activity, skeletal metabolism.

Elsey, R.M. (2006). Food habits of Macrochelys temminckii (alligator snapping turtle) from Arkansas and Louisiana. Southeastern Naturalist 5(3): 443-452. ISSN: 1528-7092.
NAL Call Number: 409.6 So8
Descriptors: reptiles, alligator snapping turtle, Macrochelys temminckii, food habits, stomach contents, intestinal contents, fish, crawfish, molluscs, turtles, variety.

Ferreira, B., M. Garcia, B.P. Jupp, and A. Al Kiyumi (2006). Diet of the green turtle (Chelonia mydas) at Ra's Al Hadd, Sultanate of Oman. Chelonian Conservation and Biology 5(1): 141-146. ISSN: 1071-8443.
Descriptors: reptiles, green turtle, Chelonia mydas, plants, diet, Oman.

Finke, M.D. (2003). Gut loading to enhance the nutrient content of insects as food for reptiles: a mathematical approach. Zoo Biology 22(2): 147-162. ISSN: 0733-3188.
NAL Call Number: QL77.5.Z6
Descriptors: reptiles, zoo animals, animal feeding, Acheta domesticus, Tenebrio molitor, Bombyx mori, gut loading, insects, nutrient content, insects as food, nutritive value.

Fledelius, B. and B. Bruun (2004). Vitaminers og mineralers betydning for vores krybdyr. [The importance of vitamins and minerals for the reptiles we keep.]. Nordisk Herpetologisk Forening 47(5): 150-158. ISSN: 0900-484X.
Descriptors: reptiles, vitamins, minerals, importance, captive.
Language of Text: Danish; Summary in Danish and English.

Fodor, K., A. Beregi, V. Molnar, F. Felkai, and S. Fekete (2004). A hullok takarmanyozasanak alapelvei, takarmanyozasi eredetu betegsegek. 2. Takarmanyozasi eredetu betegsegek. [Basic knowledge of reptiles' feeding and nutritional disorders. 2. Nutritional disorders in reptiles]. Magyar Allatorvosok Lapja 126(7): 424-432. ISSN: 0025-004X.
Descriptors: reptiles, nutritional disorders, feeding, basic knowledge of reptile nutrition, diet.
Language of Text: Hungarian; Summary in English.

Fodor, K., A. Beregi, V. Molnar, F. Felkai, and S. Fekete (2004). A hullok takarmanyozasanak alapelvei, takarmanyozasi eredetu betegsegek. 1. Altalanos takarmanyozastani ismeretek. [Basic knowledge of reptiles' feeding and nutritional disorders. 1. Basic knowledge of nutrition]. Magyar Allatorvosok Lapja 126(5): 281-289. ISSN: 0025-004X.
Descriptors: reptiles, feeding, nutritional disorders, basic knowledge, diet, nutrition.
Language of Text: Hungarian; Summary in English.

Forero Medina, G. and O. Castano Mora (2006). Kinosternon scorpioides albogulare (white-throated mud turtle). Feeding behavior and diet. Herpetological Review 37(4): 458-459. ISSN: 0018-084X.
NAL Call Number: QL640.H47
Descriptors: white-throated mud turtle, Kinosternon scorpioides albogulare, reptiles, feeding behavior, diet.

Gal, J. (2003). Meszsolerakodas vitorlas agama (Hydrosaurus amboinensis) verereiben. [Calcification in blood vessels of a sailfin lizard (Hydrosaurus amboinensis)]. Magyar Allatorvosok Lapja 125(11): 687-689. ISSN: 0025-004X.
Descriptors: reptiles, lizard, blood vessels, calcification, nutrition.
Language of Text: Hungarian; Summary in English.

Hare, K.M., S. Pledger, M.B. Thompson, J.H. Miller, and C.H. Daugherty (2006). Daily patterns of metabolic rate among New Zealand lizards (Reptilia: Lacertilia: Diplodactylidae and Scincidae). Physiological and Biochemical Zoology 79(4): 745-753. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: In addition to the effects of temperature fluctuations on metabolic rate, entrained endogenous rhythms in metabolism, which are independent of temperature fluctuations, may be important in overall energy metabolism in ectotherms. Daily entrained endogenous rhythms may serve as energy-conserving mechanisms during an animal's active or inactive phase. However, because nocturnal lizards often take advantage of thermal opportunities during the photophase (light), their daily metabolic rhythms may be less pronounced than those of diurnal species. We measured the rate of oxygen consumption (VO(2)) as an index of metabolic rate of eight temperate lizard species (four nocturnal, three diurnal, and one crepuscular/diurnal; n = 7-14) over 24 h at 13 degrees C and in constant darkness to test whether daily patterns (including amplitude, magnitude, and time of peak VO(2)) of metabolic rate in lizards differ with activity period. We also tested for phylogenetic differences in metabolic rate between skinks and geckos. Three daily patterns were evident: 24-h cycle, 12-h cycle, or no daily cycle. The skink Cyclodina aenea has a 12-h crepuscular pattern of oxygen consumption. In four other species, VO(2) increased with, or in anticipation of, the active part of the day, but three species had rhythms offset from their active phase. Although not correlated with activity period or phylogeny, amplitude of VO(2) may be correlated with whether a species is temperate or tropical. In conclusion, the metabolic rate of many species does not always correlate with the recorded activity period. The dichotomy of ecology and physiology may be clarified by more in-depth studies of species behaviors and activity periods.
Descriptors: lizards, circadian rhythm physiology, energy metabolism physiology, lizards physiology, New Zealand.

Hibma, J.C. (2004). Dietary vitamin D3 and UV-B exposure effects on green iguana growth rate: is full-spectrum lighting necessary? Bulletin of the Chicago Herpetological Society 39(8): 145-150. ISSN: 0009-3564.
Descriptors: reptiles, green iguana, dietary vitamin D3, UV-B exposure effects, full spectrum lighting, necessary, growth rate.

Hicks, J.W. and T. Wang (2004). Hypometabolism in reptiles: behavioural and physiological mechanisms that reduce aerobic demands. Respiratory Physiology and Neurobiology 141(3): 261-271. ISSN: 1569-9048.
NAL Call Number: QP121.A1 R4
Abstract: During exposure to hypoxia all vertebrates utilize a suite of cardiovascular and ventilatory responses that, in combination, strive to maintain adequate delivery of oxygen to the metabolizing tissues. In addition to maintaining oxygen delivery through cardio-respiratory responses, oxygen demands in the tissues can also be reduced. Reptiles use this alternative strategy during periods of moderate to severe hypoxia by behavioural reductions in preferred body temperature and by active down-regulation of aerobic metabolism. Below we review these two different strategies and discuss their possible mechanisms and physiological significance.
Descriptors: reptiles, hypometabolism, aerobic demands, hypoxia, cardiovascular response, ventilatory, oxygen delivery, metabolism.

Hopkins, W.A., J.H. Roe, T. Philippi, and J.D. Congdon (2004). Standard and digestive metabolism in the banded water snake, Nerodia fasciata fasciata. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 137(1): 141-149. ISSN: 1095-6433.
Abstract: Estimating energy costs by respirometry is fundamental to many studies of the ecology, behavior and evolution of reptiles. However, traditional respirometry procedures seldom incorporate objective techniques for removal of outliers from estimates of metabolic parameters. We demonstrate how computer-automated respirometry equipment, which records many respiratory measurements over short intervals, can be coupled with mathematical procedures to produce robust estimates of pre- and post-prandial metabolism in banded water snakes (Nerodia fasciata fasciata). Standard metabolic rate of N. f. fasciata was estimated to be 1.21 ml O2/h (mass = 30.21 +/- 0.74 g) at 25 degrees C. After ingestion of a fish equaling 20% of their body mass, snakes exhibited a fivefold increase in metabolic rate with peak O2 consumption rate (VO2) reaching 6.5 ml O2/h. Total cost of digestion was 5.44 kJ, equivalent to approximately 21% of the energy in the meal. Repeated measurements of metabolism in the same individuals revealed that our methods yielded similar results, even when individuals exhibited different patterns of VO2 variation between respiratory trials. Our results underscore the importance of obtaining many VO2 measurements, coupled with objective removal of outlier values from estimates of metabolic rate, especially when metabolic values are to be interpreted in a comparative context.
Descriptors: water snake, Nerodia fasciata fasciata, metabolism, digestive, standard, energy costs, computer automated, respirometry equipment, VO2 measurements.

Huang, C.H. and W.Y. Lin (2002). Estimation of optimal dietary methionine requirement for softshell turtle, Pelodiscus sinensis. Aquaculture 207(3-4): 281-287. ISSN: 0044-8486.
Abstract: A growth experiment was conducted to determine the optimal level of dietary methionine for softshell turtle, Pelodiscus sinensis. Five experimental diets analyzed to contain 0.67% to 1.24% of methionine were fed to juvenile softshell turtle with 3.2 g initial body weight for 8 weeks. The dietary protein and estimated metabolizable energy contents were 41.5% and 3.34 kcal/g, respectively. Weight gain (WG) of the turtle fed the diet containing 0.67% methionine was significantly lower than those fed diets containing 0.81% and 1.07% methionine (P<0.05). Feed conversion ratio (FCR) and protein efficiency ratio (PER) showed similar trends to that of WG. No significant difference (P>0.05) was found in body composition among turtles fed the different diets. Using a second-order polynomial regression analysis of WG and FCR on level of dietary methionine, the optimal dietary methionine content was 1.03% of diet or 2.48% of dietary protein when cystine content was 0.25% of diet or 0.60% of dietary protein.
Descriptors: reptiles, softshell turtle, Pelodiscus sinensis, optimal dietary methonine, estimation, growth experiment, diets, dietary protein.

Huang, C.H. and W.Y. Lin (2004). Effects of dietary vitamin E level on growth and tissue lipid peroxidation of soft-shelled turtle, Pelodiscus sinensis (Wiegmann). Aquaculture Research 35(10): 948-954. ISSN: 1355-557X.
NAL Call Number: SH1.F8
Abstract: A feeding trial was conducted to determine the effect of dietary vitamin E supplementation on growth, liver lipid peroxidation and liver and muscle vitamin E level of soft-shelled turtle, Pelodiscus sinensis. Eight experimental diets analysed to contain 0-457 IU vitamin E kg-1 were fed to juvenile soft-shelled turtle of 4.8 g initial body weight for 12 weeks. Weight gain (WG) of the turtles fed the diet containing no vitamin E was significantly lower than those fed diets containing 83-457 IU vitamin E kg-1 (P<0.05). Feed conversion ratio and protein efficiency ratio showed similar trends to that of WG. No significant difference (P>0.05) was found in whole-body composition among turtles fed the different diets. Dietary vitamin E requirement using WG as the response and estimated using the broken-line regression model is approximately 88 IU kg-1. Liver and muscle vitamin E content increased when dietary vitamin E level increased. Ascorbate-induced lipid peroxidation in liver tissue of turtles fed diets containing 0 and 17 IU vitamin E kg-1 was significantly (P<0.05) greater than those fed diets containing high vitamin E (> = 35 IU kg-1).
Descriptors: reptiles, soft shelled turtle, Pelodiscus sinensis, dietary vitamin E, effects, frowth, tissue lipid peroxidation, feeding trial.

Huang, C.H., W.Y. Lin, and S.M. Wu (2003). Effect of dietary calcium and phosphorus supplementation in fish meal-based diets on the growth of soft-shelled turtle Pelodiscus sinensis (Wiegmann). Aquaculture Research 34(10): 843-848. ISSN: 1355-557X.
NAL Call Number: SH1.F8
Abstract: A growth experiment was conducted to determine the effect of supplementing dietary calcium in fish meal-based diets on the growth of cultured soft-shelled turtle Pelodiscus sinensis. Juvenile soft-shelled turtles of 4.1 g mean body weight were fed nine diets containing two levels of phosphorus (2.7% or 3.0%) and analysed calcium levels ranging from 4.7% to 6.6% for 10 weeks. The growth of the turtles was enhanced when inorganic calcium was added to the diets. The weight gain of the turtles fed the control diet containing calcium solely from fish meal was the lowest among the test groups, and was significantly lower than those fed the diet containing 5.7% calcium at the 3.0% phosphorus level (P<0.05). Feed conversion and protein efficiency ratios were not affected by different dietary treatments. Whole-body moisture and crude protein contents of turtles were not affected by different dietary treatments. The body ash of turtles fed 3.0% phosphorus diets tended to be higher than turtles fed 2.7% phosphorus diets. The body calcium to phosphorus ratio of turtles fed 3.0% phosphorus diets was greater than that of turtles fed diets containing 2.7% phosphorus. Supplementation of Ca in a fish meal-based practical diet is required for the optimum growth of soft-shelled turtles.
Descriptors: reptiles, soft shelled turtle, Pelodiscus sinensis, dietary calcium, phosphorus, fish meal based diets, growth, effect, supplementary calcium, optimum growth.

Huang, C.H., W.Y. Lin, and J.H. Chu (2005). Dietary lipid level influences fatty acid profiles, tissue composition, and lipid peroxidation of soft-shelled turtle, Pelodiscus sinensis. Comparative Biochemistry and Physiology Part A Molecular and Integrative Physiology 142(3): 383-388. ISSN: 1095-6433.
Descriptors: reptiles, softshelled turtle, Pelodiscus sinensis, lipid level, fatty acid profiles, tissue composition, lipid peroxidation, diet, lipid level.

Kik, M.J. and A.C. Beynen (2003). Beoordeling van een aantal commerciele voeders voor leguanen (Iguana iguana), baardagamen (Pogona vitticeps) en land- en moerasschildpadden. [Evaluation of a number of commercial diets for iguana (Iguana iguana), bearded dragons (Pogona vitticeps), and land and marsh tortoises]. Tijdschrift Voor Diergeneeskunde 128(18): 550-554. ISSN: 0040-7453.
Abstract: Fifteen commercially available, complete diets for iguanas, bearded dragons, and chelonians were analysed and compared with the ideal composition of a diet formulated by the authors. The clinical risks of feeding with a too high or a too low content of specific nutrients are described. Nutrient deficiencies are not expected if these diets are the sole source of nutrients. However, one diet had only a marginally adequate protein content, five diets for herbivorous reptiles contained a too low percentage of crude fibre, three diets contained an undesirably high percentage of calcium, and three diets had an extremely high iron content. As a rule, the calcium and iron contents of diets are not declared on the food label, which complicates evaluation of the diets.
Descriptors: reptiles, iguana, bearded dragons, commercial diets, evaluation, land and marsh tortoises, nutrients, feeding, nutrient deficiencies, crude fibre, calcium.
Language of Text: Dutch.

Kik, M.J.L., G.M. Dorrestein, and A.C. Beynen (2003). Evaluation of 15 commercial diets and their possible relation to metabolic diseases in different species of reptiles. In: Erkrankungen der Zootiere: Verhandlungsbericht des 41 Internationalen Symposiums uber die Erkrankungen der Zoo und Wildtiere. [Proceedings of the Institute for Zoo and Wildlife Research, Berlin, No.5],May 28, 2003-June 1, 2003, Rome, Italy, p. 87-90,
Descriptors: reptiles, commercial diets, metabolic diseases, possible relation between nutrition and disease.

Klarsfeld, J.D. and M.A. Mitchell (2005). An evaluation of the gray cricket, Acheta domestica, as a source of oxyurids for reptiles. Journal of Herpetological Medicine and Surgery 15(1): 18-20. ISSN: 1529-9651.
NAL Call Number: SF997.5.R4 B85
Descriptors: reptiles, Acheta domestica, gray cricket, diet, source of oxyurids, evaluation.

Koelle, P. and E. Kienzle (2006). Diets for tube feeding or force feeding in reptile medicine. Proceedings of the Annual Conference of the Association of Reptilian and Amphibian Veterinarians 13: 23-25. ISSN: 1529-9651.
NAL Call Number: SF996.A77
Descriptors: reptiles, diet, captivity, tube feeding, force feeding, sick individuals, reptile medicine.

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.

Lei, S.J. (2006). Effects of ration level and feeding frequency on digestibility in juvenile soft-shelled turtle, Pelodiscus sinensis. Journal of Zhejiang University. Science. B 7(7): 580-585. ISSN: print: 1673-1581; online: 1862-1783.
Abstract: The effects of ration level and feeding frequency on digestibility in juvenile soft-shelled turtle, Pelodiscus sinensis, were investigated. Four ration levels 1.5%, 2.5%, 4.0% and satiation (6.0% BW/d) were used. Apparent digestibility (AD) of dry matter (DMAD), protein (PAD) and protein real digestibility (PRD) were significantly affected by ration level, but not by feeding frequency when the ration level was similar. However, the feeding frequency affected the AD, DMAD, PAD and PRD significantly when the turtles were fed to satiation. The relationship between fecal protein content (Y) and protein intake (X) can be expressed as a quadric equation: Y=-0.1742+0.1476X-0.0003X(2) (r(2)=0.876, n=27, F=93.92, P<0.01).
Descriptors: juvenile soft-shelled turtle, Pelodiscus sinensis, turtle feed analysis, feed classification, digestion physiology, feeding behavior physiology, food deprivation physiology, turtles physiology, food analysis, periodicity.

Lei, S.j. and S.z. Ye (2004). Effect of ration level on growth in juvenile soft-shelled turtles, Trionyx sinensis. Zoological Research 25(1): 43-47. ISSN: 0254-5853.
Online: http://www.bioline.org.br/abstract?id=zr04008&lang=en
NAL Call Number: QL1.T85
Descriptors: reptiles, soft shelled turtles, Trionyx sinensis, ration level, growth, effect, juvenile, diet, food intake.
Language of Text: Chinese; Summary in Chinese and English.

Li, M., B.G. Fry, and R.M. Kini (2005). Eggs-only diet: its implications for the toxin profile changes and ecology of the marbled sea snake (Aipysurus eydouxii). Journal of Molecular Evolution 60(1): 81-89. ISSN: print: 0022-2844; online: 1432-1432.
NAL Call Number: QH359.J6
Abstract: Studies so far have correlated the variation in the composition of snake venoms with the target prey population and snake's diet. Here we present the first example of an alternative evolutionary link between venom composition and dietary adaptation of snakes. We describe a dinucleotide deletion in the only three finger toxin gene expressed in the sea snake Aipysurus eydouxii (Marbled Sea Snake) venom and how it may have been the result of a significant change in dietary habits. The deletion leads to a frame shift and truncation with an accompanying loss of neurotoxicity. Due to the remarkable streamlining of sea snake venoms, a mutation of a single toxin can have dramatic effects on the whole venom, in this case likely explaining the 50- to 100-fold decrease in venom toxicity in comparison to that of other species in the same genus. This is a secondary result of the adaptation of A. eydouxii to a new dietary habit--feeding exclusively on fish eggs and, thus, the snake no longer using its venom for prey capture. This was parallel to greatly atrophied venom glands and loss of effective fangs. It is interesting to note that a potent venom was not maintained for use in defense, thus reinforcing that the primary use of snake venom is for prey capture.
Descriptors: marbled sea snake, Aipysurus eydouxii, diet, eggs only diet, toxin profile changes, venom, prey capture, dietary adaptation, loss of neurotoxicity.

Litzgus, J.D. and W.A. Hopkins (2003). Effect of temperature on metabolic rate of the mud turtle (Kinosternon subrubrum). Journal of Thermal Biology 28(8): 595-600. ISSN: 0306-4565.
NAL Call Number: QP82.2.T4J6
Descriptors: reptiles, mud turtle, Kinosternon subrubrum, temperature, metabolic rate, effect, oxygen consumption, ectotherms.

Luiselli, L. (2006). Broad geographic, taxonomic and ecological patterns of interpopulation variation in the dietary habits of snakes. Web Ecology 6: 2-16. ISSN: 1399-1183.
Descriptors: reptiles, snakes, diets, variation, habits, taxonomic, ecological, patterns, diet composition, carnivorous.

Luiselli, L., G.C. Akani, F.M. Angelici, E. Politano, L. Ude, and S.M. Wariboko (2003). Diet of the semi-aquatic snake, Afronatrix anoscopus (colubridae) in southern Nigeria. African Journal of Herpetology 52(2): 123-126. ISSN: 0441-6651.
Descriptors: reptiles, snake, Afronatrix anoscopus, diet, semi-aquatic, stomach contents, Nigeria.

Maxwell, L.K., E.R. Jacobson, and B.K. McNab (2003). Intraspecific allometry of standard metabolic rate in green iguanas, Iguana iguana. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 136(2): 301-310. ISSN: 1095-6433.
Abstract: To study the allometric relationship between standard metabolic rate and body mass (mass range 16-3627 g) in green iguanas, Iguana iguana (n=32), we measured rates of oxygen consumption (V(O(2))) at 30 degrees C during scotophase. The relationship could be described as: V(O(2))(ml h(-1))=0.478W(0.734). The resulting mass exponent was similar to the 3/4 power commonly used in interspecific curves (P>0.05), but differed from a proposed intraspecific value of 2/3 (P<0.05). The mass exponents of male (n=8) and female (n=11) iguanas did not differ (P>0.05). The mass adjusted V(O(2)) was higher than predicted from generalized squamate curves. The mean mass exponent of intra-individual allometric equations of iguanas (n=7) at varying masses during ontogeny did not differ from that of the pooled equation, indicating that scaling of V(O(2)) is similar for both between and within individuals. Thermal acclimation, compensatory changes in V(O(2)) with prolonged exposure to a constant temperature, was not observed in juvenile iguanas (n=11) between 1 and 5 weeks of acclimation at 30 degrees C.
Descriptors: reptiles, green iguanas, Iguana iguana, metabolic rate, body mass, allometric relationship, oxygen consumption.

McConnachie, S. and G.J. Alexander (2004). The effect of temperature on digestive and assimilation efficiency, gut passage time and appetite in an ambush foraging lizard, Cordylus melanotus melanotus. Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology 174(2): 99-105. ISSN: print: 0174-1578; online: 1432-136X.
NAL Call Number: QP33.J681
Abstract: In ectotherms, an increase in body temperature increases metabolic rate and may increase rates of digestive processes. We measured the thermal dependence of the apparent digestive and apparent assimilation efficiencies (ADE and AAE), gut passage time (GP) and appetite in Cordylus melanotus melanotus, a medium sized Crag Lizard, which is endemic to South Africa. Trials were conducted at 20, 22, 25, 30, 32 and 35 degrees C under controlled conditions. Trials lasted 14 days, during which, lizards were fed ca. 1 g mealworms per day. Glass beads were used as markers to determine GP at the beginning and end of trials. Faeces and urates were collected daily and oven dried at 50 degrees C. The energy content of egested matter was then measured using bomb calorimetry. ADE and AAE were not affected by temperature for either males or females. The mean+/-SE ADE and AAE were 94.4+/-0.3% and 87.2+/-0.6%, respectively. GP was not significantly different between males and females at any temperature, but decreased significantly with increasing temperature. Appetite was significantly different between the different temperatures measured. The decrease of gut passage time with increasing temperature was expected, since the digestive and assimilation efficiencies are similar over the range of temperatures tested. Lizards are thus assimilating a similar proportion of ingested energy, but at faster rates at higher temperatures. The results indicate that the digestive physiology of this species results in maximum energy gain per meal in environments where food is scarce.
Descriptors: reptiles, Crag lizard, Cordylus melanotus melanotus, digestive efficiency, assimilation efficiency, gut passage time, appetite, effect of temperature.

McWilliams, D.A. (2005). Nutrition research on calcium homeostasis. II. Freshwater turtles (with recommendations). International Zoo Yearbook 39: 77-85. ISSN: 0074-9664.
Descriptors: reptiles, freshwater turtles, nutrition research, calcium homeostasis, recommendations.

McWilliams, D. (2005). Nutrition research on calcium homeostasis. I. Lizards (with recommendations). International Zoo Yearbook 39: 69-77. ISSN: 0074-9664.
Descriptors: reptiles, lizards, diet in captivity, calcium homeostasis, nutrition research, recommendations.

Meyers, J.J. and A. Herrel (2005). Prey capture kinematics of ant-eating lizards. Journal of Experimental Biology. 208(Pt 1): 113-127. ISSN: 0022-0949.
Online: http://dx.doi.org/10.1242/jeb.01345
NAL Call Number: 442.8 B77
Abstract: While morphological and behavioral feeding specializations are obvious in many vertebrate groups, among lizards there appear to be few dietary specialists. By comparing the prey capture kinematics and overall feeding behavior in two highly specialized ant-eating lizards (Moloch horridus and Phrynosoma platyrhinos) with those of two closely related dietary generalists (Pogona vitticeps and Uma notata), we investigate whether dietary specialization has been accompanied by changes in the function and use of the feeding system. We quantified kinematic variables from high-speed video recordings (200-250 frames s(-1)) of each species feeding on ants. Prey capture was strikingly different in M. horridus to that of other species, being characterized by a suite of unusual behaviors including the lack of a body lunge, faster tongue protrusion, reduced prey processing and, most notably, the ability to modulate the slow open phase of the gape cycle. In concert, these traits make a single feeding event in M. horridus faster than that in any other iguanian lizard studied to date. Prey capture behavior in P. platyrhinos is kinematically more similar to U. notata and P. vitticeps than to M. horridus, but the ant specialists are similar in that both lack distinct prey processing behaviors, resulting in faster overall capture and feeding events. While ant feeding in P. vitticeps is faster than feeding on other prey, the duration of a single feeding event is still four times longer than in either ant specialist, because of extensive prey processing. Additionally, a phylogenetic comparison of ant specialist lizards with dietary generalists revealed that ant-eating lizards require significantly less time to capture and process prey. Thus there are not only significant behavioral modifications in these ant-eating lizards, but also multiple strategies among specialists, suggesting differing selective pressures or phylogenetic constraints in the evolution of ant eating in lizards.
Descriptors: lizards, Moloch horridus, Phrynosoma platyrhinos, feeding behavior, prey capture, kinematics, ant eating, physiology, dietary specialization, tongue protrusion, feeding speed, video recordings.

Monterrosa Salinas, M.C., M.F. Salazar Castano, and A.J. Romero (2004). Comparacion de tres dietas para el levante de neonatos de Caretta caretta (Linnaeus, 1758). [Comparison of three diets for raising of loggerhead turtle Caretta caretta hatchlings (Linnaeus, 1758).]. In: III Congreso Iberoamericano Virtual de Acuicultura (CIVA2004). Ponencias. [III Virtual Iberoamerican Aquaculture Congress (CIVA2004). Proceedings.],p. 566-595.
Online: http://www.revistaaquatic.com/civa2004
Descriptors: reptiles, loggerhead turtle, Caretta caretta, hatchlings, diet in captivity, comparison of three diets for raising loggerhead turtle hatchlings.
Language of Text: Spanish; Summary in English and Spanish.

Mushinsky, H.R., T.A. Stilson, and E.D. McCoy (2003). Diet and dietary preference of the juvenile gopher tortoise (Gopherus polyphemus). Herpetologica 59(4): 475-483. ISSN: 0018-0831.
NAL Call Number: QL640.H4
Descriptors: reptiles, gopher tortoise, Gopherus polyphemus, diet, dietary preference, juvenile.

Newbold, T.A.S. and J.A. Macmahon (2003). Prey specificity and diet selection in a variable environment: desert horned lizards (Phrynosoma platyrhinos) and ants. Ecological Society of America Annual Meeting Abstracts 88: 250-251. ISSN: 0012-9623.
Descriptors: reptiles, desert horned lizards, Phrynosoma platyrhinos, prey specificity, diet selection, variable environment, ants, meeting abstracts.
Notes: Meeting Information: 88th Annual Meeting of the Ecological Society of America held jointly with the International Society for Ecological Modeling - North American Chapter, Savannah, Georgia, USA; August 03-08, 2003.

O'Grady, S.P., M. Morando, L. Avila, and M.D. Dearing (2005). Correlating diet and digestive tract specialization: examples from the lizard family Liolaemidae. Zoology [Jena] 108(3): 201-210. ISSN: 0944-2006.
NAL Call Number: QL1.Z769
Abstract: A range of digestive tract specializations were compared among dietary categories in the family Liolaemidae to test the hypothesis that herbivores require greater gut complexity to process plant matter. Additionally, the hypothesis that herbivory favors the evolution of larger body size was tested. Lastly, the association between diet and hindgut nematodes was explored. Herbivorous liolaemids were larger relative to omnivorous and insectivorous congeners and consequently had larger guts. In addition, small intestine length of herbivorous liolaemids was disproportionately longer than that of congeners. Significant interaction effects between diet and body size among organ dimensions indicate that increases in organ size occur to a greater extent in herbivores than other diet categories. For species with plant matter in their guts, there was a significant positive correlation between the percentage of plant matter consumed and small intestine length. Herbivorous liolaemids examined in this study lacked the gross morphological specializations (cecum and colonic valves) found in herbivores in the families Iguanidae and Agamidae. A significantly greater percentage of herbivorous species had nematodes in their gut. Of the species with nematodes, over 95% of herbivores had nematodes only in the hindgut. Prevalence of nematodes in the hindgut of herbivores was 2 x that of omnivores and 4 x that of insectivores.
Descriptors: lizards, diet, feeding behavior, gastrointestinal tract anatomy, nematoda, body size, body weights, gastrointestinal contents, gastrointestinal tract parasitology, Argentina.

Overgaard, J. and T. Wang (2002). Increased blood oxygen affinity during digestion in the snake Python molurus. Journal of Experimental Biology 205(Pt 21): 3327-3334. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Many snakes exhibit large increases in metabolic rate during digestion that place extensive demands on efficient oxygen transport. In the present study, we describe blood oxygen affinity following three weeks of fasting and 48 h after feeding in the Burmese python (Python molurus). We also report simultaneous measurements of arterial blood gases and haematological parameters. Arterial blood was obtained from chronically implanted catheters, and blood oxygen-dissociation curves were constructed from oxygen content measurements at known oxygen partial pressure (P(O(2))) values at 2% and 5% CO(2). Arterial pH remained constant at approximately 7.6 after feeding, but digestion was associated with an approximately 6 mmol l(-1) increase in [HCO(3)(-)], while CO(2) partial pressure (P(CO(2))) increased from 2.21+/-0.13 kPa in fasted animals to 2.89+/-0.17 kPa at 48 h after feeding. Blood oxygen affinity in vivo was predicted on the basis of pH in vivo and the blood oxygen-dissociation curves obtained in vitro. The blood oxygen affinity in vivo increased during digestion, with P(50) values decreasing from 4.58+/-0.11 kPa to 3.53+/-0.24 kPa. This increase was associated with a significant decrease in the red blood cell [NTP]/[Hb(4)] ratio (relationship between the concentrations of organic phosphates and total haemoglobin) and a significant decrease in mean cellular haemoglobin content, which is indicative of swelling of the red blood cells. Our data for blood oxygen affinity and arterial oxygen levels, together with previously published values of oxygen uptake and blood flows, allow for a quantitative evaluation of oxygen transport during digestion. This analysis shows that a large part of the increased metabolism during digestion is supported by an increased venous extraction, while arterial P(O(2)) (Pa(O(2))) and haemoglobin saturation do not vary with digestive status. Thus, we predict that venous P(O(2)) (Pv(O(2))) is reduced from a fasting value of 5.2 kPa to 1.6 kPa during digestion.
Descriptors: reptiles, snakes, Python molurus, digestion, increased blood oxygen, metabolic rate, increase, arterial blood gases, hematological parameters.

Pafilis, P., J. Foufopoulos, N. Poulakakis, P. Lymberakis, and E. Valakos (2007). Digestive performance in five Mediterranean lizard species: effects of temperature and insularity. Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology 177(1): 49-60. ISSN: print: 0174-1578; online: 1432-136X.
NAL Call Number: QP33.J681
Abstract: Temperature sensitivity of digestive processes has important ramifications for digestive performance in ectothermic vertebrates. We conducted a comparative analysis of temperature effects on digestive processes [gut passage times (GPTs) and apparent digestive efficiencies (ADEs)] in five lacertid lizards occurring in insular (Podarcis erhardii, P. gaigeae), and mainland (P. muralis, P. peloponnesiaca, Lacerta graeca) Mediterranean environments. GPTs were negatively correlated to temperature with mainland taxa having 10-20% longer GPTs than island taxa. In contrast to previous studies that estimate ADEs using bomb calorimetry, we compare ADEs by analyzing discrete efficiencies for lipids, sugars and proteins at three temperature regimes (20, 25, and 30 degrees C); each of these categories produces different results. ADEs for lipids and sugars showed a monotonic increase with temperature whereas ADEs for proteins decreased with temperature. Island taxa had consistently higher ADEs than their mainland counterparts for lipids and for proteins but not for sugars. They are characterized by superior energy acquisition abilities despite significantly shorter GPTs. Their increased digestive performance relative to the mainland species appears to allow them to maximize energy acquisition in unproductive island environments where food availability is spatially and seasonally clustered.
Descriptors: reptiles, Mediterranean lacertid lizards, digestive performance, effects of temperature, insularity, gut passage time, apparent digestive efficiencies.

Pan, Z.C., X. Ji, H.L. Lu, and X.M. Ma (2005). Metabolic response to feeding in the Chinese striped-necked turtle, Ocadia sinensis. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 141(4): 470-475. ISSN: 1095-6433.
Abstract: We measured oxygen consumption in juvenile Chinese striped-necked turtles (Ocadia sinensis) after they ingested food, either as a single meal or as double meals, to examine the influence of meal type and feeding frequency on specific dynamic action (SDA). Temporal variation in oxygen consumption after feeding was evident in the ingesting turtles but not in the unfed control turtles. In the single-meal experiment, the peak metabolic rate and the integrated SDA response (the whole energetic cost for the processes of digestion) both did not differ between turtles ingesting mealworms and shrimps when the influence of variation in ingested energy was removed, and the time to reach peak metabolic rate was not affected by meal type and the amount of food ingested. Turtles in the double-meal experiment ingested more energy and hence had a prolonged duration of SDA response than did those in the single-meal experiment, but the integrated SDA response did not differ between both experimental treatments when the influence of variation in ingested energy was removed. Our results show that meal type and feeding frequency have important consequences on the SDA response of juvenile O. sinensis. As the integrated SDA response remained remarkably constant either between turtles ingesting different food or between turtles ingesting the same food but at different frequencies when the influence of variation in ingested energy was removed, we therefore conclude that the energetic cost associated with ingestion is primarily determined by energy content of food ingested in juvenile O. sinensis.
Descriptors: young turtles, Ocadia sinensis, anatomy, histology, nutrition, physiology, body weight, digestion, energy intake, energy metabolism, feeding behavior, lipids chemistry, oxygen consumption, time factors, feeding, metabolic response, energy content, metabolic rate.

Paolucci, M., S. Buono, R. Sciarrillo, and R. Putti (2006). Effects of leptin administration on the endocrine pancreas and liver in the lizard Podarcis sicula. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 305(5): 383-395. ISSN: print: 1548-8969; online: 1552-499X.
NAL Call Number: QL1.J854
Abstract: In this study, we investigated the presence of leptin receptor in pancreatic islets and the effect of exogenous leptin administration in Podarcis sicula on glucose metabolism. Our data show the presence of leptin receptor immunoreactivity in the endocrine pancreas suggesting that leptin may act at a peripheral level as previously postulated in mammals. The effects of short- and long-term and dose-response treatment with supraphysiological concentrations of leptin on circulating levels of insulin, glucagon and glucose in the blood have been evaluated. Taken together, our results indicate that leptin treatment was followed by an increase in insulin, glucagon and glucose in the blood, depending on the dose of leptin. Moreover, leptin treatment brought about a decrease of glycogen and the appearance of tyrosine-phosphorylated proteins in the liver. This study shows that in the lizard P. sicula leptin is involved in glucose metabolism.
Descriptors: lizard, Podarcis sicula, islets of Langerhans drug effects, leptin pharmacology, liver drug effects, lizards physiology, blood glucose, dose response relationship, drug, electrophoresis, polyacrylamide gel, glucagon blood, immunohistochemistry, insulin blood, islets of langerhans metabolism, liver metabolism, liver extracts analysis, mice, receptors, cell surface metabolism.

Qian GuoYing and Zhu QiuHua (2003). Effects of living space on nutrient components of Chinese soft-shelled turtle (Trionyx sinensis). Acta Hydrobiologica Sinica 27(2): 217-220. ISSN: 1000-3207.
NAL Call Number: QH540
Descriptors: reptiles, Chinese soft shelled turtle, Trionyx sinensis, living space, effects, nutrient componenets, husbandry, farmed animals.
Language of Text: Chinese.

Rocha, C.F., D. Vrcibradic, and M. Van Sluys (2004). Diet of the lizard Mabuya agilis (Sauria; Scincidae) in an insular habitat (Ilha Grande, RJ, Brazil). Revista Brasleira De Biologia. [Brazilian Journal of Biology]. 64(1): 135-139. ISSN: 1519-6984.
Abstract: We examined the stomach contents of 21 specimens of Mabuya agilis (Sauria; Scincidae) collected during February 2001 at the restinga habitat of Praia do Sul, in Ilha Grande, RJ, Brazil. Diet was composed of various types of small arthropods, with no plant material being eaten. Spiders were the most important items in the diet, followed by orthopterans. Apart from the absence of isopterans, the diet of Mabuya agilis from this insular area was similar to those of other conspecific mainland populations. This suggests that factors such as insularity and the absence of other small sympatric lizards may not have a significant effect on the feeding habits of the Praia do Sul population.
Descriptors: reptiles, diet, lizard, Mabuya agilis, food habits, physiology, gastrointestinal contents, Brazil.

Rogner, M. (2005). Wasserschildkroeten Ueber ihre Unterbringung und Ernaehrung. [Turtles. Information on their care and feeding.]. Aquarium Bornheim 431: 66-71. ISSN: 0341-2709.
Descriptors: reptiles, turtles, information, care, feeding, diet, housing.
Language of Text: German.

Saad, C.R., A.R. Alimon, H.H. Tong, and P. Roustaian (2003). Practical diet evaluation with hatchlings of soft-shell turtle, Trionyx sinensis Wiegmann, in the tropics. Journal of Applied Ichthyology 19(1): 62-63. ISSN: 0175-8659.
NAL Call Number: QL614.Z44
Descriptors: reptiles, soft shell turtle, Trionyx sinensis, hatchlings, practical diet evaluation, tropics.

Secor, S.M. (2005). Evolutionary and cellular mechanisms regulating intestinal performance of amphibians and reptiles. Integrative and Comparative Biology 45(2): 282-294. ISSN: print: 1540-7063; online: 1557-7023.
NAL Call Number: QL1.I67
Descriptors: reptiles, evolutionary, cellular, mechanisms, intestinal performance, regulating, amphibians.

Seney, E.E. and J.A. Musick (2005). Diet analysis of Kemp's ridley sea turtles (Lepidochelys kempii) in Virginia. Chelonian Conservation and Biology 4(4): 864-871. ISSN: 1071-8443.
Descriptors: reptiles, Kemp's ridley sea turtles, Lepidochelys kempii, diet analysis, diet, Virginia.

Stone, M.D. and D. Moll (2006). Diet-dependent differences in digestive efficiency in two sympatric species of box turtles, Terrapene carolina and Terrapene ornata. Journal of Herpetology 40(3): 364-371. ISSN: 0022-1511.
NAL Call Number: QL640.J6
Descriptors: reptiles, box turtles, Terrapene carolina, Terrapene ornata, digestive efficiency, diet dependent differences, digestive physiology.

Struck, U., A.V. Altenbach, M. Gaulke, and F. Glaw (2002). Tracing the diet of the monitor lizard Varanus mabitang by stable isotope analyses (delta(15)N, delta(13)C). Die Naturwissenschaften 89(10): 470-473. ISSN: print: 0028-1042; online: 1432-1904.
Abstract: In this study, we used analyses of stable isotopes of nitrogen (delta(15)N) and carbon (delta(13)C) to determine the trophic ecology of the monitor lizard Varanus mabitang. Stable isotopes from claws, gut contents, and soft tissues were measured from the type specimen. Samples from Varanus olivaceus, Varanus prasinus, Varanus salvator, the herbivorous agamid lizard Hydrosaurus pustulatus, and some plant matter were included for comparison. Our data show a rapid decrease in delta(13)C (about 10 per thousand) from food plants towards gut contents and soft tissues of herbivorous species. For the varanids, we found a significant linear correlation of decreasing delta(13)C and increasing delta(15)N from herbivorous towards carnivorous species. In terms of trophic isotope ecology, the type specimen of V. mabitang is a strict herbivore. Thus it differs significantly in its isotopic composition from the morphologically next closest related species V. olivaceus. The most highly carnivorous species is V. salvator, while delta(15)N values for V. prasinus and V. olivaceus are intermediate. Claws provide very valuable samples for such measurements, because they can be sampled from living animals without harm. Additionally, their range of variability is relatively small in comparison with measurements from soft tissues.
Descriptors: reptiles, monitor lizard, Varanus mabitang, physiology, diet, animal feed, carbon isotopes, isotope labeling methods, nitrogen isotopes, Germany.

Su, Y., S.C. Fong, and M.C. Tu (2005). Food habits of the sea snake, Laticauda semifasciata. Zoological Studies 44(3): 403-408. ISSN: 1021-5506.
NAL Call Number: QL307.2.C54
Descriptors: reptiles, sea snake, Laticauda semifasciata, diet, food habits, feeding habits.

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.

Toledo, L.F., A.S. Abe, and D.V. Andrade (2003). Temperature and meal size effects on the postprandial metabolism and energetics in a boid snake. Physiological and Biochemical Zoology 76(2): 240-246. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: We investigated the combined effect of meal size and temperature on the aerobic metabolism and energetics of digestion in Boa constrictor amarali. Oxygen uptake rates (Vd2;o2) and the duration of the digestion were determined in snakes fed with meals equaling to 5%, 10%, 20%, and 40% of the snake's body mass at 25 degrees and 30 degrees C. The maximum Vd2;o2 values attained during digestion were greater at 30 degrees C than at 25 degrees C. Both maximal Vd2;o2 values and the duration of the specific dynamic action (SDA) were attained sooner at 30 degrees C than at 25 degrees C. Therefore, the temperature effect on digestion in Boa is characterized by the shortening of the SDA duration at the expense of increased Vd2;o2. Energy allocated to SDA was not affected by meal size but was greater at 25 degrees C compared to 30 degrees C. This indicates that a postprandial thermophilic response can be advantageous not only by decreasing the duration of digestion but also by improving digestive efficiency. Maximal Vd2;o2 and SDA duration increased with meal size at both temperatures.
Descriptors: reptiles, boid snake, Boa constrictor amarali, temperature, meal size, effects, postprandial metabolism, energetics.

Vincent, S.E., B.R. Moon, R. Shine, and A. Herrel (2006). The functional meaning of "prey size" in water snakes (Nerodia fasciata, Colubridae). Oecologia 147(2): 204-211. ISSN: 0029-8549.
NAL Call Number: QL750.O3
Abstract: The evolutionary success of macrostomatan (enlarged-gape) snakes has been attributed to their ability to consume large prey, in turn made possible by their highly kinetic skulls. However, prey can be "large" in several ways, and we have little insight into which aspects of prey size and shape affect skull function during feeding. We used X-ray videos of broad-banded water snakes (Nerodia fasciata) feeding on both frogs and fish to quantify movements of the jaw elements during prey transport, and of the anterior vertebral column during post-cranial swallowing. In a sample of additional individuals feeding on both frogs and fish, we measured the time and the number of jaw protractions needed to transport prey through the buccal cavity. Prey type (fish vs. frog) did not influence transport kinematics, but did influence transport performance. Furthermore, wider and taller prey induced greater movements of most cranial elements, but wider prey were transported with significantly less anterior vertebral bending. In the performance trials, heavier, shorter, and wider prey took significantly more time and a greater number of jaw protractions to ingest. Thus, the functional challenges involved in prey transport depend not only upon prey mass, but also prey type (fish vs. frog) and prey shape (relative height, width and length), suggesting that from the perspective of a gape-limited predator, the difficulty of prey ingestion depends upon multiple aspects of prey size.
Descriptors: water snakes, Nerodia fasciata, Colubridae anatomy and histology, Colubridae physiology, predatory behavior physiology, biomechanics, body size, head anatomy and histology, head physiology.

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.

Witberg, M. and G. Van Zyl (2006). Atractaspididae Homoroselaps lacteus (Linnaeus, 1754) spotted harlequin snake diet/predation. African Herp News 40: 21-23. ISSN: 1017-6187.
Descriptors: reptiles, spotted harlequin snake, diet, Atractaspididae Homoroselaps lacteus, predation.

Yang GongMing, Xu HuaiDe, Duan XuChang, and Li ZhiCheng (2003). Study on the nutritional components of soft-shelled turtle. Acta Nutrimenta Sinica 25(4): 443-445. ISSN: 0512-7955.
Descriptors: reptiles, soft shelled turtle, nutritionsl components, study, diet, food.
Language of Text: Chinese.

Zhang, F.Y. and H.X. Gu (2005). Artificial feeding of baby turtle of Chelonia mydas. Sichuan Journal of Zoology 24(3): 412-413. ISSN: 1000-7083.
Descriptors: reptiles, baby turtle, Chelonia mydas, diet, captivity, artificial feeding.
Language of Text: Chinese; Summary in Chinese and English.

Zhou, X., M. Xie, C. Niu, and R. Sun (2003). The effects of dietary vitamin C on growth, liver vitamin C and serum cortisol in stressed and unstressed juvenile soft-shelled turtles (Pelodiscus sinensis). Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 135(2): 263-270. ISSN: 1095-6433.
Abstract: We studied the effect of dietary vitamin C on growth, liver vitamin C and serum cortisol levels in stressed and unstressed juvenile soft-shelled turtles. Turtles were fed with vitamin C supplementation at dosages of 0, 250, 500, 2500, 5,000 or 10,000 mg/kg diet for 4 weeks. Vitamin C supplementation exerted significant effects on specific growth rate and liver vitamin C concentrations. The specific growth rate peaked in the group fed at 500 mg/kg diet, while liver vitamin C levels increased with increasing dietary vitamin C levels. Serum cortisol concentrations did not differ between groups of turtles fed diets supplemented with vitamin C in the range of 0-10,000 mg/kg. After acid stress, hepatic vitamin C levels were unaffected, while serum cortisol in the control group was significantly elevated (P<0.01). The other five groups of turtles did not show significant changes in serum cortisol compared with pre-stress levels.
Descriptors: reptiles, soft shelled turtles, Pelodiscus sinensis, dietary vitamin C, effects, growth, liver vitamin C, serum cortisol, stressed, unstressed, juveniles.

Zhou, X.Q., C.J. Niu, and R.Y. Sun (2005). The effect of vitamin C on stress withstanding capability in the juvenile soft-shelled turtle (Pelodiscus sinensis). Aquaculture Nutrition 11(3): 169-174. ISSN: 1353-5773.
NAL Call Number: SH156.A658
Descriptors: reptiles, turtle culture, soft-shelled turtle, Pelodiscus sinensis, juveniles, ascorbic acid, dietary supplements, erythrocytes, phagocytosis, animal stress, pH, water quality, blood serum, Vibrio parahaemolyticus, antimicrobial agents, disease control, Pelodiscus sinensis, acid stress.

Zhou XiaoQiu, Yang Feng, Zhou AnGuo, Cai JingYi, and Yan BenJu (2003). Methionine requirement of juvenile Chinese soft shell turtle. Acta Hydrobiologica Sinica 27(1): 69-73. ISSN: 1000-3207.
NAL Call Number: QH540
Abstract: 90 juvenile Chinese soft shell turtles (initial weight, 17.64+or-0.25 g) were divided into six groups and were fed with semipurified diets (cystine content, 0.56%) having different methionine contents (i.e., 0.82%, 1.12%, 1.32%, 1.52%, 1.72%, 2.02%) for 45 days. The experimental diets consisted of white fish meal, liver meal, soya protein meal, gluten, fish oil, corn oil, sucrose, alpha -starch, and premixtures of amino acids, vitamins and minerals. The liveweight, liver weight, body fat content, and body methionine content were determined at the end of the feeding trial. Significant differences in growth rate, feed conversion rate, liver weight/body weight ratio, and methionine retention rate were observed among turtle groups fed the diets with different methionine contents (P<0.01). Significant differences were also noted in the feed intake, liver weight, body fat content and protein retention rate of turtles fed different methionine levels (P<0.05). No significant difference in body protein content was observed among groups. Thus, the methionine requirement of the juvenile soft shell turtle is 1.28 (dietary base) or 3.07% (protein base), based on a diet containing 0.56% cystine. Courtesty of CAB Abstracts.
Descriptors: reptiles, Chineses soft shell turtle, Pelodiscus sinensis, methionine requirement, juvenile, diets.
Language of Text: Chinese; Summary in English.