APPLIED RESEARCH IN AQUACULTURE AND FISHERIES TO IMPACT FISH PRODUCTION, PREVENT INVASION OF NON-NATIVE SPECIES, AND PROMOTE RECREATIONAL FISHERIES

ObjectivesResearch on yellow perch. - To examine the sex ratio and growth rate of progenies sired by potentially sex reversed neomales and controls reared in parallel groups (OSU) and separately in a "common garden" design by factorial crossing (UW-Milwaukee, J. Sepulveda).To examine outcross performance (fertilization, survival, growth rates at 30 and 90 days, feed efficiency) will be evaluated among crosses of Ohio strain and hybrids between UW-M genetically improved yellow perch x Ohio perch sperm.To optimize high-throughput cryopreservation methods for yellow perch sperm and develop a pilot cryo-bank of sex-reversed ("XX") male yellow perch sperm, which will be immediately available for use by researchers and fish farmers in the North-Central region to produce all-female progenies for grow-out.Research on walleye. - To produce meiotic gynogenetic (XX) walleye sing UV-irradiated yellow perch sperm and to compare two methods (immersion and feeding) to sex reverse gynogenetic fish into neomales (sperm producing XX fish) using 17α-methyltestosterone (MT). Optimize the use of pressure shocks to produce triploid walleyes.Compare growth, survival, and gonad development of the following four experimental progeny groups: (a) diploid walleyes (sex genotypes: XX & XY), (b) triploid walleyes (XXX & XXY), (c) all-female diploid walleyes (XX), and (d) all-female triploid walleyes (XXX).Cost-benefit analysis will be conducted to evaluate the potential economic viability of culture of walleye with these superior production traits . These experiments will be conducted in raceway tanks (OSU, UW-Madison, and Reef Systems Coral Farm Inc, New Albany, OH) and micro-ponds (Reef Systems Coral Farm Inc, New Albany, OH and Northey Farms LLC, Deerfield, WI).To refine walleye sperm cryopreservation methods and develop a pilot cryobank for walleye neomale sperm to allow for immediate availability to research laboratories and fish farms in the North Central region.Research on Rainbow trout nutrition. - To evaluate rainbow trout growth, survival, and feed conversion efficiency throughout a period of juvenile growth (50-fold weight increase), subadult (100-fold) and marketable size (450 g ~500 days) when fed the experimental diets based on fish meal (control) and defatted fish meal with supplemented specific lipids (fatty acid ethyl esters) .Evaluate fatty acid profiles in liver and muscle following the feeding trial, and calculate fatty acid deposition based on these data.To determine possible hepatotoxic effects of high-oleic soybean oil dietary level via histological analysis of fish livers and posterior intestine (enteritis) following the feeding trial (60 days and terminal samples).To prepare fermented fish waste by fermentation with industrial acid whey cultures (pH 4.5) derived from cottage, cheddar, mozzarella (Lactococcus sp.) or Greek yogurt (Lactococcus sp. and Lactobacillus sp.) operations.To prepare diets for rainbow trout, Nile tilapia and zebrafish based on previous formulation experience of the host laboratories and perform feeding experiments that would result in 10 fold body weight increase allowing us to observe any biologically significant differences between treatment groups. Zebrafish feeding trials will include 3 generations test of the effect of dietary history on growth and reproductive efficiency.To implement a systems approach that will incorporate elucidation of the physiological response and molecular mechanisms involved in transport and absorption of proteins, peptides and amino acids at the gastro- intestinal level related to diet formulations that will utilize fish waste-dairy waste fermentation ingredients.Research on Asian carps. - To determine methods for inducing polyploidy in bighead carp by characterizationof the optimum pressure, temperature, and duration for shocking bighead carp zygotes. Specifically, we will test the efficacy of three types of physical shocks (cold, heat and pressure).To examine ploidy induction rate of embryos and juveniles under different shockprotocols to obtain the highest survival of triploid or tetraploid fish.To optimize larval rearing of bighead carp by examining the best first live feed,stocking density, temperature and resulting survival and frequency of deformities of diploid and polyploid fish under different rearing conditions (stagnant and flow through systems).Research on cichlids hybridization. - Describe techniques of controlled reproduction of redhead cichlid (Vieja melanura) and in vitro hybridization of redhead cichlid females with midas males (red parrots, P). We will examine rearing conditions for larvae/juveniles using live and formulated diets and described the growth and color metamorphosis, maturation and fertlility in red parrots.Follow the growth and maturation of different morphs of backcross hybrids, Parrot x A. citrinellum (M), P x C. urophthalmus (U) and P x V. melanura (S).