By: Hanping Wang, PhD, Senior Scientist
Yellow Perch Breeding: A large numbers of neo-male broodstock of yellow perch with a female genotype have been created, using the superior neomale broodstock, fast-growing all-female yellow perch populations have been produced. The large numbers of superior neomale broodstock from this project enable us to produce commercial-scale of all-female monosex yellow perch. Growth performance test of the all-females vs. mixed-sex group in tank system was conducted in Piketon Research Station. By the end of the experiment, all-females grew 26.3% faster than mixed group, and 66.0% faster than males. Larger scale growth performance test of the all-females vs. mixed-sex group will be conducted in 2017.
Bluegill Breeding: A large numbers of neo-female broodstock of bluegill with a male genotype have been created. All-Male or near-all-male bluegill populations have been successfully produced. Results from testing all-male or near-all-male bluegill populations at two locations showed: 1) Weight gain and growth rate of all-male stock were 2.1 times as that of regular stocks; 2) All-male groups had significantly uniformed size and lower coefficient of variation; and 3) Survival of all-male groups was significant higher than that of mixed sex groups due to more uniformed size. A successful creation of genetically male bluegill strains would have a tremendous impact on the sunfish aquaculture industry by increasing growth rate of 30- 35% and saving energy expenditure of 20-30% for sex growth.
Identify the best genetically distinct largemouth bass populations for industry: In 2016-2017, we genotyped 280 additional largemouth bass from 28 wild populations across the United States using eight microsatellite loci. We are conducting experiment to compare growth performance of the identified group vs. Ohio control group in indoor system. The fish were stocked and are being cultured communally in two replicate tanks. As of November, fish from the identified group grew 126.6% faster than control group. An experiment on evaluation of soybean meal as protein source for northern and southern largemouth bass was completed. The results indicated that northern subspecies had superior growth compared to Florida subspecies in current experimental setup. The results provide a valuable base for developing fast-growing largemouth bass broodstocks for industry.
Genetic improvement of SMD utilization rate of Largemouth bass (LMB) : A study on evaluation of growth response of Northern and Southern subspecies to SMD and fishmeal-based diet (FMD) was completed. Four diets were formulated with varying levels of dietary soybean meal 0 (control), 12, 25, and 40%, respectively. The feeding trial with 4 replicates lasted for 12 weeks. Results showed that 1) Northern subspecies grew significantly faster and gained significantly higher body weight than Southern subspecies across the four levels of soybean meal diets; 2) Northern subspecies utilized SMD significantly better than Southern subspecies; 3) Based on the feed efficiency, 12% dietary soybean meal inclusion is optimal for Southern largemouth bass. 25% soybean meal can be used in diet for Northern largemouth bass; 4) The growth of largemouth bass decreased with increasing dietary soybean meal level and no significant differences were observed among the treatments for two subspecies. Diet with 40% soybean meal inclusion is acceptable for juveniles.
Genomic sequence and tool development: We have completed whole genome sequencing of yellow perch and bluegill. It is the first Percidae and Centrarchidae (sunfish) that have been fully sequenced. Yellow perch belong to the family Percidae including about 200 species in 10 genera. The perch, darter, and their relatives are in this family and well-known species of great economic value include the three species of perch, walleye, sauger and ruffe. Information of the whole genome in these two species makes it possible to see how genes interact with each other, and examine the exact gene that governs economically important traits such as fast-growing and disease resistance. The perch and sunfish genome sequence data provide useful genetic resource and lay important foundation for discovering molecular mechanism of growth, sex determination and sex control, reproduction related to aquaculture and conservation of wild stocks for over 100 economically and environmentally important percid and sunfish species. We also completed whole genome sequencing of two strains of bluegill to develop SNPs and investigate genomic base of sex determination for developing mono-sex population, and results have been published by a high impact journals SCIENTIFIC REPORT and PLOS ONE.
Promotion of international training and collaborations: Research in aquaculture genetics and breeding at OSU South Centers has produced international impacts and attracted about thirty scientists and international scholars to work in the Aquaculture Research Center and Genetics Lab at Piketon. In 2016-2017, the lab trained three visiting Ph.D. students and post-doctoral researchers, and two new ones are coming this year. They also significantly contributed to the aquaculture program’s success at the OSU South Centers. We organized the 2nd international conference on perch and bass.