2009 Annual Report
1a.Objectives (from AD-416)
Develop and refine year-round production of hybrid striped bass
fingerlings through photothermal, dietary, and culture manipulation.
Increase hybrid striped bass production efficiency through physiological
control of stress, gender, and hormonal growth factors. Increase hybrid
striped bass production efficiency by refining nutrient requirements,
manipulating feeding strategy and diet nutrient density, and reducing
fish meal and oil content. Develop genetically superior Morone species.
1b.Approach (from AD-416)
Evaluate photothermal manipulation and hormonal stimulation to induce off-season spawning of Morone sp. Evaluate the effects of stocking density, feeds and feeding strategies, and environmental conditions on survival and growth of hybrid striped bass and fingerlings in tanks/ponds. Characterize the physiological stress response to production practices with respect to environmental, nutritional, and genetic factors. Characterize gender-related production characteristics and develop methods of sex reversal to produce monosex populations. Determine conditions that increase growth-promoting actions of growth factors such as growth hormone, and insulin-like growth factors. Determine the nutrient digestibility of traditional and alternative feed ingredients to replace fish meal. Determine or refine nutrient requirements for different life stages and production systems. Use phenotypic and genotypic characters to evaluate new strains for economically revelant traits. Identify phenotypic and molecular differences among stocks of white/striped bass. Implement a selective breeding program to produce progeny with desired traits. Develop molecular markers for economically relevant traits to aid selective breeding efforts.
This project will terminate in early FY10. Patterns of succession in ponds of live food organisms consumed by first-feeding hyrbrid striped bass (Morone chrysops x Morone saxatilis; HSB) fingerlings were determined, which enables prediction of when to stock fingerlings to ensure high growth and survival. Indoor, year-round HSB fingerling production was advanced. An inexpensive, modular system was developed that produced a continuous supply of rotifers for feeding larvae. Brine shrimp microcysts were identified as a good live food substitute for rotifers in feeding larval HSB. Automated harvest of zooplankton from outdoor ponds to feed HSB fingerlings in indoor tanks was accomplished during the off-season. A relationship was described between stocking density and HSB fry growth in indoor tanks with unlimited food that optimizes commercial hatchery production.
Plasma IGF-I concentrations in HSB were highly correlated with temperature, photoperiod, feed intake, and dietary carbohydrate or tryptophan levels, and confirm that IGF-I levels can be used earlier than previously thought to identify diets and culture conditions that optimize growth.
The composition, digestibility of nutrients, and the availability of amino acids, fatty acids, and energy in a variety of plant and animal feedstuffs and oils as alternatives to marine fish meal and oil were determined for HSB. Pet-food-grade poultry by-product meal (PBM) supplemented with the two most-limiting amino acids on an ideal protein basis can substitute 50% of the fish meal in HSB diets for pond and tank production. Supplementing diets with free-amino acids did not result in more nitrogen excretion when compared to unsupplemented diets. The dietary requirements for the essential amino acids tryptophan, leucine, isoleucine, and valine were determined for HSB. Although manipulation of the dietary ratio of highly branched (amylopectin) to less-branched starch (amylose) somewhat increased carbohydrate use and decreased fat deposition, the compositional gains and losses were minimal. Carbohydrate is not a major oxidative substrate for HSB, and the limits for dietary manipulation of carbohydrate use may be extremely narrow barring selection for improved strains. Upper and lower temperature limits of HSB feeding activity were determined and resulted in temperature-specific feeding recommendations and more efficient commercial diet formulations.
We produced and performance-tested 122 unique genetic groups of white bass and 147 unique genetic groups of hybrid striped bass, which yielded 290,000 larvae and 134,000 Phase-I fingerlings, and generated over 6,700 genotypes for assigning family lineage to fingerlings. Larvae size at 5 days post-hatch depended on the female, but not the male parent. White bass egg size was independent of female size. A cortisol dose response curve, the first such response curve published on this species, to a low water stressor was created using 3-year-old adult white bass and yearling Phase II white bass fingerlings. Cortisol concentrations differed significantly between male and female white bass when stressed, with females having a significantly lower response.
Record number of Phase-I white bass fingerlings produced: In order to advance the selective breeding program for hybrid striped bass broodstock beyond its infancy, substantial numbers of offspring resulting from multiple breeding combinations need to be reared and performance-tested in appropriate production environments. Scientists at the Stuttgart National Aquaculture Research Center, Arkansas, produced and performance-tested 122 unique genetic groups of white bass and 147 unique genetic groups of hybrid striped bass. Results of this effort yielded 290,000 larvae and 134,000 Phase-I fingerlings, and generated over 6,700 genotypes for assigning family lineage to fingerlings. These results will be used to identify superior broodstock for genetic improvement and distribution to hybrid striped bass producers.
Hybrid striped bass diets formulated for extreme temperatures: Seasonal extremes in pond water temperatures alter the way fish eat and their digestive efficiency, which can lead to wasted feed, poor water quality, and increased incidence of disease. Studies conducted on hybrid striped bass by scientists at the Stuttgart National Aquaculture Research Center, Arkansas, defined the upper and lower temperature limits of feeding activity, and resulted in temperature-specific feeding recommendations and more efficient commercial diet formulations for late winter/early spring feeding. Development of season-specific diets for fish will lead to more efficient, sustainable aquaculture production in the U.S.
White bass mothers, but not fathers, influence early fingerling growth: In order to develop improved lines of hybrid striped bass broodstock, superior parents must be identified, and how each parent's contribution affects the offspring's performance at each stage of production must be quantified. Scientists at the Stuttgart National Aquaculture Research Center, in collaboration with scientists from the University of Arkansas at Pine Bluff, Arkansas, conducted a study to determine the effect of lineage on early growth of white bass fingerlings. This research showed that larvae size at 5 days post-hatch depended on the female, but not the male parent. These results will lead to a better understanding of genetic influence on larval traits of white bass and the development of a selectively improved line of hybrid striped bass broodstock for distribution to producers nationwide.
Sex linked to stress response in white bass: Hybrid striped bass farmers would benefit if the physiological stress response could be reduced by a selective breeding program. Scientists at the Stuttgart National Aquaculture Research Center conducted an intensive study to determine if sex would influence how white bass broodstock responded to a low-water stress event. This study demonstrated clearly that white bass females responded differently than white bass males to the stress event, and that females exhibited a lower stress response. This research will lead to improved broodstock that are better able to cope with production-related stress and are less susceptible to stress-related death and disease.
Pre-natal diet does not affect white bass egg size: Quantification of reproductive output parameters from multiple spawning groups is vital for evaluation and comparison of broodstock performance from different conditioning groups and across reproductive years. In evaluating the effect of diet on egg size, scientists at the Stuttgart National Aquaculture Research Center fed two formulations of a high-protein diet to female white bass during their egg development stage. Results of this research indicate that egg size was not affected by either diet and was independent of female size. This research will lead to a refinement of conditioning procedures to optimize reproductive output for the hybrid striped bass industry.
Alternative ingredients lead to more cost-effective diets for hybrid striped bass: Feed mills need accurate digestibility data for variety of feedstuffs that are used to substitute for marine fish meal in diets for all life stages of hybrid striped bass. Collaborative studies by scientists from the Stuttgart National Aquaculture Research Center, Arkansas, and Kentucky State University identified the best method to determine feedstuff digestibility in market-size hybrid striped bass and used this method to quantify essential nutrient and amino acid availability for feedstuff alternatives to marine fish meal. These data now are being used by feed mills to formulate more cost-effective, sustainable diets for hybrid striped bass and will advance efforts to develop life-cycle-specific diets for fish as is done for other livestock production.
Rawles, S.D., Gaylord, T.G., McEntire, M.E., Freeman, D.W. 2009. Evaluation of poultry by-product meal in commercial diets for hybrid striped bass (Morone chrysops X M. saxatilis) in pond production. Journal of the World Aquaculture Society. 40:141-156.
Rawles, S.D., Thompson, K.R., Metts, L.S., Gannam, A.L., Twibell, R.G., Brady, Y.J., Webster, C.D. 2009. A comparison of two fecal collection methods for protein and amino acid digestibility coefficients for menhaden fish meal and two grades of pultry-by-product meals in market-size sunshine bass (Morone chrysops X M. saxatilis). Aquaculture Nutrition. 16:81-90.
Gaylord, T.G., Barrows, F., Rawles, S.D., Liu, K., Bregitzer, P.P., Hang, A., Obert, D.E., Morris, C.F. 2009. Apparent digestibility of nutrients in extruded diets from cultivars of barley and wheat selected for nutritional quality in rainbow trout Oncorhynchus mykiss. Aquaculture Nutrition. 15:306-312.
Gaylord, T.G., Barrows, F., Rawles, S.D. 2009. Apparent Amino Acid Availability from Feedstuffs in Extruded Diets for Rainbow Trout Oncorhynchus mykiss. Aquaculture Nutrition. doi: 10.1111/j.1365-2095.2009.00678.x
Ludwig, G.M., Lochmann, S. 2009. Tank culture of sunshine bass without using rotifers. North American Journal of Aquaculture. 71:224-228.
Ludwig, G.M., Lochmann, S.E. 2009. Effect of temperature on larval sunshine bass growth and survival to the fingerling stage. North American Journal of Aquaculture. 71:260-266.
Subhadra, B., Lochmann, R., Rawles, S.D., Chen, R. 2006. Effect of fish-meal replacement with poultry by-product meal on the growth, tissue composition and hematological parameters of largemouth bass (micropterus salmoides) fed diets containing different lipids. Aquaculture. 260:221-231.
Davis Jr, K.B., McEntire, M.E. 2009. Comparison of the cortisol and glucose stress response to acute confinement among white bass, Monrone chrysops, striped bass, Monrone saxatilis and sunshine bass, Monrone chrysops x Morone saxatilis. Journal of the World Aquaculture Society. 40(4):567-572.