2007 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.
Measure genetic variation in production traits of striped bass and white bass and correlations between traits; develop genomic resources for integrating functional genomics into the striped bass and white bass applied breeding programs; and, increase biological efficiency through selective breeding of hybrid striped bass and transfer improved germplasm to the U.S. hybrid striped bass industry.
Develop year-round spawning strategies for captive broodstock and larviculture methods for sustainable seed production of important warmwater finfish species, especially hybrid striped bass.
Offset reliance on fish meal and fish oil in feeds for all life stages of hybrid striped bass, increase use of plant products (particularly biofuel co-products in warm water aquafeeds), investigate immune enhancement, disease and stress resistance in hybrid striped bass by probiotics, nutraceuticals, and feed additives, and develop feeds and feeding practices for optimal water quality in pond and tank-reared fish.
Correlate growth, feed efficiency, carbohydrate use, disease and stress resistance to key hormones, regulatory genes, and proteins in striped bass and white bass that can be used to genetically select and improve strains of broodstock used in the U.S. hybrid striped bass industry.
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.
REPLACEMENT OF FISH MEAL WITH POULTRY BY-PRODUCT IN DIETS FOR POND-RAISED HYBRID STRIPED BASS:
The reduction of fishmeal in aquafeeds is a high priority need of the aquaculture industry due the high cost of fish meal and its high demand by other livestock producers. Scientists at the HKD Stuttgart National Aquaculture Research Center replaced nearly half the fishmeal in commercial hybrid striped bass diets with a lower cost poultry by-product and two added amino acids without significant changes to yield and with a lower cost than previous commercial diets. Test diets were commercially manufactured to mimic the nutrient profile of hybrid striped bass fillets and then fed to fish stocked in ponds at commercial rates. Results found that replacement of fishmeal with poultry by-product above 50% is feasible if the kinds and amounts of amino acids added to the diet are appropriately adjusted. The lower cost of these diets has the potential impact of significantly increasing the sustainability of marine aquaculture in the U.S. The actual impact is that some commercial growers are now field testing updated versions of these diets, and that a similar strategy for replacing fishmeal is being pursued in other marine fish culture. (NP 106: Component 6c, Growth, Development, and Nutrition, sustainable sources of nutrients, nutrient use and feed evaluation)
ANOTHER STEP ELIMINATED FROM INDOOR HYBRID STRIPED BASS PRODUCTION:
Scientists at the HKD-SNARC were able to produce hybrid striped bass fingerlings this season without feeding rotifers. Microscopic organisms called rotifers are actually the first step in a three-step process of weaning newly hatched fish (fry) from live to manufactured food. Because of their tiny mouths, it was once thought essential to begin feeding rotifers to hybrid striped bass fry before progressing to larger food like brine shrimp (Artemia nauplii) and manufactured feed. However, rotifer production is expensive, complicated, and risky. By feeding a new product on the market, microcysts of Artemia nauplii, scientists achieved good survival of hybrid striped bass fry without feeding rotifers. Eliminating the use of rotifers in hybrid striped bass production has the potential impact of tremendously reducing overall production costs and risks. (NP 106: Components 5e, Reproduction and Early Development, early life stage development and survival)
POND DYES REDUCE RISKS TO HYBRID STRIPED BASS HARVESTS:
Pond Scum, otherwise known as filamentous blue-green algae, as well as rooted aquatic plants increase risks and losses on hybrid striped bass farms by interfering with fingerling harvest. Organic dyes are sometimes applied to ponds to inhibit the growth of these undesirable plants. However, dyes can also interfere with the natural production of live foods in the pond that are needed to produce healthy stocks of fingerling fish. Scientists at the HKD-SNARC found that by timing the application of organic dyes to just before fry are stocked in the ponds, or until they are weaned to manufactured feed, reduced undesirable (blue-green) algae without interfering with live food or hybrid striped bass fingerling production. The reduction or elimination of blue-green algae from fish ponds has the added benefit of reducing the chances of producing off-flavor fish, as well. This accomplishment has the potential impact of reducing financial costs and risks associated with hybrid striped bass fingerling production. (NP 106: Component 6b Aquaculture Production Systems, production intensity)
IGF-I/IGFBPs ARE AN INDICATOR OF OPTIMUM PRODUCTION CONDITIONS:
The primary determinants of fish growth are nutrition, temperature, photoperiod, and stress that the fish are exposed to during aquaculture operations. Two of the primary chemical regulators of growth in response to these environmental determinants are insulin-like growth factors, or IGFs, and IGF binding proteins, or IGFBPs. The mechanisms through which IGFs and IGFBPs are regulated by culture conditions were studied in hybrid striped bass, and results indicate that high levels of these chemical factors are correlated with culture conditions that are optimal for growth. The potential impact of these results is that IGF and IGFBP levels in the blood may be a useful tool for optimizing culture conditions in any production scenario for hybrid striped bass. The actual impact is that this information is among the first of its kind in hybrid striped bass and lays important groundwork for future understanding of the regulation of fish growth in relation to environmental factors that will increase the profitability of U.S. fish farmers. (NP 106: Component 6b, Growth and Development, and Nutrition, tissue growth and development)
|Number of non-peer reviewed presentations and proceedings||12|
|Number of newspaper articles and other presentations for non-science audiences||1|
Davis Jr, K.B., Peterson, B.C. 2006. The effect of temperature, stress and cortisol on plasma IGF-I and IGFBPS in sunshine bass. General and Comparative Endocrinology. 149:219-225.
Davis Jr, K.B., McEntire, M.E. 2006. Effect of photoperiod on feeding, intraperitoneal fat, and IGF-I in sunshine bass. Annual Meeting World Aquaculture Society. 37:431-436.
Perscbacher, P., Ludwig, G.M. 2007. High draft rate effects of propanil and basis gold on the plankton communites and water quality of a prestocking sunshine bass Morone chrysops X M. isaxatilis, fry pond. Journal of Applied Aquaculture. 19(2):101-112.
Ludwig, G.M., Hobbs, M.S., Perschbacher, P. 2006. Ammonia, pH and plankton in sunshine bass nursery ponds: The effect of inorganic fertilizer or sodium bicarbonate. North American Journal of Aquaculture. 69:80-89.