Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/2007
Publication Date: 2/9/2008
Citation: Shawl, A., Acosta-Salmon, H., Davis, M., Cape, T., Riche, M.A. 2008. Effect of protein origin in artificial diets on growth and survival of juvenile queen conch, Strombus gigas [abstract]. Book of Abstracts Aquaculture America. p. 355. Interpretive Summary:
Technical Abstract: Aquaculture methods for queen conch have been established for several decades, however, there is a need to improve the husbandry techniques for the growout of juveniles. Previous studies have examined ideal stocking densities, substrates, and calcium needs, but the nutritional requirements are not well known. There have been several queen conch diets formulated at research institutions, all of which have produced acceptable growth rates for aquacultured animals, but low growth rates in comparison to wild juveniles. A previous study at Harbor Branch comparing the standard diet (catfish chow mixed with Ulva) with diets incorporating different macroalgas suggested that juvenile queen conch fed the macroalgae Agardhiella sp. had the highest growth rates. The purpose of the study was to determine growth and survival of juvenile queen conch fed artificial diets with relatively consistent protein compositions but varying protein sources. The Rodophyta Agardhiella sp., along with catfish chow, soy protein isolate, and fish oil were used as sources of protein. The ratio of algae:catfish chow was modified while maintaining the protein level with the use of soy protein isolate and fish oil. Juvenile queen conch were stocked at 75 conch/m2 for a total of 16 conch per replicate (three replicates), and were fed 125 mg of diet per conch each day. The percent composition of the diets was: Diet A: Catfish chow (99.5%) Diet B: Catfish chow (75%) and Agardhiella (11%), Diet C: Catfish chow (75%), Agardhiella (11%), Soy Protein (12%), Diet D: Catfish chow (60%), Agardhiella (22%), Soy Protein (15%), Fish Oil (2%), Diet E: Catfish chow (45%), Agardhiella (33%), Soy Protein (18%), Fish Oil (3%), and Diet F: Catfish chow (30%), Agardhiella (44%), Soy Protein (21%), Fish Oil (4%) The protein level for Diet A was 34%; Diet B was 31%; and Diets C-F were 38%. The lipid, moisture, energy, ash, fiber, carbohydrate, and Yttrium marker content for each diet was also determined. The juvenile conch were measured (shell length and wet weight) every six weeks. At the end of the experiment, feces were collected to determine digestibility, protein, energy, and moisture content. Preliminary results indicate highest growth rates (0.10 mm/d and 0.11 mm/d) in Diets C and D, respectively. Final results for growth, survival, nutritional analysis, and digestibility will be presented.