Spawning and Hatchery Technology to Improve Hybrid Catfish Fry Production

Catfish production, 300 million kg annually, is 70% of all US aquaculture production. In many impoverished areas of the South, this industry is critical for the economic viability of communities. Imports of fish products resulted in a $10.7 billion trade deficit in 2000. Imported catfish now threaten profits of catfish farms. Impediments to sustainability and competitiveness such as, slow growth, inefficient feed conversion, mortality from disease and the associated use of chemicals, loss of fish from low oxygen, inefficient harvesting, inefficient use of land space and processing waste can be diminished by utilization of the channel X blue catfish hybrid. This hybrid exhibits increased growth (20-100%), feed conversion efficiency (10-20%), disease resistance and survival (10-50%), tolerance of low dissolved oxygen (50-100%), harvestability (100%), book-and-line vulnerability (100%) and carcass yield (10%). This hybrid would revolutionize catfish production, but behavioral reproductive isolating mechanisms prevent consistent large-scale production of this hybrid despite large demand. Recent research indicates induced spawning with LHRH, brood stock nutrition and controlling fungus in the hatchery may be the keys to successful hand stripping for production of hybrid embryos. The efficiency of hybrid embryo production needs to increase to a competitive level by identifying the most economic technology to increase hatch of eggs. Objectives are to determine the seasonal variation of dosages of LHRH needed to efficiently induce females, determine proper nutritional preparation of brood stock and determine the best treatments to control fungus. Results from treatment variables will be compared economically to determine the direction of Phase II research to solve this problem.