JOURNAL OF THE Vol. 40, No. 5 WORLD AQUACULTURE SOCIETY October, 2009 Effects of Varying Dietary Protein Levels and Feeding Frequencies on Condition and Reproductive Performance of Channel Catfish to Produce Hybrid Catfish Herbert E. Quintero 1 , Alison Hutson, Atra Chaimongkol, Allen Davis, and Rex Dunham Department of Fisheries and Allied Aquacultures, Auburn University Auburn, Alabama 36849-5419, USA Asheber Abebe Department of Mathematics and Statistics, Auburn University, Auburn, Alabama 36849-5419, USA Abstract The interspecific hybridization of channel catfish, Ictalurus punctatus, females with blue catfish, I. furcatus, males has been identified as a method to further improve production; however, lack of spawning success has affected its commercial application. To facilitate our understanding of the interaction of brood stock nutrition and reproductive performance, we evaluated the interaction of feed quality and feeding frequency. Channel catfish females were classified into two genetic groups, namely, high and low spawning. The treatments were offered during the spring season 70–90 d prior to the start of the spawning season. Induced reproduction was performed using luteinizing hormone releasing hormone analog. Condition of the fish as well as reproductive performance using spawning success, egg production, egg size, and fertilization at 48 h were determined. Changing protein level of the diet from 32 to 42% did not influence spawning, fecundity, or fertilization, but affected egg size and biochemical composition of the eggs. Increasing the feeding frequency from three to six times per week negatively affected spawning in one of the two genetics groups, did not affect egg production and egg fertilization, but had a significant effect on egg size. Older fish performed better than younger fish in terms of spawning success and egg production. The catfish industry in the USA started in the late 1960s, and has grown rapidly to become the largest segment of the aquaculture industry in the USA (Quagrainie and Engle 2002; Engle 2003). Commercial catfish pro- duction generated over 42% of the total value (462 million dollars) of aquaculture production in the USA during 2005 (USDA 2006). Since 2000, the US farm-raised catfish industry has suffered because of low prices in the market- place caused by the influx of imported fish, depressed prices for competing meats, and a weak economy (Hanson et al. 2004). These economic challenges will require developing new production technologies, market infrastruc- ture, and market development (Engle 2003; 1 Corresponding author. Hanson et al. 2004) that lead to enhanced productivity. Hybridization techniques have identified the interspecific hybrid channel catfish, Ictalurus punctatus, female × blue catfish, I. furcatus, male as the most suitable for culture conditions, because of its better growth, higher resistance to low dissolved oxygen levels, resistance to diseases, ease of harvesting, and higher car- cass yield (Dunham et al. 1987, 1990; Jeppsen 1995; Argue et al. 2003). However, reproduc- tive problems have limited its application on a commercial scale (Tave and Smitherman 1982; Dunham and Smitherman 1987). Increasing interest in developing techniques to manipulate and control hybrid production has shown a significant increase during the past 25 yr, in areas such as physiological responses, genetic aspects, artificial fertilization, and husbandry © Copyright by the World Aquaculture Society 2009 601