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Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/22/2013 Publication Date: 1/24/2014 Citation: Bosworth, B.G., Waldbieser, G.C. 2014. General and specific combining ability of male blue catfish Ictalurus furcatus and female channel catfish I. punctatus for growth and carcass yield of their F1 hybrid progeny. Aquaculture. 420-421:S29-S35. Interpretive Summary: U.S. aquaculture production of channel catfish female (Ictalurus punctatus) x blue catfish male (Ictalurus furcatus) F1 hybrids has increased substantially due to the hybrid’s improved growth, survival, carcass yield and ease of harvest compared to the more commonly farmed channel catfish. However, information on development of breeding programs to further improve hybrid catfish performance is lacking. Matings were made between female channel catfish and male blue catfish using a factorial design (all males mated to all females, all females mated to all males), and the resulting hybrid catfish offspring were grown in communal ponds and then measured for growth and carcass yield. Parentage of offspring was assigned through the use of DNA markers. Analysis of the growth and carcass yield data indicated presence of substantial genetic effects of parents on offspring performance. Female parent explained the majority of the variation in offspring performance, male parent accounted for a moderate amount of the variation in offspring performance and specific female parent x male parent combinations were relatively unimportant in explaining variation in offspring performance. Therefore, it will be possible to improve hybrid catfish growth and carcass yield by selecting superior female channel catfish and male blue catfish parents. The data indicate that searching for specific male x female parent combinations is not necessary, therefore making selection of parents that produce superior hybrid offspring a more straightforward and efficient process. Technical Abstract: U.S. aquaculture production of channel catfish female (Ictalurus punctatus) x blue catfish male (Ictalurus furcatus) F1 hybrids has increased substantially due to the hybrid’s improved growth, survival, carcass yield and ease of harvest compared to the more commonly farmed channel catfish. However, information on the genetic architecture underlying phenotypic variation in the hybrid which is needed to develop an efficient genetic improvement program is lacking. Progeny from two separate factorial matings between male blue catfish and female channel catfish (10 males x 7 females and 12 males x 5 females, respectively) were grown communally in earthen ponds and measured for carcass yield and weight at approximately 520 days post-hatch. Parentage of progeny was assigned by inheritance of microsatellite genotypes. Progeny from 118 full-sib families, within 12 maternal half-sib and 22 paternal half-sib families, were measured for harvest weight (n=1288) and carcass yield (n=1101). Variance component estimates associated with dams (dam general combining ability and heritabilites based on dam half-sib families) were high, variance associated with sires (sire general combining ability and heritabilites based on sire half-sib families) were intermediate, and variance components associated with the dam*sires interactions (specific combining ability) were low for carcass yield and harvest weight. Data indicate that the genetic variance for carcass yield and harvest weight of F1 hybrids was primarily additive. Selection for improved carcass yield and growth based on additive genetic merit of blue catfish male and channel catfish female parents should be effective for improving performance of hybrid progeny. |
