COMBINING ABILITY OF CHANNEL CATFISH Ictalurus punctatus FEMALES AND BLUE CATFISH Ictalurus furcatus MALES FOR TOLERANCE OF LOW OXYGEN.

Catfish are the backbone of the aquaculture industry in the United States accounting for the majority of finfish production. The main species raised is channel catfish but that is rapidly changing as many farmers are adopting the hybrid catfish due to its increased performance and disease resistance. However, there are large gaps in knowledge regarding disease resistance of hybrid catfish. Enteric septicemia of catfish (ESC) is one of the two most common bacterial infections in catfish industry which results in large economic loss annually. Full-sib and half-sib families were compared for resistance to Edwardsiella ictaluri the causative agent of ESC and for tolerance to low oxygen. Family variation was observed and general and specific combining abilities are being calculated. These results will guide catfish genetic improvement programs as this will determine whether selection for channel catfish dams and/or blue catfish sires will allow production of better performing hybrids.