Submitted to: Journal of Fish Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/10/2007
Publication Date: 1/1/2008
Citation: Silverstein, P.S., Bosworth, B.G., Gaunt, P.S. 2008. Differential Susceptibility of Blue Catfish, Channel Catfish, and Blue X Channel Catfish Hybrids to Channel Catfish Virus (CCV). Journal of Fish Diseases. 31:77-79. Interpretive Summary: Four groups of catfish were compared for their ability to survive CCV infection. Blue catfish were by far the most resistant. Fish obtained from local fish farms were less susceptible to CCV than either hybrid catfish or a catfish strain bred at USDA CGRU.
Technical Abstract: CCV is the major viral pathogen of channel catfish. Although it accounts for only approximately 5% of reported cases of the mortality in fry and fingerlings, viral outbreaks can spread rapidly and have disastrous results. Previous reports from the literature suggest that when natural routes of infection are considered, channel catfish are the primary species affected. Both blue catfish and blue catfish x channel catfish hybrids have been reported to be refractory to infection by immersion. However, these conclusions are based primarily on one report in the literature, subsequent studies, if any, have gone unreported. However, the production of hybrid catfish has increased in recent years; in part because of their reported improved disease resistance. CCV immersion challenges were conducted to compare the resistance to CCV of juvenile blue catfish, hybrid catfish, and 2 groups of channel catfish. The blue catfish were the most resistant, exhibiting only 11% mortality, followed by the industry pool fish with a mortality of 47%, the hybrids exhibiting 63% mortality and the USDA 102 x103 cross exhibiting 68% mortality. The results demonstrated that blue catfish and hybrid catfish could be infected by immersion and that not all hybrid catfish demonstrate increased CCV resistance.