Submitted to: International Aquaculture Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2014
Publication Date: 8/31/2014
Citation: Lafrentz, B.R., Peterson, B.C., Ourth, D.D., Shoemaker, C.A. 2014. Is there a genetic correlation between the resistance of channel catfish to Edwardsiella ictaluri and Flavobacterium columnare, and how do we get there? [abstract].International Symposium on Aquatic Animal Health. p. 94.
Technical Abstract: Two major problems in the channel catfish (Ictalurus punctatus) aquaculture industry have been high disease losses to enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri and columnaris disease, caused by Flavobacterium columnare. Methods to control and prevent these diseases include antibiotic therapy, vaccinations, and management strategies. Another approach may include selective breeding. The objective of this study was to obtain baseline information on the susceptibility of channel catfish families to E. ictaluri and F. columnare Four families of channel catfish were used: family A was randomly chosen from spawns of catfish that had not been selectively bred for resistance; families B, C, and D were families obtained following selection for resistance to E. ictaluri. All four families were challenged by immersion with both bacterial pathogens. Mean cumulative percent mortality (CPM) of the families following E. ictaluri challenge ranged from 4 to 33%. Families A and B were more susceptible to F. columnare (mean CPM of three independent challenges, 95 and 93%) than families C and D (45 and 48%), demonstrating that there is genetic variation in resistance to F. columnare. An interesting observation was the two families that exhibited the highest CPM following the F. columnare challenges had the lowest CPM following E. ictaluri challenge. Further research on larger numbers of families is needed to determine if there is any genetic correlation between resistance to E. ictaluri and F. columnare; however, such research is currently limited by the lack of a reliable columnaris disease model using well water at the Warmwater Aquaculture Research Unit. Research that has been conducted to address this limitation will be discussed.