Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2011
Publication Date: 4/23/2012
Citation: Torrans, E.L., Ott, B.D. 2012. Effects of DO concentration in growout performance of blue catfish with comparison to channel catfish. North American Journal of Aquaculture. 74(2):273-282.
Interpretive Summary: Three controlled pond studies were conducted in 2005, 2006 and 2007 to determine the oxygen tolerance (response to hypoxia) of blue catfish Ictalurus furcatus as compared to channel catfish I. punctatus. Contrary to anecdotal reports, blue catfish perform slightly better under hypoxic conditions than do channel catfish. At a minimum dissolved oxygen (DO) concentrations ranging down to 1.4 ppm, blue catfish have slightly higher feed intake and production than do channel catfish. Feed efficiency (expressed as FCR - pounds fed/ pounds net fish production) was similar between species and was not affected by DO concentration. In addition to being valuable for the production of channel catfish female X blue catfish male hybrids, blue catfish have potential as a food fish in their own right.
Technical Abstract: Feed intake, feed conversion ratio (FCR), and production of blue catfish Ictalurus furcatus and channel catfish I. punctatus were examined in one-acre ponds maintained at either a high or low (means of 4.29 and 2.54 ppm, [54.8 and 32.4 % air saturation] respectively) minimum dissolved oxygen (DO) concentration throughout the growing season. Two additional studies were conducted examining only blue catfish in 0.25-acre ponds maintained at either a high (means of 4.43 and 4.46 ppm [56.3 and 54.9 % saturation] in the two studies) or low (means of 1.41 and 1.64 ppm [18.3 and 20.1 % saturation]) minimum DO concentration. Blue and channel catfish exhibited similar feed intake, growth, gross and net production in the high-oxygen treatment in the one-acre ponds; within the low-oxygen treatment feed intake was over 8% lower and both gross and net production were significantly lower (14.5% and 18.3% lower, respectively) in the channel catfish ponds. FCR was similar between species and was not affected by oxygen treatment. In the blue catfish studies in the 0.25-acre ponds, feed intake and net gain were significantly better both years in the high-oxygen treatments; gross and net production were significantly better in the high-oxygen treatment in 2006 and approached significance in 2007. FCRs were similar among oxygen treatments both years. Data from these and other similar controlled studies indicate that feed intake in blue catfish, although not significantly better, tends to be higher than channel catfish maintained at a similar minimum DO concentration. Feed conversion is similar between channel and blue catfish, and is not affected by minimum DO concentration within the ranges examined.