Thomas K. Hill

Estimates of correlation from channel catfish (Ictalurus punctatus) sib-families reared in intensively stocked tanks showed that it is possible to predict the family influence in market body weight from body weight data taken as early as 4 weeks. Survival during the first 15 weeks was highly correlated with body weights or lengths from 4 'to 12 weeks. Food conversion during the period 20 to 40 weeks was highly correlated with body weights between 16 and 56 weeks. Correlations between survival and food conversion ratio and, also, between 4 to 12 week body size traits and either 16 to 40...

Albino and Donnal channel catfish, lctalurus puncta/us (Rafinesque), were stocked in suspended cages in a pond at densities of 11.1, 13.9 and 16.7 fish per ft3, respectively, with two replications of each. There wefe no apparent growth or sucvival differences between the albino and normal channel catfish. Mean gain/fash and mean gain/cage/day were significantly different (P 0.01) between the two higher stocking densities with both types of fish. These data indicate that a standing crop of about 15 Ib per ft of cage is the maximum which can be grown in still water ponds.

Techniques were investigated for growing rainbow trout, Salmo gairdnerii Richardson, from fingerlings to market size during the winter months in a recirculation, flowing water fish culture system where channel catfish, lctalurus punctatus (Rafinesque) are grown in summer. Trout stocked having a mean weight of 0.1 Ib had a mean weight of 0.7 Ib in approximately 100 days with a feed conversion ratio of 1.29 to I. Survival of the fish was 82%. Water quality parameters and control of parasite infestations during the culture period are also discussed.

In November, 1969, four groups of channel catfish, Ictalurus punctatus (Rafinesque), with 20 fish per group were marked and put in cages in an earthen pond at the Auburn University Agricultural Experiment Station, Auburn, Alabama. Marking methods consisted of four dyes injected and applied with a tattoo machine, two fluorescent pigments and a hot and a cold brand. The fish were sampled weekly for a period of 28 weeks and each mark was evaluated on the basis of mark retention and ease of identification. Blue latex injections, hot brands and cold brands were the most effective marks used in...