First generation inbred channel catfIsh (Ictalurus punctaius) were produced from full brother-sister matings to be compared in growth response to various temperature regimes to a control family produced from the same base population. Temperature regimes involved: (1) constant 22 C well water for 28 weeks, (2) well water heated to 27 C for 20 weeks and not heated (22 C) for the subsequent 8 weeks, and (3) ambient temperature of a 2-ha reservoir. Results indicated that genetic divergence between 2 lines was associated with a differential response to temperature regime. Weekly weight gain and total length growth were the highest in ambient temperature, intermediate in 27C, and least in 22 C temperature. Inbred catfIsh gained more than the controls in all 3 temperatures.
