Maturity stage and plasma testosterone levels are related to sperm production in blue catfish,Ictalurus furcatus.

A prediction equation for sperm production in blue catfish was developed by a forward step‐wise regression analyses based on five independent factors: body weight, total length, stage of maturation, gonadosomatic index and condition factor of individual mature blue catfish raised in earthen ponds. The stage of gonad maturity and plasma testosterone contributed significantly (P < 0.05) to the prediction equation (Sperm production per unit body weight = 2.51 × maturity ? 0.01 × testosterone ? 5.776, r = 0.62, P < 0.05). The stage of maturity was strongly associated (P < 0.05) with gonadosomatic index and sperm production. Improvements in prediction accuracy are needed to make this model a useful tool to identify higher sperm producing blue catfish to improve the efficiency of channel x blue hybrid catfish embryo production.