Location: Warmwater Aquaculture Research Unit
Title: Maturity stage and plasma testosterone levels are related to sperm production in blue catfish Ictalurus furcatus Authors
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 22, 2011
Publication Date: January 9, 2013
Citation: Chatakondi, N.G., Davis Jr, K.B. 2013. Maturity stage and plasma testosterone levels are related to sperm production in blue catfish Ictalurus furcatus. Aquaculture Research. 44:161-166. Interpretive Summary: The inability to predict testes development and sperm production in blue catfish coupled with late maturation incur significant costs to the farmer associated with maintaining blue catfish males in hybrid catfish production. Sperm production can be predicted from a linear combination of stage of gonadal maturity and concentration of plasma testosterone levels with a low (r2=0.39) level of prediction. Lower sperm producing blue catfish males can be screened based on the prediction model and also suggest the needed number of blue males to be sacrificed based on the number of eggs to be fertilized.
Technical Abstract: Recently, the channel catfish, Ictalurus puntatus' X blue catfish, I.furcatus ' F1 hybrid has demonstrated good potential for commercial production compared to the commonly raised channel catfish. Efforts by researchers and commercial producers in the last 40 years have improved hybrid fry production; however little research has been conducted related to improving sperm characteristics of the blue catfish, the male parent, blue catfish. Body weight, length, stage of maturation, gonadosomatic index, condition factor and blood plasma levels of testosterone in 114 individual mature blue catfish of 5 to 8 years in age were examined as predictors of sperm production. Sperm production in blue catfish exhibited a linear relationship with the stage of gonadal maturity and plasma testosterone (y=-5.776+2.51*stage of maturity – 0.01*testosterone, r2=0.39, p<0.03). Other variables measured were not related to sperm concentration (p>0.05). Improvements in prediction accuracy are needed to make this regression model a useful tool for predicting sperm production in blue catfish to improve the efficiency of hybrid catfish production.