Comparisons of Growth Hormone Transgenic Channel Catfish (Ictalurus punctatus), and Channel Catfish Transgenic for Gonadotropin Releasing Hormone Knockout Genes Grown in Earthen Ponds at High Density

Abstract

The objective of the experiment was to compare the growth rate and sexual maturity score of growth hormone transgenic channel catfish, transgenic sterilization channel catfish, and non-transgenic channel catfish at high density, similar to a modular catfish culture system. Fish were harvested at 4 years of age and at 5 years of age after being communally grown in the same pond. Sex-age interactions were observed. CAB (tilapia GnRH antisense transgene) females had the highest observed early body weight but were the smallest genetic type of female at final harvest. PAB (rainbow trout GnRH antisense transgenic) had the highest observed body weight at final harvest for females. GAD (goldfish glutamate decarboxylase transgene) had the highest early body weight for males. AFP (channel catfish growth hormone gene transgenic) had the highest observed final body weight and the highest observed body weight gain between years 4 and 5. Sexual maturity was highly and positively correlated with growth rate. GnRH antisense transgenic channel catfish had reduced growth rate and sexual development. Alternative genetic sterilization techniques or the current technology coupled with selection may be needed to overcome this negative pleiotropic effect.