Enhanced survival and growth in the selectively bred Chrysophrys auratus (Australasian snapper, ta over line mure)

We report results from a comparison of a wild (F1) and a selectively bred elite (F3) strain of Chrysophrys auratus (Australasian snapper, ta over bar mure), a species that has been selected for enhanced growth using genomics-assisted breeding selection. Populations (n = 100) of each strain were cultivated in replicated tanks over 39 days and fed for 8 h/day at two feeding frequencies (hourly and bihourly). Survival, feed intake, weight gain and feed conversion ratio (FCR) were measured as the fish grew from approximately 5 to 15 g at a mean temperature of 18.6 degrees C. The selectively bred strain exhibited significantly improved performance over the wild strain in all measured traits. The F3 strain exhibited almost 100% survival, compared with 85% survival in the wild strain. The weight gain of the selected strain was 28-30% higher and FCR improved by 33-73%. In addition, intra-cohort variation was considerably lower for the F3 strain, and these fish were less sensitive to the effects of feed frequency. Feed intake was not substantially different between strains, and breeding gains in this species seem to be underpinned by substantially improved feed conversion. The results of this study indicate that the genomics-assisted selective breeding of C. auratus has significant potential to address production cost and effi-ciency concerns hindering the development of farming of this species in Australasia.

Automated summary

This study compares a wild strain and a selectively bred elite strain of Chrysophrys auratus. The results show that the selectively bred strain exhibits significantly improved performance in all measured traits, including survival rate, weight gain, and feed conversion ratio. In addition, the selectively bred strain has lower intra-cohort variation and is less sensitive to feeding frequency. This suggests that genomics-assisted selective breeding has great potential for the farming of C. auratus in Australasia.