Genetic investigation of body morphological traits in Penaeus monodon and their relationship to shrimp production

Abstract

The black tiger shrimp (Penaeus monodon) is the second most commercially important aquaculture shrimp species in the world. In Australia, P. monodon aquaculture is a drought-proof industry and has an enormous potential for its economically and environmentally sustainable expansion. However, a significant research gap needs to be addressed for implementation of advanced breeding programs. In the first two research chapters, I reported that, (i) most published studies have focused on genetic improvement of growth and survival traits, however there are few studies on body shape and body colour traits; (ii) significant G×E was present for survival traits (rg = 0.51 ± 0.09). In the next chapters, I developed and optimized protocols for measuring morphological and body colour traits of shrimp from digital images. In the last research chapter, I performed quantitative genetic analyses of body size, shape and body colour traits. The genetic parameter estimates indicated that the body size and weight traits are moderately heritable (h2 : 0.28 to 0.36), and heritability of body shape traits were low (h2 : 0.003 to 0.09). A strong positive genetic correlation was revealed among the key body size and growth traits (rg = 0.96 to 0.99) suggesting genetic improvement of these traits can be done simultaneously. The heritability of the body colour traits ranged from 0.05 to 0.35, suggesting there is potential for genetic improvement of these traits. There was a strong genetic correlation between cooked and uncooked body colour, suggesting selection on live animals will improve the colour properties of cooked shrimp. Taken together, the findings of the current project will assist in designing future shrimp breeding programs.