Genetic parameters for growth and fillet traits in Asian seabass (Lates calcarifer, Bloch 1790) population from Thailand

Abstract

This study aimed to estimate genetic parameters for growth and fillet traits of Asian seabass using REML method and Bayesian approach via Gibbs sampling. Seabass fry were produced by mass spawning of 20 males and 24 females and reared as mixed families. At 120 days post hatch (dph) 3000 fish were measured, fin-clipped and marked with PIT tags in the body cavity and distributed equally into two earthen ponds. During grow-out, fish were measured at 270 dph. At 390 dph, fish were harvested, measured and filleted by skilled processors. Pedigrees were reconstructed using eleven microsatellite loci. A total of 1750 fish used in the analysis were progeny of 16 sires and 18 dams. A multivariate animal model with the fixed effect of earthen pond was used to estimate variance components. Heritability estimates for body weight (BW) were low to moderate and increased with age. The REML (and Gibbs sampling) estimates were 0.06 (0.26), 0.16 (0.31) and 0.45 (0.48) for BW120, BW270 and BW390, respectively. Heritability for total length (TL) followed the same trend, with REML (and Gibbs sampling) estimates of 0.07 (0.26), 0.11 (0.28) and 0.37 (0.40) for TL120, TL270 and TL390, respectively. The REML and Gibbs sampling estimates for fillet weight were high (0.50 and 0.52) and low to moderate for fillet yield (0.16 and 0.31). Genetic correlations were high and close to unity between BW at different ages and fillet weight (0.85–0.98). Results indicate a selection potential in this Asian seabass population and that use of weight at younger age (120 dph) as a selection criterion would result in increased body weight at harvest (390 dph) along with increased fillet weight.