Genetic parameter estimates for growth and non-growth traits and comparison of growth performance in sea cages vs land tanks for yellowtail kingfish Seriola lalandi

The aquaculture of yellowtail kingfish Seriola lalandi, is now expanding worldwide. Production is conducted in two very different types of commercial facilities: predominately in sea cages in Australia, Mexico, Chile and Hawaii; and in indoor facilities in Europe. With expansion, there is concordant commercial interest to develop genetically improved stocks for production. However, there is a great paucity of genetic information about this species. Knowledge gaps include accurate genetic parameter estimates (i.e., from large sample sizes) that are essential to develop accurate and efficient selection indices. Specifically we require accurate information on non-growth traits (such as parasite load and deformities) and their correlations with growth traits (body weight and fork length), and information on any genotype by environment (G × E) interactions between the two major growing systems to determine whether a single or multiple selection programs are required. Here we address all these fundamental genetic knowledge gaps and provide, for the first time: relatively accurate genetic parameter estimates based on approximately 1400 genotyped and phenotyped animals; and preliminary tests for G × E interactions between growth in sea cages vs land tanks. The heritability estimates were moderate and significant (0.42 ± 0.10) for growth traits, whereas heritability estimates for non-growth traits were low (0.01-0.06). The genetic correlation between body weight and fork length was positive and close to one (0.98); in contrast, the correlation between growth traits with occurrence of fluke and deformity were not significant. The genetic correlations for growth traits between two culture environments were high (0.92-0.97); they were however, associated with large standard errors. In summary, the new set of genetic parameters obtained from this study provide accurate information that is essential to develop genetically improved stocks of yellowtail kingfish for commercial production.