Changes of heritability and genetic correlations in production traits over time in red abalone (Haliotis rufescens) under culture

Abstract

Red abalone Haliotis rufescens is one of the most valuable mollusks in the international market, but it has a low growth rate. A breeding program is being developed to increase its growth rate in Chile. We estimated the changes in direct heritability (h2), maternal/common environments heritability (m2) and genetic correlations (rG) of growth traits (shell length and width, total mass, flesh mass and foot protein as an indicator of meat quality) measured during 2 years (every 4 months) from the juvenile stage (27 months) to the adult harvesting age (51 months), in 60 full‐sib red abalone families. Heritabilities for growth traits measured in juveniles and young adults (27–35 months of age), were low (0.07–0.17) and not significant. Initial low h2 were associated with significant amounts of maternal/common environmental effects (m2 = 0.4). In young adults and abalone near the harvest age (39–51 months of age) h2 were much higher (0.32–0.75). These results emphasize the importance of multiple estimations of h2 over time. Among meat quality traits, only the h2 for the flesh mass for adults at harvesting age was significant (0.15). We observed strong positive rG (>0.9) between shell sizes (easy to measure) and total and flesh masses (trait more related to market value than shell sizes but harder to measure) for adults at harvesting age. Thus, if the 5% largest 51 month old abalone were selected from the population as broodstock we expect a positively correlated response on flesh mass of 23.4%.

Family‐level variation in early life‐cycle traits of kelp

“…, Brokordt et al. ), highlighting the importance of estimating heritability through different developmental stages.…”

“…It is not known how these results for the early life-cycle stages translate to macroscopic adults. However, in abalone and other shellfish, heritabilities of growth traits become stronger as the organism ages while phenotypic expression due to maternal and environmental effects are more pronounced in juveniles (Coman et al 2010, Brokordt et al 2015, highlighting the importance of estimating heritability through different developmental stages. Tests of significance: *P < 0.05; **P < 0.01; ***P < 0.001.…”

Anti-predator response of Haliotis tuberculata is modified after only one generation of domestication

“…Numerous studies have shown that growth is a heritable trait in Haliotis spp. (Lucas et al 2006, Robinson et al 2013, Roussel et al 2013, Camara & Symonds 2014, Brokordt et al 2015, although the estimation of heritability varies widely among species and for the same species. Neverthe-less, improved growth of the F 1 generation is not always observed in spite of the fact that growth in weight is a heritable trait.…”

An Annotated Genome for Haliotis rufescens (Red Abalone) and Resequenced Green, Pink, Pinto, Black, and White Abalone Species

“…1), which grows quickly and reaches a large size in culture; popular in the US market, they are also one of the most valuable species in the mollusc industry (Aguilar-Espinoza et al. 2014; Brokordt et al. 2015).…”