Genetic parameters and genotype by environment interaction for growth traits of razor clam Sinonovacula constricta, from outdoor pond and semi-natural environment

Abstract

The razor clam, Sinonovacula constricta, is a commercially important bivalve. To date, there have been very limited quantitative genetic studies of this species, especially in different aquaculture environments. This study is the first report of genotype by environment (G × E) interactions for growth traits of razor clams from outdoor pond (OP) and semi-natural environments (SNE). Over a 2-month period, the data for shell length (SL), shell height (SH), shell width (SW), and body weight (BW) of razor clams were recorded for 1 month, and marked as Data 1 and Data 2. Phenotypic data of 1627 individual clams from 17 full-sib families were used for the analysis. The overall heritabilities (h2) for all growth traits were from low to moderate, ranging from 0.127 to 0.230. The h2 of SNE was higher than that of OP (0.243–0.423 vs. 0.101–0.285). Heritabilities for growth traits indicated that these traits could be effectively selected in both aquaculture environments. Overall, both phenotypic (rp) and genetic (rg) characteristics showed high positive correlations among the growth traits. However, the rg and rp were highly variable in OP, ranging from 0.435 to 0.973 and from 0.597 to 0.874, respectively. The rg of SL, SH, SW, and BW between the two aquaculture environments for Data 1 were 0.867, 0.682, 0.651, and 0.844, respectively. The rg ranged from 0.274 to 0.619 for Date 2. These results indicated significant G × E interactions among families at different sites. This study therefore provided optimal guidelines to select breeding programs for razor clams reared in different aquaculture environments.