Effect of three triploidy induction methods on the growth and survival of larvae and post-larvae of the Caribbean scallopArgopecten nucleus

Abstract

Argopecten nucleus is a small scallop from the Caribbean Sea and a relatively new species for aquaculture. One of the key challenges to develop the farming operations for this species from the current pilot scale to commercial level is to improve its harvest size. In this study, we tested three different methods for triploidy induction. Additionally, the effect of these protocols on survival, developmental rate and size of larvae and post-larvae were assessed. Three different mechanisms to stimulate the inhibition of the release of the second polar body were tested; (1) cold shock (18°C); (2) 6-dimethylaminopurine (6-DMAP); (3) cytochalasin B (CB) and (4) dimethylsulphoxide (DMSO). The treatment with 6-DMAP yielded the highest percentage of triploid larvae (39%). The survival and development rate, however, were higher in non-treated larvae (control) than in the treatment groups. Interestingly, larvae from CB and the DMSO control groups exhibited lower growth rates in length than those from control and the other two treatments. No influence of the triploidy induction treatments was observed on post-larvae survival, but the size of post-larvae was larger for the cold shock treatment and DMSO control group. Our results indicate that the use of 6-DMAP has the greatest potential to produce triploid larvae of A. nucleus without affecting negatively growth and survival of post-larvae.