Efficiency of various strategies to induce triploidy in Mytilus edulis in relation to their first-stage performance

ABSTRACT Recently, there is a greater interest for the development of mussel Mytilus edulis hatcheries, particularly for the production and commercialization of triploid bivalves. The aims of this study were to examine the efficiency of inducing triploid mussels by various treatments and to determine the effect of triploidy on larval development. To produce triploids, extrusion of the second polar body of fertilized eggs was inhibited by 6-(dimethylamino)purine (6-DMAP), cold-shock, or heat-shock treatments. Triploidy was detected by flow cytometry for all the treatments. Treatment with 6-DMAP was the most efficient with a rate of triploidy of 90%, followed by heat-shock (56%) and cold-shock (30%) treatments. No survival differences were observed between diploids and 6-DMAP-induced triploid larvae from the D-shape stage up to their settlement. Moreover, increased growth was observed in triploid larvae compared to diploid larvae. Overall, this study showed that 6-DMAP is a highly efficient method to induce triploidy in mussels, with triploid larvae having faster growth compared to diploid.