Efficient induction of autotriploid bay scallop Argopecten irradians irradians with growth advantages in larvae and adults

Polyploid breeding is an effective tool for genetic improvement in aquatic species, contributing significantly to the aquaculture industry. However, the efficient polyploid induction methods have been lacking for the bay scallop ( Argopecten irradians irradians ), which holds the top position in annual scallop production in China. This study established an efficient protocol for autotriploid induction in bay scallops using cytochalasin B (CB). Through orthogonal experimental optimization and general evaluation index, the optimal induction condition was determined to be 0.5 mg/L CB exposure at 24℃ for 15 min, achieving a population-level triploid induction efficiency of 75.75 %. Observations and statistical analyses of embryo and larval development revealed that CB-induced larvae exhibited slower development rate compared to diploid larvae during the early stages, along with a bit higher malformation rate. However, in the mid- and post-umbo larval stages, CB-induced larvae showed a significant ( P < 0.05) higher growth advantage, demonstrating the benefits of polyploidy. Notably, CB-induced larvae reaching the pediveliger stage approximately two days earlier than diploid reduced seed stock production costs, highlighting the notable industrial value of this approach. Statistical analysis of growth traits in eight-month adult triploid bay scallops confirmed their significant ( P < 0.05) growth advantage over diploids in total weight (67.24 %), soft body weight (60.67 %), and adductor muscle weight (52.17 %) in October 2024, indicating a higher economic value. The adductor muscle of triploid bay scallops exhibited a faster weight-increase rate (0.12 g/day) compared to that of diploids (0.07 g/day), highlighting the growth advantage conferred by the polyploid effect. This study successfully developed an efficient triploid induction technique for bay scallops, providing valuable theoretical support for polyploid breeding and genetic improvement of this species. • An efficient method for inducing autotriploid bay scallops by CB was developed. • Triploid growth advantage in larval stage reduces the seed stock production cost. • Adult triploids exhibited a faster growth rate conferred by the polyploid effect. • The study provides a practical protocol for efficient bay scallop triploid induction.