Induced triploidy in the bay scallop, Argopecten irradians, and its effects on growth and gametogenesis

Abstract

Triploidy was induced in the bay scallop, Argopecten irradians, by treating newly fertilized eggs with cytochalasin B. Treatment for 20 min duration 10 min after fertilization resulted in 66% triploidy of scallops in the 0.05 mg/l cytochalasin treatment group and 94% triploidy of scallops in the 0.1 mg/l cytochalasin treatment group, detected by measuring the relative DNA content of scallop granulocytes using flow cytometry. Individually labelled scallops of known ploidy were grown in the Damariscotta River estuary in south-central Maine, U.S.A. from May 24 to September 15, 1982. Mean adductor muscle weight in triploid scallops was 73% greater than that of diploid controls and mean total body tissue wet weight was 36% greater. Shell inflation was significantly greater in triploids, while shell height and length were unaffected. The indexes of weight and glycogen content of the adductor muscle were significantly greater in triploids at the end of the growing season. The majority of triploid scallops failed to ripen during the summer months, while diploid scallops ripened and spawned.