Gametogenesis and growth of induced triploid scallops Chlamys nobilis.

Triploids were induced in the scallop, Chlamys nobilis, by treating the fertilized eggs with cytochalasin B (0.5mg/l) or hydropressure (200kg/cm2). The highest percentage of triploid was 71.4% in 0.5mg/l CB treatment. When diploids were in spawning period, most triploids had spermatocytes or developing oocytes. However, neither matured oocytes nor spermatozoa were observed in triploids. Although at 9 months of age no quantitative characters differed significantly between diploids and triploids, at 14 months the shell width and meat weight of triploids were greater than those of diploids. The relation between gametogenesis and growth in triploid scallops is discussed in this paper.