SEXUAL TRIMORPHISM IN STROMBUS-LUHUANUS LINNE, 1758 (MOLLUSCA, GASTROPODA) AT SHIRAHAMA, JAPAN

Strombus luhuanus collected at Shirahama, Japan showed sexual trimorph ism. Masculinized females were larger for all linear and weight measur ements than either males or normal females. Such females also produced more tissue to shell, indicating a greater advantage for mariculture if this characteristic can be exploited. Normal females were not large r than males as has been reported in other species of the genus Stromb us, but were found to differ slightly in shell shape. Both types of fe males had slightly more slender shells than males as indicated by widt h/length ratios.