An Intermediate Form between Two Venerids, Gomphina melanaegis ROMER and G. veneriformis (LAMARCK), Found in the Western Japan Sea Shores

Abstract

In October 1977, an intermediate adult form between Gomphina melanaegis introduced commercially from Kashima-ura, the Pacific coast of Honshu, and native G. veneriformis was found on sandy beaches in the Hashi District, Shimane Pref. G. melanaegis and G. veneriformis can be distinguished from shell-sculpture found on their umbonal region when young. The characteristic of the intermediate form coincides with that of G. veneriformis, though the shape and size somewhat resemble those of G. melanaegis. Therefore, the intermediate one was considered to be a hybrid between both species developed under the natural environment.