Larval Development of the Brackish Water Clam Corbicula japonica (Bivalvia: Corbiculidae), with Special Reference to Morphological Comparison with Concurrent Tidal Flat Bivalves

Abstract

Based on fertilized eggs obtained from artificially induced spawning of the brackish water clam Corbicula japonica, the larvae and post-larvae were reared for 18 days in the laboratory. Planktonic larvae of C. japonica passed through the trochophore and D-shaped larval stages (the early stage of veliger larvae), but lacked umbo larvae (the latter stage of veliger larvae), with the result that the late-stage D-shaped larvae with a developed foot settled and metamorphosed on the bottom and walls of culture vessels. To aid in the identification of the larvae of C. japonica in plankton samples and their post-larvae in benthos samples, larval and post-larval shell morphology of the clam is described and compared with that of the other bivalves dominant in Japanese estuarine waters.