Timing of Glochidia Release in Pronodularia japanensis (Bivalvia: Unionidae)

Abstract

The diel rhythm of glochidial release from gravid mussels of the species Pronodularia japanensis was investigated in the laboratory. Gravid mussels discharged glochidia principally at night, with a peak in the early part of the night. Glochidia formed a mass by entangling their larval threads.