Reproduction of the endemic engraulid, Coilia nasus, in freshwaters inside a reclamation dike of Ariake Bay, western Japan

To examine reproduction of Coilia nasus, an engraulid endemic fish to Ariake Bay, in the freshwaters upstream of the reclamation dike of Isahaya inlet, ichthyoplankton was collected at the surface with a larva net. Eggs and larvae of this species were captured in abundance, especially in the retention basin. All eggs had reached middle or late embryonic stages, and larvae from the preflexion with yolk to the juvenile stage (4.1–39.3 mm) were found. This suggests that the freshwaters of retention basin supply spawning and nursery grounds for C. nasus.