Abstract
This study was performed to clarify the spatial variation of habitat of Corbicula bivalves (C. japonica and C. leana). A series of field investigations were performed in the Kiso River estuary, in October – November, 2012, with particular references to the existence of a series of groins. We compared the differences of water environment, substrate and diet variables in longitudinal and transverse directions (Two-way ANONA) to grasp the habitat characteristics in different landscapes. Furthermore, correlation and multiple regression analyses for their densities and biomass were applied to clarify the crucial environment variables. As the results, it was clarified that salinity and water depth could be the controlling factors for the biomass of C. japonica, whereas the sediment and salinity factors would effect on promoting the biomass of C. leana and the density of C. japonica.
