SPHAEROMATID ISOPODS FROM THE SWAN RIVER, WESTERN-AUSTRALIA - DIVERSITY, DISTRIBUTION, AND GEOGRAPHIC SOURCES

Seven species of. sphaeromatid isopod colonize the shallow littoral zo ne of the Swan River Estuary. Their distribution relates closely to th e hydromorphology of the estuary and even reflects small scale interan nual changes in salinity. The high diversity can partially be explaine d by the heterogeneous environment and the establishment of introduced species. Possible sources of the sphaeromatid fauna are discussed usi ng the criteria of a test proposed by Chapman & Carlton (1994) to iden tify introductions.