A new record of Craspedacusta sowerbii (Cnidaria: Limnomedusae) from southern Africa

Abstract

The northern hemisphere Craspedacusta sowerbii has been recorded recently from temperate regions of South Africa. Its introduction to southern Africa is thought to have occurred in the 1940s, when a number of exotic species were introduced, associated with man's interference in river catchments. A new record from Theewaterskloof Dam, Cape Province, suggests that its spread is being facilitated by inter-basin translocation of the polyp stage. Histological analysis of the gonads of medusae from Theewaterskloof impoundment showed that they were all females, supporting the hypothesis that only one sex of medusa is budded from anyone polyp colony.