Caligid fish parasites from the South and East coast of South Africa

English: Caligus Muller, 1785 are caligid copepods found almost exclusively on marine fish hosts. This genus is represented by more than 200 species in the oceans of the world and is the largest genus of parasitic copepods. A total of 39 species of Caligus parasites have been recorded off the coast of Africa, and 26 species are found along the South African coastline. Surveys carried out from 1992 to 1998 in Lake St Lucia and from 1997 to 1999 at De Hoop Nature Reserve and Jeffreys Bay along the coast of South Africa, revealed the presence of caligid copepods, of the genus Caligus MilIler, 1785, occurring on the body surfaces and gills of many estuarine and intertidal fish species. Four different species were collected from marine hosts namely, Caligus acanthopagri Lin, Ho & Chen, 1994, Caligus confusus Pillai, 1961, Caligus engraulidis Barnard, 1948, and Caligus mortis Kensley, 1970. The first three species mentioned were collected in Lake St Lucia, KwaZulu-Natal, on the east coast of South Africa, and C. mortis were collected at De Hoop Nature Reserve and Jeffreys Bay on the south coast of South Africa. In the present study, males of C. engraulidis and C. mortis are described for the first time and is new to science. Further studies revealed that interesting hypersymbionts were found attached to the caligids. Sessiline ciliophorans were found on both C. acanthopagri and C. engraulidis and represents a first record for South Africa. Udonella caligorum Johnston, 1835 were found on the caligid host C. engraulidis. This monogenean worm have a complicated history, for it was placed in different taxa and families since it was first described in 1835. Phylogenetic analysis as well as morphological analysis places this worm firmly as a polyonchoinean monogenean alongside the Gyrodactylidae. These hypersymbionts do not feed on the copepods and have no detrimental effects on their hosts.