The African monogenean gyrodactylid genus Macrogyrodactylus Malmberg, 1957, and the reporting of three species of the genus on Clarias gariepinus in South Africa
Lf. Khalil et Sn. Mashego, The African monogenean gyrodactylid genus Macrogyrodactylus Malmberg, 1957, and the reporting of three species of the genus on Clarias gariepinus in South Africa, ONDERST J V, 65(4), 1998, pp. 223-231
Three different species of the genus Macrogyrodactylus Malmberg, 1957, coll
ected from the gills and skin of Clarias gariepinus (Burchell, 1822) from t
he Middle Letaba Dam and Mokgoma-Matlala Dam in South Africa were examined
and identified. This is the first record of a species of the genus in South
Africa. The three species are M congolensis (Prudhoe, 1957)--found on the
skin, M. clarii Gussev, 1961 and M. karibae Douellou & Chishawa, 1995-found
on the gills. The last species is elevated to the status of a species havi
ng been described previously as a subspecies of M.congolensis.
The present study presents and discusses the! value of some of the taxonomi
c characters which can be used to differentiate the species of the genus. T
he shape and size of the sclerites of the haptor are found to be the most r
eliable characters. Only four species of the genus, namely M. polypteri and
the three above-named species are regarded to be valid. Three species, nam
ely M. latesi Paperna, 1969, M. anabantii Paperna, 1973 and M. ctenopomii P
aperna, 1973 are regarded as species inquirenda. Generic diagnoses, measure
ments and illustrations of the sclerites of the four valid species are pres
ented and a key for their differentiation is provided. The development of t
he gyrodactylid population on C. gariepinus during the filling of the Middl
e Letaba Dam in South Africa is discussed.