Redescription of Dactylogyrus acanthobramae Paperna, 1961 (Dactylogyridae: Monogenea)

Dactylogyrus acanthobramae Paperna, 1961 is redescribed and its relationship with other species of this genus is discussed

Occurrence of Neodiplozoon polycotyleus Paperna, 1973 (Diplozoidae: Monogenea) in cyprinid fish in South Africa

Neodiplozoon polycotyleus Paperna, 1973 is recorded from Barbus marequensis Smith, 1841, Barbus neefi Greenwood, 1862, and Barbus trimaculatus Peters, 1852 in the Limpopo River System, Northern Province, South Africa.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

The African monogenean gyrodactylid genus Macrogyrodactylus Malmberg, 1957, and the reporting of three species of the genus on Clarias gariepinus in South Africa

Three different species of the genus Macrogyrodactylus Malmberg, 1957, collected from the gills and skin of Clarias gariepinus (Burchell , 1822) from the 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 having been described previously as a subspecies of M. congolensis. The present study presents and discusses the value of some of the taxonomic characters which can be used to differentiate the species of the genus. The shape and size of the sclerites of the haptor are found to be the most reliable characters. Only four species of the genus, namely M. polypteri and the three above-named species are regarded to be valid. Three species, namely M. latesi Paperna, 1969, M. anabantii Paperna, 1973 and M. ctenopomii Paperna, 1973 are regarded as species inquirenda. Generic diagnoses, measurements and illustrations of the sclerites of the four valid species are presented and a key for their differentiation is provided. The development of the gyrodactylid population on C. gariepinus during the filling of the Middle Letaba Dam in South Africa is discussed.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

A new Dactylogyrus species (Dactylogyridae: Monogenea) from Enteromius mattozi, Cyprinidae, at Piet Gouws Dam, South Africa

Enteromius mattozi Guimaraes, 1884, a popular eating fish among local people, were examined for monogenean parasites as part of a larger study to ascertain the feasibility of establishing aquaculture production in Limpopo, South Africa. In this study a new monogenean parasite of the genus Dactylogyrus was collected from the gills of E. mattozi, and described. It differs from known species of this group in the shape, size and structure of the heavily sclerotized vaginal prop. The proximal end of the vaginal prop has three layers similar to stacked funnels of decreasing sizes leading into a tube. The male copulatory organ is also much larger and robust than those of related species. The name Dactylogyrus mattozii is proposed for this new species.Keywords: aquaculture, Cyprinid, ectoparasite, first record, freshwater fish, monogenea

Aspects of the pathology of Lamproglena clariae (Copepoda: Lernaeidae) on gills of Clarias gariepinus from the Vaal River system, South Africa

Lamproglena clariae attaches to gill filaments of Clarias gariepinus,penetrates the gill tissue and consumes blood. Hence, the purpose of this study was to investigate the mechanical damage caused by this parasite on gill filaments of the host. Infestation intensity and haematocrit values of fish blood were determined and correlated. Fish were killed, gills dissected out and observed with a dissection microscope. Gill filaments with adult females in situ were fixed in a solution of alcohol, formaldehyde and acetic acid and preserved in 70% ethanol. Fixed specimens were studied by histological examination following staining with Heidenhein’s azan solution. Gross morphology revealed varying degrees of swelling of gill filaments near the attached specimens of L. clariae.Epithelial hyperplasia, resulting in fusion of gill lamellae and necrosis of the host tissue in the vicinity of the parasite were revealed through histological examination. No correlation was evident between the infestation intensity and fish haematocrit values. Although results showed that L. clariae causes localized infestation, high intensity of infestation may be detrimental to the fish. Hyperplasia of epithelial tissue resulting in fusion of lamellae would result in restriction of air passages and thus hinder the process of respiration of the host.Keywords: Lamproglena clariae, Clarias gariepinus, Copepoda, gill parasite, patholog