Premium
Diseases of the African estuarine catfish Chrysichthys nigrodigitatus (Lacépède) from the Cross River estuary, Nigeria
Author(s) -
Obiekezie A. I.,
MÖer H.,
Anders K.
Publication year - 1988
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1988.tb05354.x
Subject(s) - biology , estuary , catfish , fishery , population , aquatic animal , veterinary medicine , fish <actinopterygii> , medicine , demography , sociology
A survey based on monthly sampling of commercial catches was carried out in the Cross River estuary in 1984 and 1985 to determine the extent of parasitization and occurrence of externally visible lesions on the bagrid catfish Chrysichthys nigrodigitatus. Infections with the following parasites were encountered: Henneguya chrysichthyi (32%), Protancylodiscoides chrysichlhes (77%). Siphodera ghanensis (4.2%), Aspidogaster africanus (0.1%), Hysterothylacium larvae (64%), Nerolica orbignyi (1.5%), Ergasilus lalus (27%), and Chonopeltis brevis (0.02%). A new kind of epidermal papilloma was found and is described. On a yearly average, less than 0.5% of the catfish population was affected by either skeletal deformities or skin ulceration. Fin rot was observed from December to May, reaching a prevalence of 79% in February. Gill myxozoosis due to Hemwguya chrysichthyi is considered the most important parasitic disease of the fish, occurring throughout the year with a maximum prevalence of 76% in October. Results of the study are discussed in the light of a projected intensive cultivation of the fish in the extensive estuaries and lagoons bordering Nigeria's coastline.