The Monogenean Trematode, Gyrodactylus, A Major Constraint to African Catfish (Clarias Gariepinus), Production: A Case Study of Small Scale Fish Farms in Ibadan, Nigeria

Abstract

The gill fluke of the Gyrodactylus spp was found to be the major parasite of Clarias gariepinus in cultured conditions in Ibadan, NIGERIA. This paper describes the results of a study carried out to screen the external parasitic burden of the African catfish Clarias gariepinus in its culture environment. A total number of one hundred and fifty fish samples were collected over a period of three months from small culture ponds and tanks in Ibadan town. A brief on management practice and disease history was obtained from every farm where samples were collected. Fish were weighed and measured for their lengths. Mean values and standard deviations were calculated. Fish was then euthanized; smears of skin, fins and gill tissues were prepared and analyzed. The following parasites were recovered from the skin; Costia in 2% of sampled fish, Trichodinella in 5%, Dactylogyrus in 7%, an unidentified parasite at 5% all these each in 8% of visited farms. The gill parasite Gyrodactylus was present in 31% of screened fish and in 25% of the visited farms it then represented 46% of the total parasites recovered in this study. This parasite occurred in high incidence, its effect on the host fish with regards to the type of pathology created may present an economic threat to the stability and growth on catfish industry with serious implications for food security. Measures need then to be taken with regards to capacity development in rapid fish disease diagnosis, prevention and control.