Parasites of Clarias gariepinus obtained from culture and wild specimens of Onitsha urban stretch of River Niger. Amambra State, Nigeria

Abstract

Parasites recovered from randomly-selected specimens of Clarias gariepinus, obtained from artisanal fishery landings of River Niger at Onitsha Urban were studied. They were compared with pooled C. gariepinus specimens from two private fish farms at Onitsha Urban, Anambra State, Nigeria. The total number of fish host dissected during this investigation was one hundred and sixty. Eighty specimens were drawn from the wild and culture systems, respectively, at fortnightly interval between April to August, 2006 of the one hundred and sixty fish hosts examined, eight specimens each were studied from the wild and culture respectively. Similarly, thirty-two males and forty-six females were selected respectively for the two group studies. From the culture milieu, fifty-two were infected with one or more parasite species. The wild population presented with twenty four cases of various parasites were recovered from the liver, mouth, brain, gills, stomach and fins. Seventy-nine parasites were recovered from the wild affecting the same body areas, except that Ergasillus sp. and Argulus sp. respectively affected the fills and fins more. No significant difference was recorded in the level of parasitic infection among the two groups (P>0.05) and amongst the host males and female fish hosts. The parasite burden showed no significant differences across the selected age groups of the wild study. However, notable difference was recorded between adults, sub-adults and juveniles of the culture and wild sets studied. The economic implication of these parasites to aquaculture is noted.

Key word: Parasites, Clarias gariepinus, wild culture Onitsha Urban, River Niger.