Comparative study of African catfish parasites from cultured and natural habitats

Background The study was conducted to compare parasitic loads of Clarias gariepinus from cultured and natural habitats. A total number of 80 live adults (200–799 g) C. gariepinus comprising of 20 each were randomly obtained from two cultured habitats (ponds) and two natural habitats (rivers). In the laboratory, these fish were all examined for the presence of parasites. Their sexes were identified while the lengths and weights were measured and recorded prior to dissection. The parasites observed were also identified using morphological characteristics. Results Out of the 80 C. gariepinus sampled, 43 (53.75%) were infected and a total of 409 parasites comprising of 141 (34.47%) ectoparasites and 268 (65.53%) endoparasites were observed from the infected fish. The prevalence of parasitic infection in cultured and natural habitats was 20% and 33.75%, respectively. The results showed that there was a significant difference ( P < 0.05) in parasitic infection of C. gariepinus obtained from cultured and natural habitats. Parasitic loads were observed to be significantly higher in natural habitat (33.74% and 26.16% for river A and river B, respectively) compared to cultured habitat (20.54% and 19.55% for pond A and pond B, respectively). The prevalence of parasites in relation to sexes of C. gariepinus was not significantly different ( P > 0.05) for both habitats. It was also noted that catfishes with body weight 500–599 g had the highest prevalence (100%) both in cultured and natural habitats. Conclusions The study showed that the parasite loads were more in C. gariepinus obtained from natural habitat compared to those obtained from cultured habitat. It is therefore recommended that the sanitary conditions under which fishes are reared in fish pond should be improved and fish stocked from natural habitats or unscreened ponds should be quarantined to eliminate and treat possible parasitic infection before introducing them into other fish ponds.