THE INFLUENCE OF EXTRINSIC FACTORS IN FRESHWATER BODIES ON HELMINTH PARASITE ABUNDANCE AND DIVERSITY IN CICHLID FISHES FROM IBADAN, OYO STATE, NIGERIA

摘要

The relative patterns of helminth parasite community of cichlid fishes from freshwater bodies in Ibadan were studied in relation to physicochemical parameters and heavy metal concentration. A total of 354 Cichlids were collected at random from the catch of commercial cast and drag net during a late dry season and early rainy season. The helminth parasites recovered consisted of six trematodes and two Acanthocephalan species. Cichlids from Agodi fish farm, an artificial freshwater body had significantly highest prevalence of 68.7% followed by cichlids from Ijokodo fishing point (38.8%) and those from Eleyele fishing point (28.5%). Cichlids from Ijokodo and Eleyele sampling points, two natural water bodies, had greater parasite diversity (0.79, 0.76)richness (3.14, 2.92) and evenness (0.91, 0.88) compared with 0.20, 1.20 and 0.34 parasite diversity, species richness and species evenness respectively in Agodi fish farm. Parasite dominance and abundance was greater in fishes from artificial water bodythan in the fishes from natuiai water body. Only three trematode parasites: Phagicola longa, Clinostoimim tilapiae, and Alloglossidium corli recovered from fishes showed significant difference in prevalence (P<0.05) relative to sampling stations. Similar trend was also observed in infected intensities. The most abundant, dominant and the only helminth found outside the alimentary canal of tlte cichlid fish species was Clinostomum tilapiae. The parasites were evenly distributed in all the cichlids examined. The significance of aesthetic pollution with iron observed in this study correlated positively with the significantly high prevalence and low species diversity, richness and evenness of P. longa, C. tilapiae and A. corti. The present study shows that species abundance and diversity of parasitic helminth fauna of cichlids may be dependent on prevailing conditions, particularly management of artificial water body, which vary from one water body to another.