Evaluation of Endoparasites in <i>Oreochromis aureus, Amia calva</i> and <i>Clarias gariepinus</i>, in Ase River, Delta State, Nigeria

Abstract

Parasites constitute a major problem for fish health and their prevalence hamper fish growth and productivity by increasing their  morbidity and mortality. Fish endoparasites are often associated with zoonotic disease in humans. The aim of this study was to determine  the endoparasitic prevalence and feeding habits of Oreochromis aureus, Amia calva and Clarias gariepinus, in Ase River, Delta  State, Nigeria. Atotal of 104 fish comprising of 40 O. aureus, 21 A. calva and 43 C. gariepinus were collected from seven locations of  the river during dry and wet seasons, for parasitological investigations. The livers, gills, muscles, small and large intestines of fish  specimens were examined, and the sex determination was done by physical observation of the genital papilla, which appeared long in  males and reddish round in females. From the specimens, 96 (92.3%) had 191 overall endoparasitic loads. The highest and lowest  percentage abundance of 51.18% and 13.08% were recorded in Locations 1 and 4 had respectively. Of the 96 infected fish, 29 (29.8%) were  male and 68 (70.1%) female, indicating a much higher infection rate in females. On prevalence abundance across species, A. calva  was highest with 21(100%). C. gariepinus was 40 (93.0%) and O. aureus was least with 35(87.5%). The study also identified a total of 21 endoparasites in five taxonomic groups; Protozoans (32.46%), Nematode (38.74%), Annelid (3.66%), Trematode (15.70%) and Cestode  (9.42%). The mean intensity of parasitic load showed 58.6, 37.0 and 31.6 to be moderately, highly and slightly affected. ANOVA result on  prevalence indicated a significant distribution of endoparasites across specimens (P<0.05; P=0.001). Considering the effect of parasites on  fish morbidity and mortality, human food-borne zoonoses, there is need for the communities and industries on the riverbank to  adopt right policies for water pollution control.