CO-PARASITISM AND MORPHOMETRICS OF THREE CLINOSTOMATIDS (DIGENEA: CLINOSTOMATIDAE) IN Sarotherodon melanotheron FROM A TROPICAL FRESHWATER LAKE

In ever competitive environment of nature, evolution of most attributes of an organism - anatomy, physiology, and behaviour are determined by the environment through selection. The same is the microhabitats of Sarotherodon melanotheron where three Clinostomatids; Clinostomum tilapiae, Clinostomum complanatum, and Euclinostomum heterostomum, were recovered from Opi Lake (GPS N06.75275 * , E007.49104 * ), were studied from (November 2007– October 2008) using multiple fishing gear techniques; cast nets, hook and line, and seine nets (150 mm – 200 mm), showed significant difference (p < 0.05) in all other anatomical parts but the distance between oral and ventral suckers. The prevalence was low; (20.8 %) was recorded in C. complanatum, (6.4 %) in E. heterostomum and (21.1 %) in C. tilapiae. But mean intensity was high which was suggestive of heavy parasite burden; C. complanatum (2.7), C. tilapiae (5.8) and E. heterostomum (5.1). In the rank-abundance curve for parasite communities C. tilapiae was more abundant than the other two species. Differential parasitic implications was due to selection for relatively better adaptiveness to host’s microhabitats, more population size, better host location,  and larger body size. Consequently, this resulted in a trade-off between larger morphometric parts and population size among the parasites.