Students in the determinants of the parasites` community structure of the clariid fisheries in lake Victoria

Abstract

The clariids are catfishes that belong to the suborder Siluroidea and inhabit diverse habitats, are able to traverse long distances and are omnivorous in feeding habits. These feature parasite fauna. This study was s predispose the clariids to infection by a diverse parasite fauna. This study was design to investigate the factors that determine the structure. Specifically, the study investigated the phylogenetic relationships among the clariid species and their most common parasites based on comparative morphology and molecular characters. The study further analysed the host-parasite communities. The use of morpho morphometrics with multvariate statistics revealed that Clasias gariepinus is related to Clasias liocephalus, as is Clarias warneri to Clarias Aluaudi. phylogenetic analysis based on mitochondria cytochrome gene suggested the same relationship as in morph metric analysis. Molecular phylogenetic revealed that Heterobranchus longifilis is the oldest clariid in Tanzania and C. gariepinus is oldest in the Lake Victoria basin. Clariid species are estimated at 500,000 years old and 12 years old. Phylogenetic analysis of the metazoan parasites of clariid fishes based on the nuclear 18S rDNA gene delineated the parasites into their respective lineages. Host-parasite relationship using ``a strict co evolutionary`` constrained trees strongly suggested that the clariid fish hosts and their parasite fauna did not coevolve. Hence, it is concluded that parasite communities in clariid fishes studied are structured by host-parasite ecological factors. The host parasite attributes and ecological correlates of parasite species richness are therefore discussed.