Influence of Rainfall Seasonality on Endohelminth Parasites of Oreochromis niloticus baringoensis (Trewavas, 1983) at River Molo Inlet in Lake Baringo, Rift Valley, Kenya

This study was conducted at the inlet of River Molo in Lake Baringo, Kenya during dry and wet seasons. Dissolved oxygen, temperature, turbidity and pH were measured in-situ. Fish samples collected were preserved in a cool box then immediately transported to the laboratory for analyses. Out of 447 specimens of Oreochromis niloticus baringoensis, 340 were infected with six parasite genera belonging to three classes: Contraceacum (Nematode), Amirthalingamia (Cestode), Tylodelphys, Apharyngostrigea, Clinostomum and Euclinostomum (Trematodes). Overall, Amirthalingamia parasite had the highest (3924) followed by Tylodelphys (1509) while Apharyngostrigea had the least (13) intensity. However, Tylodelphys infected the highest number (252) of fish. During dry season, the female fish recorded the highest parasite intensity than males, whereas in wet season, nearly all males were most infected than females. Correspondence analysis showed that turbidity and dissolved oxygen had strong negative relationship with the intensity of Amirthalingamia and Tylodelphys respectively, whereas the intensity of Contracaecum, Clinostomum and Euclinostomum were strongly positively related to temperature and pH. However, Apharyngostrigea were not affected by any of the water quality parameters. Consumers are advised to cook fish properly as a precautionary measure due to the presence of zoonotic parasites. More attention is needed to address water pollution control since the study reveals that variations in physico- chemical parameters have influence on parasitic infections of fish.

Keywords: Oreochromis niloticus baringoensis, endohelminths, rainfall seasonality, intensity, pH, Temperature. Turbidity, Dissolved Oxygen.