A Survey of The Endo-Helminths Infecting Nile-Tilapia And Nile Perch In Winum Gulf of Lake Victoria Kenya

Abstract

Kenya’s population was reported as 38.6 million during 2009 census and is currently estimated at 46.5 million, increasing at a rate of 2.7% annually. Therefore, there is need for more food sources to feed the ever increasing population. The Lakes and Rivers account for more than 96 % of the total fish production in Kenya. The annual fish production is estimated to be 200,000 metric tons (mt), accounting for 4.3% of the total agricultural production and this earns the fishermen about Kshs 4-7 billion in foreign exchange thus contributing to poverty alleviation. However, parasitic diseases of fish seem to be one of the major problems confronting the fish industry. Fish infestations lead to serious consequences especially to the nutritive devaluation of the fish, morbidities, mortalities, and some are zoonotic. The government of Kenya has in the recent past put emphasis on fisheries as an important sub-sector with potential to generate incomes for the households but also creates employment to a significant proportion of people living around lakes and seashores. In short it provides a source of livelihood to a significant proportion of the population. The fisheries sector contributes 0.5 % of the GDP of Kenya’s economy. The aim of this survey was to study endo-helminths infecting Nile tilapia, Oreochromis niloticus and Nile perch, Lates niloticus in Winam Gulf of Lake Victoria, Kenya. A total of 320 fish, comprising of 151 O. niloticus and 169 L. niloticus were collected twice a week for a period of three months (March-May, 2016) using beach seine, towed by a canoe. The fish were transported alive to Egerton University where they were killed humanely before necroscopic examination. Using routine necropsy and parasitological examination procedures, all fishes were examined for the presence of parasites. A total of 10 endo-helminths were identified from O. niloticus, while 6 helminths were identified from L. niloticus. On the other hand, an infection rate of 75.5 % (O. niloticus) and 16.6 % (L. niloticus) were obtained from this study. There were no significant differences between the parasites infecting O. niloticus and those that infect L. niloticus (student t-test p>0.05). There were weak correlations between the condition factor and endo-parasites abundance, which were not statistically significant (p>0.05). With regard to distributions, some parasites were more abundant in O. niloticus than in L. niloticus. Based on the findings of this study, infections of some endo-helminths parasites such as Tylodelphys sp. and Acanthosentis tilapiae need interventions designed for their control. Despite low occurrences of most helminths parasites, it should be noted that some parasitic infestations can negatively affect fish production