Fish lipid contents and classes of selected fish species found in Lake Naivasha (Kenya) and the fish feeding habits of the lakes inhabitants

摘要

Consumption of marine natural products including fish is very beneficial to the health and development of the human body. These natural products provide essential nutrients that are unavailable in terrestrial plants and animal natural products. Data on the levels of lipid contents, lipid classes and fatty acid composition in the total lipid of fishes found in the fresh and marine waters of Kenya have not been determined. Thus, the aim of this work was mainly to determine the levels of the total lipid contents and lipid classes in some selected fish species of L. Naivasha, Kenya applying already known protocols with some minor modifications. The study also established the Lake Naivasha’s inhabitant fish feeding habits by utilizing a questionnaire method. The following fish species commonly caught in the Lake were studied: Common carp (Cyprinus carpio), Mirror carp (Cyprinus specularis), Largemouth bass (Micropterus salmoides) and Tilapia (Oreochromis leucosticus). These fish specimen were obtained directly from the fishermen at the Central Landing in the Lake at 00° 44.369' N and 36° 24.133' E. The results of this study indicated that total lipid content was highest in the muscle tissue of the tilapia fish, in the pyloric caecum tissue of the largemouth bass and in the liver tissues of the common carp. The lipid content results obtained here indicated that the fish specimens were lean fishes. Phosphatidylcholine (PC) was the dominant lipid class in the muscle tissue of all the four fish species. In the pyloric caecum and the liver tissues of the four freshwater fish species, phospholipids [(PC and phosphatidylethanolamine (PE)] were the dominant lipid classes in both tissues. The fish eating habit results suggested that 36% of the respondents consume fish more than once per week while only 6% do so a few times a year because of its unavailability (24%) and high cost (25%). However, results suggested that respondents are willing to consume fish more frequently if they are made more available at subsidized prices. Thus, the positive change towards the consumption of fish products can lead to a healthier citizen whose diet will be free from reliance on red meat containing high levels of cholesterol (commonly associated with terrestrial animals) to white marine meat which contain high level of omega-3 fatty acids.