Characterisation of fish oils of mukene (Rastrineobola argentae) of Nile basin waters – Lake Victoria, Lake Kyoga and the Victoria Nile River.

Abstract

Mukene (Rastrineobola argentea) is a freshwater tiny cyprinid endemic to Lake Victoria, Lake Kyoga and the Victoria Nile River. It is the third most important commercial fishery of Uganda after Lates niloticus and Oreochromis niloticus. The study investigated the fatty acid content of the fishmeal of whole fish of R. argentea and for differences in the fatty acid profile of the samples from the different water bodies. Fatty acid composition of fishmeal obtained from samples collected from the two lakes and the Victoria Nile River was determined using chemometric method for five fish samples from each location and subjected to multivariate analysis. In each fish the fatty acids detected ranged from 14 to 24 carbons. Palmitic (16:00), stearic (18:00), oleic (18:1n9), arachidonic (20:4n6) and docosahexaenoic (22:6n3) were the principal fatty acids in all sampled fish. The fatty acid composition showed that R. argentea contain essential unsaturated fatty acids, Eicosapentanoic acid (EPA) and Docosahexaenoic acid (DHA). A 2-way ANOVA showed that there were no significant differences at 95% level between the three samples from the three connected water bodies, therefore fatty acid profiles are probably not suitable for use as a chemotaxonomic tool for differentiating mukene stocks. This probably due to lack of physical barriers between the three connected water bodies, that allows for unlimited genetic exchange among the populations of R. argentea in the three water bodies.

Keywords: Mukene, fatty acids profiles, Nile basin waters, chemotaxonomy