International Journal of Fishery Science and Aquaculture ISSN 9521-4569 Vol. 5 (1), pp. 098-104, January, 2018. © Advanced Scholars Journals

Full Length Research Paper

Genetic and morphological comparism of stocks from different rivers in Malawi

*Tamika O. chihana, Bingu Bakili and Mapanje Banda

Aquaculture and Fisheries Science Department, Lilongwe University of Agriculture and Natural Resources (LUANAR), Bunda Campus, P. O. Box 219, Lilongwe, Malawi.

*Corresponding Author. Email: [email protected]

Accepted 04 January, 2018

Abstract

Fisheries management continues to be a nightmare due to over exploitation of fish stocks and various anthropogenic activities resulting in a reduction of genetic resources. Opsaridium microlepis, a commercially exploited fish species from Lake Malawi, is no exception, hence it is listed as endangered. Opsaridium microlepis stocks from four different rivers were analyzed using 13 geometric morphometric landmarks and 20 microsatellite loci, to determine if the stocks were morphologically and/or genetically different. AMOVA performed on DNA data revealed a significant (P < 0.001) genetic differentiation with 16.4% of the total genetic variance ascribed to differences among populations, and 83.6% due to differences within population. This finding was supported by higher pairwise FST values (FST = 0.17). MANOVA of morphological data showed significant body shape variation among the stocks (Wilk’s λ = 0.0913; P < 0.0001). Pairwise comparisons using both methods indicated that all pairs were significantly different, except morphologically for Bua and Linthipe (P=0.3311). The morphological differences consisted of shorter gape and shorter head of the Bua/Linthipe stock was seen in the North Rukuru and Dwangwa stocks. The morpho-genetic differentiation revealed in this study implies that the populations are distinct and should be considered as separate management and conservation units.

Key words: Lake Malawi, Mpasa, procrustes distance, genetic differentiation, endangered species, fish stocks, conservation.