Zambia is the sixth largest aquaculture producer in Africa. However, the aquaculture sector in Zambia still faces challenges which include, among others, inadequate supply of quality seed, inappropriate farming technologies and high cost of feed. The industry is dominated by tilapia species, with the majority of fish farmers still using inferior stocks, particularly the local species. To address the challenge of inferior stocks, the government has initiated the genetic improvement of O. andersonii, a key local species in Zambia. However, there are gaps regarding the genetic diversity of the species. A study was therefore undertaken to investigate the morphological- and genetic diversity- among four populations of O.andersonii in Zambia using two approaches; geometric morphometrics and microsatellite markers, respectively.
In the first approach, data for geometric morphometrics, was collected by taking digital images of four different populations of O. andersonii, these images were processed by TPSDIG software and analyzed using MorphoJ program. The spline deformation grids showed different forms of deformations across the populations, especially in the head region, and the deformations on the mouth were clearly visible. The space defined by the first two canonical vectors disclosed two groups of populations, one formed by the Zambezi population; and a second representing the Mwandi, Kafue and Luangwa populations.
The second approach used molecular characterization to assess the genetic variability of O. andersonii across six microsatellite loci among the four populations. The Luangwa population had the maximum degree of variation (He = 0.528) whilst the Zambezi population had the least degree of variation (He = 0.351). Sub-structuring was found and a rooted phylogram of the populations showed two major distinct branches, with the Zambezi distinct from the rest of the populations.
These preliminary results indicate variation among the populations of O. andersonii under this study, providing evidence of potential genetic improvement in the species.