More than 50% of fish farming in Zambia grow the exotic Oreochromis niloticus, However, O. niloticus is a threat to the conservational status of the local strains, whose effects range from hybridization, competition, and predation. To protect local species and for the sustainability of the industry, an indigenous species needs to be promoted for culture in Zambia, presently many authors have suggested O. andersonii as the most adequate alternative for culture in Zambia. in order to produce adequate fingerlings needed by the growing aquaculture industry in Zambia, there is need to learn the reproductive biology of the species and its various strains.
Three different Populations were used in the present study including the National Aquaculture Research and Development Centre (NARDC), which had been at the station for more than 10 years. The Supper Upper Zambezi and Luangwa populations all collected from their respective river systems in the wild. The fish were then conditioned for 6 months, being exposed to same management regime and water environment, after which they were paired in breeding hapas (2m x 1m) in a ratio of 1:1 for spawning.
The result of the present study showed that the NARDC population gonadal somatic index (GSI) and Gonadal metric ratio (GMR) were significantly higher (P<0.05) compared to the wild Luangwa and Supper Upper Zambezi populations. However, no significant differences were detected in other parameters such as fecundity and hatchability across the three populations. The percentage of spawning females per population varied, the Wild Luangwa population had more females that spawned followed by NARDC and Supper Upper Zambezi.
The study reviewed that, there are very little variations across the three populations examined in the study, we also conclude that despite the wide hydro-geographical origin of the three populations, they have not diverged significantly from one another to reach an extent were the differences that might be present in genotype to be actively expressed in the phenotypes considered in this study. This indicates that no population could be superior to the other and as such all populations of O. andersonii will perform similar under same environment and management