PHENOTYPIC AND GENOTYPIC CHARACTERISATION OF WILD AND CULTURE CICHLID POPULATIONS (Tilapia guineensis) IN LAGOS STATE, NIGERIA.

This study was carried out using phenotypic and genotypic approach in characterization and identification of  Tilapia guineensis from the wild and culture. A total of forty (40) samples of T. guineensis  were collected; twenty(10) samples each of farm-raised (Akinsateru and Nigeria Institute of Oceanography & Marine Research (NIOMR) and wild (Lagos and Badagry Lagoon) were collected in Lagos State for 3 months.

There were no significant differences (P ≥ 0.05) in all the phenotypic characters measured except at the Pre-Pectoral Length (PPL), Dorsal Fin (DF) and Weight (WEI) (Table 1). These could be as result of ecological factors such as temperature, pollution; management practices in the farm, etc.

The similarity coefficient at 50% and  78% shows that there is genetic variability amongst the wild and culture samples. The observed similarities in the banding pattern at 100% of the wild and cultured environment could  be partly due to escape of the cultured into the wild during flooding of some farms or that farmers are collecting broodstock from the wild. This study provides a promising solution to DNA isolation using the more economical salting-out method for extraction and base-line data required for genetic manipulation of the selected population of the fish in aquaculture.