Molecular characterisation of two cichlids populations (Tilapia guineensis and Sarotherodon melanotheron) from different water bodies in Lagos State, Nigeria

This study used random amplified polymerase DNA technique (RAPD) to characterize two populations of cichlids species Tilapia guineensis and Sarotherodon melanotheron from selected two water bodies in Lagos using molecular approach. Ten samples of each S. melanotheron and T. guineensis with standard length value ranging between 8.4 and 17.2 cm and their weight ranging between 26.1 to 133 g were collected from Lagos Lagoon, Badagry, Nigerian Institute for Oceanography and Marine Research and Akinsateru fish farm, respectively. The DNA of the fish samples were extracted using salt-out method. RAPD analysis was carried out using RAPD primers (OPC 04, 05, 10, OPR 02 and OPI 05). Depending on the similarity coefficient through the used primers, the similarity between T. guineensis and S. melanotheron from the wild was 78%; between T. guineensis and S. melanotheron from the culture was 80%; and 100% of both wild and culture of samples; 82 and 88% of T. guineensis and S. melanotheron from wild and culture, respectively. The description of this similarity coefficient is not simple, especially when more than one character is involved in the same cluster. The values of the genetic distances obtained were utilized to generate a distance matrix to construct a dendrogram which linked the studied species DNA for possible variation in their genetic makeup. This generated banding pattern populations of T. guineensis and S. melanotheron from the wild and cultured environment have similar DNA profile, which indicated that there were similarities among the fish species from these environments which can lead to high probability of hybridization between the very closed species to improve the genetic characters; also, high quality and quantity of DNA can be gotten in using salt-out method for extraction and pure strain of the samples can be gotten from wild and culture.