GENETIC VARIATION AMONG TILAPIA SPECIES (Tilapia zilli, Oreochromis niloticus and Hemichromis fasciatus) POPULATIONS USING SIMPLE SEQUENCE REPEATS (SSR) MARKERS

Abstract

Tilapia belonging to the family Cichlidae is one of the most important cultured fish species all over the world due to their rapid growth, resistance to disease, high reproductive rate, and easy to culture in a variety of aquaculture systems. This study investigated morphological and genetic divergence of three (3) cichlids species (Tilapia zilli, Oreochromis niloticus, and Hemichromis fasciatus) collected from four (4) water bodies (Oyun dam, Moro river, Apodu dam, and Asa dam). A total of 70 specimens were collected from the various rivers. Morphometric data were then obtained from the fish. The morphometric data ranges from the body-related characters such as Body length (10.98-22.72); Body weight (15.95-32.21), Body width (6.15-9.38) to the head-related parameters like the Head length (3.48-5.91), Snout length (1.30-1.73), and Width of the head (3.59-6.05). Molecular analysis based on Simple Sequence Repeat (SSR) analysis was used to analyze variations within and among the Tilapia species. Genomic DNA from the crushed fish fin was extracted using the phenol-chloroform method. Five (5) oligonucleotide primers were screened, and four (4) primers were selected (OPA 01, OPB 02, OPC 03, and OPD 04) to amplify DNA from forty (40) samples of Tilapia species, and PCR was carried out. The Agarose gel electrophoresis results show SSR banding patterns with fragment sizes ranging from 100-1300bp and polymorphic DNA ranging from 84.61% (OPA-01 and OPC-03) to 100% (OPB-02 and OPD-04) confirming the presence of DNA. SSR is an efficient molecular marker for investigating genetic diversity in fish.