Phenotype Differentiation Between Genetically Modified and Wild Type of Nile tilapia (Oreochromis niloticus) Based on Morphometric Characteristics and Meristic Counts

Abstract

This study aims to analyze the differentiation of phenotypes for both genetically modified alongside wild-type Nile tilapia (Oreochromis niloticus) fish cultured in fiberglass tank determined using morphometric characteristics and meristic counts and contrast the number of variations in phenotype. Genetically modified Nile tilapia was produced by natural spawning for a direct injection adult with shark-DNA. Thirty individuals were collected from each of the genetically modified Nile tilapia fish and wild-type Nile tilapia fish with a final body weight (79.318±1.855and 28.712±2.054g, respectively) and 25 morphometric characters and 6 meristic counts were obtained within each group. The morphometric analysis results for the two Nile tilapia populations revealed that Trunk Length / Standard length (Tr.L/SL), Caudal peduncle Length (CPL/SL), Length of Last Dorsal Fin ray (LoLaDFR/SL), and Length of Last Anal Fin ray (LoLaAFR/SL) were high in genetically modified fish and differed from wild-type. On the other hand, the mean indices of Caudal peduncle Width (CPW/SL), Dorsal Fin Base Length (DFBL/SL), Caudal Fin Length (CFL/SL), and Length of longest anal fin spine (LoLAFS/SL) were higher in the wild-type and varied from genetically modified fish. Additionally, results of meristic counts revealed no significant differences in all the meristic indicators for each between genetically modified and wild-type Nile tilapia. In conclusion, the phenotype analysis predicated on a large number of morphometric character indices and meristic counts can be utilized to discriminate between genetically modified and wild-type Nile tilapia.