DNA barcoding and misidentification of some marine fish species in Nigerian industrial trawl fishery

Abstract

Identification of marine fishes across their geographical distribution is based primarily on morphological features. The ability of marine fishes to adapt to environmental changes sometimes leads to morphological differences that might give rise to wrong or misidentification of the fishes, unlike genetically based identification. Fish samples were collected with a trawl net used by demersal trawlers in Nigerian coastal waters between N 4.19823⁰ E 8.29929⁰ and N 6.18855⁰ E 3.14797⁰. The average length of the COI nucleotide sequences was approximately 584 bp. A total of 30 CO1 sequences were obtained from 18 fish species within 12 families with 97–100% identity with comparison to the Genbank database and BOLD. The average divergence within a species is 4.47%, 6.10% within a genus, and 15.94% within a family, while the maximum within a species and genus is 17.54% and 19.20% within a family. Four (4) species in the Nigerian marine environment have not been sequenced before in this study: Caranx fischeri, Pseudotolithus senegallus, Lagocephalus guentheri, and Sphyraena ensis. These findings will contribute to the barcode database of global marine fish species identification, provide baseline data for marine fishes in Nigerian waters based on the CO1 region, and serve educational purposes in universities, research institutes, fishery managers, and fish stock assessment.