Molecular identification of museum preserved type specimens of fish species using DNA barcoding

Abstract

Type specimens of organisms provide the basis for the identification of species. Proper phenotypic data supported by genetic evidence is crucial for every type of specimen keeping in view its significance. Several methods of species identification both morphological and genetic are being used. DNA barcoding using a fragment of cytochrome c oxidase subunit I (COI) mitochondrial gene is gaining popularity because of its accuracy and efficiency. In this study, six type specimens of endemic fishes from Pakistan preserved at Stephenson Natural History Museum, GC University, Lahore, Pakistan were analyzed for their genetic diversity from other members of the genus. COI barcode sequences of Clupisoma naziri, Barilius vagra pakistanicus, Nemacheilus naziri, Nemacheilus griffithi hazarensis, Schizothorax skarduensis, and Naziritor zhobensis were obtained and analyzed. The obtained sequences were approximately 655bp long. The average Kimura-twoparameter( K2P) distances from other members of genera were 0.608%, 0.44%, 0.42%, 0.608%, 0.945%, and 1.364% for Clupisoma naziri, Barilius vagra pakistanicus, Nemacheilus naziri, Nemacheilus griffithi hazarensis, Schizothorax skarduensis, and Naziritor zhobensis respectively. The nodes in K2P distance-based NJ (neighbor-joining) trees were supported by high bootstrap values (100%) in all the species. We conclude that COI sequencing provides an effective way of species identification and barcode generation for fish specimens.