Application of Computational Methods in Fish Species Identification Based on Mitochondrial DNA Sequences

The great discrepancy in sequence divergence of congeneric (0.4-0.6%) and conspecific (3%) individuals makes it difficult to identify species using DNA. A 650 base pair fragment of the cytochrome c oxidase subunit I (COI) gene from the fish Pethia conchonius was analysed using 30 samples. All the samples were identified as P. conchonius and two other congeneric species showing <2% sequence divergence with 29 samples out of 30 used, of P. conchonius. Two of the P. conchonius samples clustered with Puntius terio. Using different computational methods, we identified the sequence that was tagged as Puntius chola in the NCBI database as the P. conchonius sequence.