Molecular identification of hairtail species (Pisces: Trichiuridae) based on PCR-RFLP analysis of the mitochondrial 16S rRNA gene.

A rapid PCR-RFLP analysis was designed to identify 3 closely related species of hairtails: Trichiurus lepturus, T. japonicus, and Trichiurus sp. 2, basing on partial sequence data (600 bp) of the mitochondrial DNA encoding the 16S ribosomal RNA (16S rRNA) gene. Restriction digestion analysis of the unpurified PCR products of these 3 species, using EcoRI and VspI endonucleases, generated reproducible species-specific restriction patterns showing 2 fragments (250 bp and 350 bp) for T. lepturus in EcoRI digestion and 2 fragments (196 bp and 404 bp) for T. japonicus in VspI digestion, whereas no cleavage was observed for Trichiurus sp. 2 in both EcoRI and VspI digestions. The PCR-RFLP technique developed in this study proved to be a rapid, reliable and simple method that enables easy and accurate identification of these 3 closely related species of the genus Trichiurus.