Genetic Identification of Tuna Species via High-Resolution Melting Analysis

Tunas of the genus Thunnus include some of the most economically and ecologically important fish species in the world, because of this it is important that they can be identified in the larval and juvenile stages. However, tuna larvae are difficult to identify by morphological characteristics. Previous genetic methods of identifying tuna larvae have been unsuccessful in identifying every species of Thunnus and are expensive and time consuming. High-resolution melting analysis (HRMA) is a highly sensitive, low cost, fast genotyping method amenable to high throughput that could be used to identify tuna species. In this study we develop a genetic tuna species identification assay using HRMA of single nucleotide polymorphisms (SNPs) in the mitochondrial nitrogen dehydrogenase subunit 4 gene (ND4). Short amplicon HRMA primers generate diagnostic species specific melting curves. Northern bluefin tuna (T. thynnus), southern bluefin tuna (T. maccoyii), albacore tuna (T. alalunga), blackfin tuna (T. atlanticus), yellowfin tuna (T. albacares),and bigeye tuna (T. obesus) are easily identified using this newly developed genetic assay.