Use of DNA barcoding in the assignment of commercially valuable fish species from Romania

DNA barcoding is a molecular technique frequently used either for biodiversity monitoring and fish conservation or in the identification of the species of origin for raw and processed food from restaurants or fish markets. The most important aspect of this technique is that it works for all stages of life and can be used to distinguish between closely related taxa. Also, the technique has been used to unmask attempts of frauds in fish markets where more desirable and expensive fish are sometimes substituted with lower valued species. Our study aims to test the utility of the COI barcoding gene in the correct identification of several economically and ecologically valuable fish species, and interspecies hybrids, from Romanian wild fauna, aquaculture and fish markets. By combining the 122 COI sequences generated here with additional barcodes downloaded from GenBank and BOLD we screened several members of Acipenseriformes and Salmoniformes. While COI was able to correctly classify the majority of Salmoniformes, the identification process for Acipenseriformes proved more difficult, especially in the case of hybrids. Although the results show that DNA barcodes present a low degree of interspecies variation making classification possible only at the genus level, this technique is still relatively cheap, fast, and useful in the identification of incorrectly labelled market products.