DNA Barcoding Southwestern Atlantic Skates: A 20-Year Effort in Building a Species Identification Library

MABRAGAÑA, EZEQUIEL; GABBANELLI, VALERIA; MATUSEVICH, FLORENCIA; VAZQUEZ, DIEGO MARTÍN; DELPIANI, SERGIO MATÍAS; LENAIN, VICTORIA MALVINA; ROSSO, JUAN JOSÉ; GONZÁLEZ-CASTRO, MARIANO; HANNER, ROBERT; DÍAZ DE ASTARLOA, JUAN MARTÍN

Diversity

MDPI

Año: 2025 vol. 17 p. 1 - 26

The skate fauna in the Southwest Atlantic Ocean (SWA; 34–55◦ S) is representedby ~32 species, many of which share external features that have led to misidentificationsand deficient fishery statistics. The use of DNA barcoding to discriminate SWA skate specieswas explored after 20 years of surveys. COI sequences were subjected to distance-basedneighbor-joining (NJ), maximum likelihood (ML), barcode index number (BIN), automaticbarcode gap discovery (ABGD), and nucleotide diagnostic character (NDC) analyses. Forwidely distributed species, a haplotype network was built. Overall, 187 specimens and31 egg cases from 26 skate species were barcoded. NJ and ML analyses showed thatnearly all species exhibited unique barcodes or clusters of closely related haplotypes,except for Psammobatis normani/P. rudis and Dipturus trachyderma/D. argentinensis. Thefirst pair was discriminated by NCD. BIN analysis recovered 17 groups, whereas ABGDrecovered 23, better reflecting taxonomic diversity. In summary, 24 species were resolvedby COI. Phylogeographic signals were observed for Amblyraja doellojuradoi and Zearajabrevicaudata. Compiling our results with data from BOLD, almost all the species occurringin the area possess barcodes, contributing to completing and curating the BOLD referencelibrary, which constitutes an important tool for resolving taxonomic issues, tracing fisheryproducts, and performing eDNA biomonitoring.