Barcoding Antarctic Fishes: Species Discrimination and Contribution to Elucidate Ontogenetic Changes in Nototheniidae

Fish species richness in the Southern Ocean accounts for approximately 2 % of the world’s ocean species, with more than 370 species registered and several awaiting for formal description. Here we explore on the use of DNA barcoding to discriminate fishes from Antarctic Peninsula by compiling our results and placing them into a comparative framework with other previous studies to provide a comprehensive review of available barcodes for Antarctic fishes. A total of 275 specimens, belonging to 36 different putative species were barcoded. Nearly all species exhibit unique barcodes or clusters of closely related haplotypes, and only four species lacked genetic resolution using Barcode Index Numbers (BINs). Thus, ~90 % of the species barcoded in this study could be identified at species level with accuracy using BINs. However the use of nucleotic diagnostic character allowed us to discriminate the remaining species. Compiling our results with previous studies, about 80 species inhabiting the Antarctic Peninsula were already barcoded, representing approximately 60 % of the species occurring in the area. Finally, we highlighted ontogenetic morphological traits observed in some Notothenidae, which may lead to misidentification of juveniles. DNA Barcoding was a cornerstone element for obtaining a reliable identification of these specimens. These results are crucial for management and conservation purposes since an accurate species-level resolution of juveniles is necessary to determine nursery areas and to clarify species distributions.