IIMYC   23581
INSTITUTO DE INVESTIGACIONES MARINAS Y COSTERAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
DNA Barcoding Southwestern Atlantic skates: assessing its effectiveness for species identification and highlighting cryptic species
Autor/es:
GABBANELLI VALERIA; JURADO CARLOS DAVID; MABRAGAÑA EZEQUIEL; DELPIANI SERGIO MATÍAS; DÍAZ DE ASTARLOA, J. M.; MABRAGAÑA EZEQUIEL; VAZQUEZ DIEGO MARTÍN; DELPIANI SERGIO MATÍAS; HANNER ROBERT; DÍAZ DE ASTARLOA, J. M.; GABBANELLI VALERIA; VAZQUEZ DIEGO MARTÍN; JURADO CARLOS DAVID; HANNER ROBERT
Lugar:
Joao Pessoa
Reunión:
Conferencia; III Sharks International Conference; 2018
Resumen:
Skates are a common component of the demersal fish community along the South Americancontinental shelf and slope, and have become a concern because of the considerable andincreasing catches in recent decades due to international demand. The skate fauna in theSouthwest Atlantic (34°-55°S) is represented by ~30 species grouped in two families,Arhynchobatidae and Rajidae. Several species share external characters, especially whenjuvenile, that may lead to misidentification and therefore fishery statistics may be error-proneor deficient. In this sense, molecular approach may be a complementary useful tool forhelping in both, species identification and flagging of potential cryptic species. In this study,we explore on the use of DNA Barcoding to discriminate skate species from the SouthwestAtlantic (SWA) Ocean. We also compile our results placing them into a comparativeframework with other studies to provide a comprehensive review of available barcodes forSWA skates. A total of 208 specimens belonging to 22 different species from familiesArhynchobatidae and Rajidae were successfully barcoded in our survey. The Kimura 2-parameter genetic distances averaged 0.19% within species and 3.65% within genera. Nearlyall species exhibit unique barcodes or clusters of closely related haplotypes, showing a strongconcordance between morphological identification and COI sequences clustering. The onlyexception were samples of Psammobatis normani and P. rudis, which sequences could notbe separated each other. However, the use of nucleotic diagnostic character (NDC) allowedus to discriminate them. Character-based analysis also showed that species were clustered intwo main clades corresponding to the families Arhynchobatidae and Rajidae according tocurrent classification scheme. Compiling our results with available data on the Barcode ofLife Data System, about 27 species inhabiting SWA have barcodes, representing 90 % of thespecies occurring in the area. Some species exhibited low interspecific divergence, which isreflected in the Barcode Index Number analysis: a conservative approach that clusterssequences data into Operational Taxonomic Units called BINs. Indeed, some species wereassigned to the same BIN. However, these species do not shared haplotypes and presentedunique NDC that allow to differentiate them. Finally, the presence of two different BINs forthe same nominal species, highlights a potential cryptic skate in the SWA.