Mind the gap! Integrating taxonomic approaches to assess ant diversity at the southern extreme of the Atlantic Forest

HANISCH PRISCILA E.; LAVINIA OBLANCA PABLO DAMIÁN; SUAREZ ANDREW V.; LIJTMAER DARÍO A.; LEPONCE MAURICE; PARIS CAROLINA I.; TUBARO PABLO LUIS

Ecology and Evolution

Wiley

Año: 2017 vol. 7 p. 10451 - 10466

Understanding patterns of species diversity relies on accurate taxonomywhich can only be achieved by long-term natural history research and theuse of complementary information to establish species boundaries amongcryptic taxa. We used DNA barcoding to characterize the ant diversity ofIguazú National Park (INP), a protected area of the Upper Paraná AtlanticForest ecoregion, located at the southernmost extent of this forest. Weassessed ant diversity using both cytochrome c oxidase subunit 1 (COI)sequences and traditional morphological approaches, and then comparedthe results of these two methods. We successfully obtained COI sequencesfor 312 specimens belonging to 124 species, providing a DNA barcodereference library for nearly 50% of the currently known ant fauna of INP.Our results evidenced a clear barcode gap for all but two species, with amean intraspecific divergence of 0.72%, and an average congenericdistance of 17.25%. Congruently, the library assembled here wasremarkably useful for the discrimination of the ants of INP and evenallowed us to link unidentified males and queens to their worker castes. To detect overlooked diversity, we classified the DNA barcodes into MolecularOperational Taxonomic Units (MOTUs) using three different clusteringalgorithms, and then compared their number and composition to that ofreference species identified based on morphology. The MOTU count wasalways higher than that of reference species regardless of the method,suggesting that the diversity of ants at INP could be between 6% and 10%higher than currently recognized. Lastly, our survey contributed with 78new barcode clusters to the global DNA barcode reference library, andadded 36 new records of ant species for the INP, being 23 of them newcitations for Argentina.