Integrative taxonomy supports new candidate fish species in a poorly studied neotropical region: the Jequitinhonha River Basin

Abstract

Molecular identification through DNA barcoding has been proposed as a way to standardize a global biodiversity identification system using a partial sequence of the mitochondrial COI gene. We applied an integrative approach using DNA barcoding and traditional morphology-based bioassessment to identify fish from a neotropical region possessing low taxonomic knowledge: the Jequitinhonha River Basin (Southeastern Brazil). The Jequitinhonha River Basin (JRB) has a high rate of endemism and is considered an area of high priority for fish conservation, with estimates indicating the presence of around 110 native and non-indigenous species. DNA barcodes were obtained from 260 individuals belonging to 52 species distributed among 35 genera, 21 families and 6 orders, including threatened and rare species such as Rhamdia jequitinhonha and Steindachneridion amblyurum. The mean Kimura two-parameter genetic distances within species, genera and families were: 0.44, 12.16 and 20.58 %, respectively. Mean intraspecific genetic variation ranged from 0 to 11.43 %, and high values (>2 %) were recovered for five species. Species with a deep intraspecific distance, possibly flagging overlooked taxa, were detected within the genus Pimelodella. Fifteen species, only identified to the genus level, had unique BINs, with a nearest neighbor distance over 2 % and therefore, potential new candidate species supported by DNA barcoding. The integrative taxonomy approach using DNA barcoding and traditional taxonomy may be a remedy to taxonomy impediment, accelerating species identification by flagging potential new candidate species and to adequately conserve the megadiverse neotropical ichthyofauna.

Description of a new species of Pareiorhaphis (Loricariidae: Neoplecostominae) from the rio Jequitinhonha basin, Minas Gerais, eastern Brazil

“…In addition, no other neoplecostomine have been reported in that basin since Oliveira, Oyakawa (1999) described Pareiorhaphis stephanus from the ribeirão das Pedras, a headwater tributary to the rio Jequitinhonha basin near Diamantina, 2 e170007 [2] Minas Gerais State. Recently, however, a possible second species of Pareiorhaphis has been identified based on DNA barcode comparison and since its genetic distance from P. stephanus was higher than 2% (namely 5.79%), it was considered a candidate new species by Pugedo et al (2016), what was confirmed with the present morphometric analysis. Various ichthyological surveys conducted by the authors in tributaries to upper and middle portions of the rio Jequitinhonha basin during the last few years, have produced good series of that distinct, undescribed species of Pareiorhaphis, which is formally described in the present paper.…”

Systematic assessment of the Leporinus desmotes species complex, with a description of two new species

“…Though the sample sizes are too low to be conclusive on their own, this level of differentiation suggests the presence of at least three distinct species under a phylogenetic species concept. Similar levels of differentiation have been found among other closely related species in Leporinus (Avelino et al, 2015), as well as many other Neotropical fish groups (Gomes et al, 2015;Pugedo et al, 2016).…”

DNA barcoding fishes from the Congo and the Lower Guinean provinces: Assembling a reference library for poorly inventoried fauna

“…The goal of this campaign is to allow fish species identification through the comparison of query sequences against the reference sequence database in the Barcode of Life Data Systems, BOLD (Ratnasingham & Hebert, 2007). DNA barcode libraries also facilitate species discovery when morphology alone is insufficient (April, Mayden, Hanner, & Bernatchez, 2011) and particularly in poorly inventoried areas characterized by taxonomically hyperdiverse faunae (Pereira, Hanner, Foresti, & Oliveira, 2013;Pugedo, Andrade Neto, Pessali, Birindelli, & Carvalho, 2016).…”