Little Divergence Among Mitochondrial Lineages of Prochilodus (Teleostei, Characiformes)

Abstract

Evidence that migration prevents population structure among Neotropical characiform fishes has been reported recently but the effects upon species diversification remain unclear. Migratory species of Prochilodus have complex species boundaries and intrincate taxonomy representing a good model to address such questions. Here, we analyzed 147 specimens through barcode sequences covering all species of Prochilodus across a broad geographic area of South America. Species delimitation and population genetic methods revealed very little genetic divergence among mitochondrial lineages suggesting that extensive gene flow resulted likely from the highly migratory behavior, natural hybridization or recent radiation prevent accumulation of genetic disparity among lineages. Our results clearly delimit eight genetic lineages in which four of them contain a single species and four contain more than one morphologically problematic taxon including a trans-Andean species pair and species of the P. nigricans group. Information about biogeographic distribution of haplotypes presented here might contribute to further research on the population genetics and taxonomy of Prochilodus.

Hidden diversity in Prochilodus nigricans: A new genetic lineage within the Tapajós River basin

“…The maximum likelihood results of the GMYC model performed with COI was significantly higher (L = 696.0997) than that of the null model (L0 = 642.3439), allowing us to reject the hypothesis that all individuals belong to the same molecular unit. The GMYC single threshold analysis revealed the occurrence of three MOTUs within the Amazon River basin (Fig 2), increasing the number of MOTUs reported in previous studies [15,16] in this large basin. Our study recovered the previous Western and Eastern Amazon MOTUs (showed, respectively, in blue and green clusters in Fig 2) and raised an additional one, named hereafter Tapajós MOTU (orange cluster in Fig 2).…”

“…Ten samples were obtained from the Xingu (1) and Tocantins-Araguaia (9) drainages (Fig 1, Table 1). Additionally, we retrieved 48 sequences of P. nigricans and some congeneric nominal species from previous studies [15,16,[30][31][32], available at Genbank and Barcode of Life Data Base (BOLD Systems, https://www.boldsystems.org/index.php/databases) public databases (S1 Table). https://doi.org/10.1371/journal.pone.0237916.g001…”

“…Recently, studies on molecular phylogeny have questioned the monophyly of P. nigricans pointing out the existence of two mitochondrial lineages in the Amazon River basin [15,16]. A lineage includes specimens of P. nigricans from lowlands of Western Amazon and its mainstream, while a second one is considered a complex of species that includes what is described as P. nigricans from uplands of the Eastern Amazon (Araguaia River, Upper and Middle Tapajós River), P. britskii from Apiacás (Upper Tapajós River), P. brevis from northeastern Brazil (Ceará and Rio Grande do Norte states), P. lacustris from Parnaíba River, and P. rubrotaeniatus from the Upper Orinoco and Upper Essequibo River basins [15,16]. Namely, within this complex lineage two taxonomic units, P. britskii and the P. nigricans Eastern Amazon group, were also found in the Tapajós River basin.…”

“…In this scenario, the occurrence of new taxonomic units into the Tapajós River basin can be expected. Considering the Brazilian Shield is an underestimated region of high ichthyofaunal diversity and endemism [18], and the previously reported Prochilodus phylogeny [15,16] included few individuals from Tapajós River, this basin still requires a more extensive sampling.…”

Space-time dynamics in monitoring neotropical fish communities using eDNA metabarcoding

“…in the Jequitinhonha, 370 without any success, and this species was only documented in 2009 by an environmental report 371 based on traditional sampling and morphological identification (Kullander & Lucena, 2006;372 Intertechne, 2009). An issue reported worldwide, is that even when monitoring programmes 373 are conducted, most of the data obtained are often not published or made available and thus 374 remain inaccessible to further scientific studies ( and is believed to have recently diverged from the endemic species P. hartii (Melo et al, 2018). 397…”