Open AccessMapping the hidden diversity of the Geophagus sensu stricto species group (Cichlidae: Geophagini) from the Amazon basin
Author(s) -
Aline Mourão Ximenes,
Pedro Bittencourt,
Valéria Nogueira Machado,
Tomas Hrbek,
Izeni Pires Farias
Publication year - 2021
Publication title -
peerj
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.927
H-Index - 70
ISSN - 2167-8359
DOI - 10.7717/peerj.12443
Subject(s) - biology , dna barcoding , threatened species , sensu stricto , biodiversity , amazon rainforest , lineage (genetic) , sensu , mitochondrial dna , ecology , zoology , evolutionary biology , habitat , genus , genetics , gene
South American freshwater ichthyofauna is taxonomically the most diverse on the planet, yet its diversity is still vastly underestimated. The Amazon basin alone holds more than half of this diversity. The evidence of this underestimation comes from the backlog of morphologically distinct, yet undescribed forms deposited in museum collections, and from DNA-based inventories which consistently identify large numbers of divergent lineages within even well-studied species groups. In the present study, we investigated lineage diversity within the Geophagus sensu stricto species group. To achieve these objectives, we analyzed 337 individuals sampled from 77 locations within and outside the Amazon basin representing 10 nominal and six morphologically distinct but undescribed species. We sequenced the mitochondrial cytochrome c oxidase subunit I (COI) and delimited lineages using four different single-locus species discovery methods (mPTP-15 lineages; LocMin-14 lineages; bGMYC-18 lineages; and GMYC-30 lineages). The six morphologically distinct but undescribed species were also delimited by the majority of the species discovery methods. Five of these lineages are restricted to a single collection site or a watershed and their habitats are threatened by human activities such as deforestation, agricultural activities and construction of hydroelectric plants. Our results also highlight the importance of combining DNA and morphological data in biodiversity assessment studies especially in taxonomically diverse tropical biotas.