Integrative taxonomy and conservation of seasonal killifishes, <i>Xenurolebias</i> (Teleostei: Rivulidae), and the Brazilian Atlantic Forest

<div><p>This study is focused on a poorly known genus of small killifishes, <i>Xenurolebias</i>, comprising species uniquely living in temporary pools of the Atlantic Forest in the coastal plains of eastern Brazil (a region undergoing intense deforestation). <i>Xenurolebias</i> comprises two nominal, morphologically similar species, but some variability among populations suggests it represents a species complex. In order to delineate species limits, a taxonomic revision was conducted combining two different approaches: (i) a character-based approach using morphological variation (colour patterns, fin morphology, meristic and morphometric data) and (ii) a tree-based approach using mt-DNA (tRNA-Met, tRNA-Gln and ND2). The results strongly supported four species: <i>X. myersi</i> (Carvalho) from the Itaúnas river basin and adjacent smaller drainages; <i>X. izecksohni</i> (Cruz) from the Barra Seca river basin; <i>X. cricarensis</i> Costa, sp. nov., from the São Mateus river basin; and <i>X. pataxo</i> Costa, sp. nov., from the Mucuri, Itanhem and Jucuruçu river basins. Recognition of four distinct species in <i>Xenurolebias</i> should change views about the conservation of the species, one of which (<i>X. pataxo</i>) is seriously endangered and should be considered a priority for conservation.<a href="http://zoobank.org/urn:lsid:zoobank.org:pub:8485DD00-3F30-4C9F-9682-62C4718D53D9" target="_blank">http://zoobank.org/urn:lsid:zoobank.org:pub:8485DD00-3F30-4C9F-9682-62C4718D53D9</a></p>