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

Abstract

This study is focused on a poorly known genus of small killifishes, Xenurolebias, comprising species uniquely living in temporary pools of the Atlantic Forest in the coastal plains of eastern Brazil (a region undergoing intense deforestation). Xenurolebias 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: X. myersi (Carvalho) from the Itaúnas river basin and adjacent smaller drainages; X. izecksohni (Cruz) from the Barra Seca river basin; X. cricarensis Costa, sp. nov., from the São Mateus river basin; and X. pataxo Costa, sp. nov., from the Mucuri, Itanhem and Jucuruçu river basins. Recognition of four distinct species in Xenurolebias should change views about the conservation of the species, one of which (X. pataxo) is seriously endangered and should be considered a priority for conservation.http://zoobank.org/urn:lsid:zoobank.org:pub:8485DD00-3F30-4C9F-9682-62C4718D53D9

Keywords:

• annualism
• biodiversity
• killifishes
• molecular systematics
• species delimitation
• tropical rainforest

Acknowledgements

Special thanks are due to C.P. Bove and B.B. Costa for accompanying the first author on several expeditions to collect killifishes. We are grateful to M.A. Barbosa, P.H.N. Bragança, J.L. Mattos, C. Mello, G.J. Silva and O.C. Simões, for help during collecting trips; to M. Britto, P. Buckup, E. Henschel and O. Oyakawa for curatorial support; to A.C. S. Araujo for hospitality and support in Reserva Natural Vale; and to the Willi Hennig Society for making available TNT. The manuscript benefited from the valuable criticisms and suggestions provided by K.W. Conway and two anonymous reviewers. This study was funded by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico – Ministério de Ciência e Tecnologia), FAPERJ (Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro) and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) [grant numbers 303353/2010-4, 562141/2010-3 and 103.189/2011]. Collections were made with permits and licence provided by IBAMA (Instituto Brasileiro de Meio Ambiente e dos Recursos Naturais Renováveis), ICMBio (Instituto Chico Mendes de Conservação da Biodiversidade) and IEMA/ES (Instituto Estadual de Meio Ambiente do Espírito Santo).

Associate Editor: Kevin Conway