Geometric morphometrics throws light on evolution of the subterranean catfish Rhamdiopsis krugi (Teleostei: Siluriformes: Heptapteridae) in eastern Brazil

Autor(es)

Bichuette, Maria Elina ^[1] ; Rantin, Bianca ^[1] ; Hingst-Zaher, Erika ^[2] ; Trajano, Eleonora ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Lab Estudos Subterraneos, BR-13565905 Sao Carlos, SP - Brazil

^[2] Inst Butantan, Museu Biol, BR-05503900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Inst Biociencias, Dept Zool, BR-05422970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Biological Journal of the Linnean Society; v. 114, n. 1, p. 136-151, JAN 2015.
• Citações Web of Science: 5

Resumo

Rhamdiopsis krugi is a highly specialized troglobitic (exclusively subterranean) catfish from phreatic water bodies of caves located within two separated metasedimentary basins in the region of Chapada Diamantina, Bahia state, Brazil. In order to test the hypothesis of isolation with differentiation of the groups from the Una-Utinga and Irece metasedimentary basins, we compared five populations among themselves and with an epigean species of Rhamdiopsis. This was accomplished using geometric morphometrics, a powerful tool for detecting differences in body shape at population and species levels. All studied samples differed significantly from each other, the epigean sample being the most distinct and the Una Basin populations clustering together. Geological and hydrological barriers explain the differences among the subterranean populations. We discuss our results together with the autapomorphies found in R.krugi, which validate its monophyly. These results imply an old age for the R.krugi clade, more than 10 Myr; alternative hypotheses are also presented. We propose a two-step vertical colonization model of the subterranean habitat through the hyporheic zone by an epigean ancestral, with a progressive acquisition of the autapomorphies characterizing R.krugi. For conservation purposes, the two differentiated sets of populations should be considered and referred to as R.krugi Una morphotype' and R.krugi Irece morphotype'.(c) 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114, 136-151. (AU)

• Processo FAPESP: 07/56337-2 - Morfometria geometrica de bagres subterraneos, genero rhamdiopsis (siluriformes: heptapteridae) da chapada diamantina, bahia central.
• Beneficiário: Bianca Rantin
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 03/00794-5 - Fauna subterrânea aquática brasileira: biodiversidade, biologia, evolução, ecologia e conservação
• Beneficiário: Eleonora Trajano
• Modalidade de apoio: Auxílio à Pesquisa - Temático