Boundaries of Morphological and Molecular Variation and the Distribution of a Miniaturized Froglet, Brachycephalus nodoterga (Anura: Brachycephalidae)

Most miniaturized froglets of the genus Brachycephalus occur in isolation in slopes of mountain ranges at elevations varying from 600 to 1,800 m in the Atlantic Forest of eastern Brazil. For organisms such as Bracycephalus with spatially discontinuous distributions, a fundamental task is to determine whether observed patterns of variation are consistent with geographic differentiation among allopatric populations within a single species or are suggestive of a potential species boundary. We address this problem by focusing on continental and island population samples potentially assignable to Brachycephalus nodoterga (Anura: Brachycephalidae) from the perspective of variation in qualitative and quantitative morphological traits and DNA sequences. Population samples from continental and island populations share color characteristics, qualitative traits, and multivariate patterns of variation and covariation in cranial metric traits. Comparative analysis of DNA sequences showed the magnitude of molecular distances between B. nodoterga and Brachycephalus ephippium to be 1 order of magnitude larger than molecular distances within B. nodoterga and B. ephippium. We interpret the combined morphological and molecular evidence to indicate that continental and island population samples examined here are conspecific. Therefore, by defining species boundaries for B. nodoterga, we also established minimal estimates of its distribution.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao PauloFundo de Apoio ao Ensino, a Pesquisa e a Extensao/Universidade Estadual de Campinas (UNICAMP)CNPqConsejo Nacional de Investigaciones Cientificas y TecnicasUniv Vila Velha, Programa Posgrad Ecol Ecossistemas, BR-29102920 Vila Velha, ES, BrazilUniv Nacl La Plata, CONICET, Fac Ciencias Nat & Museo, Div Antropol, Paseo Bosque S-N, RA-1900 La Plata, Buenos Aires, ArgentinaUniv Estadual Campinas, Programa Posgrad Genet, BR-13083970 Campinas, SP, BrazilUniv Estadual Paulista, Programa Posgrad Zool, BR-13506900 Rio Claro, SP, BrazilUniv Fed Sao Paulo, Dept Ciencias Biol, Campus Diadema,Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP, BrazilUniv Estadual Paulista, Dept Zool, BR-13506900 Rio Claro, SP, BrazilUniv Estadual Campinas, Dept Biol Anim, BR-13083970 Campinas, SP, BrazilUniv Fed Sao Paulo, Dept Ciencias Biol, Campus Diadema,Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP, BrazilFAPESP: 2005/55449-6FAPESP: 2008/50928-1FAPESP: 2008/54472-2FAPESP: 2013/50741-7FAPESP: 2011/10230-8Web of Scienc