RESUMO
The species Anolis incredulus was proposed based on a single, poorly preserved specimen from the Sierra Maestra (mountain range) of southeastern Cuba. As its name suggests, this species was considered likely to raise doubts when it was first proposed, and it has been explicitly treated by some recent authors as a species inquirenda (a species of doubtful identity). Here we report on a second specimen of Anolis incredulus discovered in the amphibian and reptile collection of the National Museum of Natural History (Smithsonian Institution) that was collected more than 100 years before the holotype. We describe this specimen in detail and compare it both with the description of the holotype of A. incredulus and with presumed closely related Cuban species, providing evidence that it matches closely with the former and is distinct from the latter, thus corroborating the status of A. incredulus as a valid species. We also score and measure the specimen for sets of morphological characters to make inferences about its phylogenetic relationships and ecology (structural habitat use). Our results indicate that Anolis incredulus is likely a member of a clade of mostly Cuban twig-anole species and that it is a member of the twig ecomorph category, although its reported green coloration suggests either an erroneous ecomorph assignment or a difference in color from that of most other species of Cuban twig anoles.
Assuntos
Lagartos , Animais , Filogenia , EcossistemaRESUMO
Swordtail fish have been studied extensively in relation to diverse aspects of biology; however, little attention has been paid to the patterns of genetic variation within and among populations of swordtails. In this study, we sequenced the mtDNA control region from 65 individuals and 10 populations of Xiphophorus cortezi to investigate the genetic variation within and among populations, including tests for correlations between genetic and geographic distances and tests for species monophyly. We found low gene and nucleotide diversity within populations and high degrees of genetic differentiation among populations. Significant and positive correlations between genetic distance and both river and straight-line geographic distance indicate that genetic differentiation among X. cortezi populations can be explained, to some extent, by an isolation-by-distance model and provide evidence of stream capture. Phylogenetic analyses suggest that X. cortezi is paraphyletic relative to X. malinche, raising questions concerning the status of these taxa as separate species.