RESUMEN
Most fiddler crabs have an extended planktonic larval phase, potentially maintaining gene flow among widely separated populations, in the absence of marine barriers. Such marine barriers could be long coastal stretches without suitable habitat, freshwater plumes caused by large river mouths, or strong currents. Typically, fiddler crabs inhabit mangrove habitats, and as mangroves tend to have a patchy distribution, it is important to gather information on the connectivity between neighboring mangroves and recognize local endemisms. To detect potential genetic differentiation among mangrove-dwelling populations of Leptuca thayeri and Uca maracoani along several thousand kilometers of a tropical coastline, mtDNA sequences of different populations from Brazil and two Caribbean islands were analyzed and compared. As shown in previous studies with fiddler crabs, Brazilian populations are genetically indiscernible, and our data suggest the absence of long-standing gene flow barriers in the two studied species along the Brazilian coast. This includes both sides of the postulated biogeographic barriers corresponding to the split of the Central South Equatorial Current and to the Amazon River freshwater plume. In contrast, conspecific individuals from the Greater Antilles carried different haplotypes, suggesting a biogeographical barrier between Brazil and the Caribbean, apparently having limited gene flow between both regions for extended time periods.
RESUMEN
The genetic and morphometric population structures of the semiterrestrial crab Armases angustipes from along the Brazilian coast were examined. The influence of the Central South Equatorial Current on larval dispersal of A. angustipes also was evaluated. Six populations were sampled from estuarine areas in São Luis do Maranhão, Maranhão; Natal, Rio Grande do Norte; Maceió, Alagoas; Ilhéus, Bahia; Aracruz, Espírito Santo; and Guaratuba, Paraná. Patterns of genetic differentiation were assessed using DNA sequence data corresponding to parts of the mitochondrial cytochrome c oxidase subunit 1. Geometric morphometric techniques were used to evaluate morphological variation in shape and size of the carapace and right cheliped propodus. Our results revealed low genetic variability and lack of phylogeographic structure; geometric morphometrics showed statistically significant morphological differentiation and geographic structuring. Our data indicate the absence of possible barriers to gene flow for this mobile species, and no clear correlation of morphological or genetic variation with ocean currents and/or geographic distance. Our results also suggest that historical geological and climatological events and/or possible bottleneck effects influenced the current low genetic variability among the populations of A. angustipes.
Asunto(s)
Braquiuros/anatomía & histología , Braquiuros/genética , Variación Genética , Animales , Braquiuros/clasificación , Brasil , Complejo IV de Transporte de Electrones/genética , Flujo Génico , Genética de Población , Filogeografía , Dinámica Poblacional , Especificidad de la Especie , Movimientos del AguaRESUMEN
Uma chave pictórica de identificação foi elaborada para as espécies de caranguejos das famílias Eriphiidae, Menippidae, Panopeidae e Pilumnidae ocorrentes em águas rasas do litoral do Estado do Paraná. Uma descrição das características de reconhecimento e figuras das espécies também são apresentadas. Exemplares vivos foram obtidos de manguezal, estuário e cultivo de ostras na Baía de Guaratuba e costão rochoso de Matinhos. Os desenhos e a análise foram baseados nos exemplares coletados recentemente e naqueles depositados no Museu de História Natural do Capão da Imbuia e no Laboratório de Ecologia de Crustacea UFPR. Um total de 13 espécies foi analisado, das quais nove de Panopeidae, duas de Pilumnidae e uma de Eriphiidae e Menippidae. Esta riqueza de espécies foi considerada similar à das áreas vizinhas, apesar da curta extensão do litoral do Estado do Paraná.
A pictorial species identification key for crabs of the families Eriphiidae, Menippidae, Panopeidae and Pilumnidae from shallow waters of Paraná State coast was elaborated. A description of the recognition characteristics and illustrations of the species are also presented. Crab samples were obtained from mangrove, estuary and oyster farming located in Guaratuba Bay and rocky shore in Matinhos city. Drawings and analyses were based on freshly collected specimens and on those deposited at Natural History Museum of Capão da Imbuia and at Laboratory of Ecology of Crustacea UFPR. A total of 13 species were analyzed, from which nine species of Panopeidae, two Pilumnidae and one of Eriphiidae and Menippidae. This species richness was considered similar to neighboring areas in spite of the short extension of the Paraná State coast.