Phylogeographic Structure within the Fiddler Crabs Leptuca thayeri and Uca maracoani (Brachyura, Ocypodidae) along the Tropical West Atlantic.

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.

Population structure and growth of two opulations of Aegla Schmitti Hobbs III, 1979 (Anomura, Aeglidae) in the eastern Paraná state, Brazil.

The population structure and growth of two populations (Arraial and Capivari rivers) of Aegla schmitti was evaluated. The following parameters were determined: size, age structure, sex ratio, recruitment period, and sampling method selectivity (traps and handnet). There was variation between males and females. The carapace length size class distribution was unimodal in the Arraial River, and polymodal in the Capivari River. The sampling method influenced the proportion of demographic categories. The recruitment occurred mostly between October and December. The growth curves for the Arraial and Capivari rivers, respectively, were Ct= 26,50[1- e -0,004(t+53,36)] and Ct= 34,79[1- e -0,0024(t+122,34)] for males, and Ct= 23,07[1- e -0.0027(t+23,18)] and Ct= 25.52[1- e -0,0033(t+19,51)] for females. The maximum CL estimated for males and females were 26.50 and 23.07mm for the Arraial River, and 34.79 and 25.52mm for the Capivari River. Longevity was estimated in 2 years for females of both populations, and 2.5 and 3 years for males of the Arraial and Capivari rivers, respectively. The results allow for the characterization of the growth patterns of A. schmitti in two hydrographic basins, providing information for the species' preservation and also demonstrating the selectivity of the different sampling methods used for aeglids.

Ontogenetic shape changes and sexual dimorphism in Aegla marginata Bond-Buckup and Buckup, 1994.

A study on relative growth, sexual dimorphism and ontogenetic trajectory was carried out in a population of the aeglidAegla marginata coming from Barrinha River, Iguape River Basin, Tunas do Paraná, Paraná State, Brazil. The size the of morphological sexual maturity was estimated for males and females. The analysis of sexual dimorphism and ontogenetic trajectory were performed using geometric morphometric technique. Males reach maturity with 10.58 mm of carapace length (CL) and females with 10.38 mm CL. Sexual size dimorphism was only visible among adults, with males reaching larger sizes. This is probably related to the reproductive strategy of males. However, sexual shape dimorphism was found for both juveniles and adults: the posterior region of the carapace was wider in females. As the contrast of this feature was stronger in adults, it can be considered that large abdomen is advantageous for egg incubation. The allometric trajectories of juveniles presented similar directions, becoming divergent during the adult phase. The shape variation inA. marginataoccurred gradually throughout its development, with no abrupt transformation upon reaching sexual maturity. The reproductive adaptation is the main reason for the morphological variation within populations ofA. marginata.

Genetic and Morphological Differentiation of the Semiterrestrial Crab Armases angustipes (Brachyura: Sesarmidae) along the Brazilian Coast.

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.

Asynchronous Hatching and Extended Parental Care in Aegla schmitti (Decapoda, Anomura)

ABSTRACT The aim of this study was to describe the behavior of newly-hatched juveniles and maternal care in Aegla schmitti. The experiment was conducted using seven ovigerous females with eggs at different stages of embryonic development and 12 eggs that had been placed in a separate aquarium. We observed asynchronous hatching in all females, with a mean of 66 hatched juveniles per female. The females also exhibited extended maternal care, allowing the juveniles to remain inside their abdominal chamber or on other parts of their body in the first few days after hatching. The juveniles that hatched in a separate aquarium fed on the remaining eggs, despite food being available. The incubation period and number of hatched eggs are highly variable between species with direct development, with no clear pattern being evident. However, asynchrony in hatching time is apparently common among freshwater anomurans, most likely due to the environmental conditions in which they live. Parental care is an important trait for crustaceans that live in osmotically unfavorable environments, such as freshwater, increasing the survival rate of juveniles.

Os caranguejos Eriphiidae, Menippidae, Panopeidae e Pilumnidae (Crustacea Brachyura) de águas rasas do litoral do Paraná, com chave pictórica de identificação para as espécies / The Eriphiidae, Menippidae, Panopeidae and Pilumnidae crabs (Crustacea Brachyura) from shallow waters of the Paraná State coast, Brazil, with pictorial identification key for species

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.