Abstract Fiddler crabs are important components of intertidal benthic macrofauna in estuarine habitats. However, these invertebrates often inhabit areas under anthropogenic-driven changes. In this study, we evaluated the habitat quality and the population biology of the fiddler crab Uca maracoani (Latreille, 1802) in a mangrove area under anthropogenic influence, on the southern coast of São Paulo state, Brazil. Sediment samples for ecotoxicological analyses and data on the population biology of U. maracoani were collected monthly between October 2008 and October 2009. Contamination was observed in sediment samples from all months, indicating that benthic organisms inhabiting the study area are continuously exposed to toxicity. The sex ratio did not deviate from 1:1 for the whole population of U. maracoani, within any given month (except in October 2008, when males outnumbered females). Adult males and females showed a similar size, while juvenile females were larger than juvenile males, probably reflecting that females attained sexual maturity at a larger size than males. For both juvenile and adult stages, the major cheliped propodus length and height in males and the abdomen width in females showed positive allometry. The size-frequency distribution of the studied population varied from unimodal to bimodal. Juveniles were recorded in all months, suggesting the studied population has continuous recruitment. In contrast, ovigerous females were not found in the study area for several months. Although U. maracoani is continuously exposed to contamination present in the sediment, it presents a well-established population and seems to persist in the study area.

Abstract 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.

ABSTRACT 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.

Resumo Um estudo comparativo sobre o tamanho e a forma de Leptuca uruguayensis foi realizado entre as populações do Rio das Garças, Brasil (BP) e do Rio Solís Grande, Uruguai (UP). O tamanho do início da maturidade sexual, também foi estimado para UP. Foi analisado um total de 36 indivíduos para BP e 387 para UP. Para a análise do crescimento relativo, a largura da carapaça (LC) para ambos os sexos, comprimento do maior quelípodo (CMQ) dos machos e a largura do abdome (LA) das fêmeas foram mensurados. O tamanho da carapaça e do quelípodo foi maior em UP. A forma também diferiu, sendo a carapaça de UP mais ampla do que BP; rostro projetado para a frente e margem posterior posicionada mais anteriormente; o quelípodo de UP também foi mais amplo do que BP. Em UP, a LC variou de 4,28-19,5 mm (machos) e 2,53-16,3 mm (fêmeas); o CMQ variou de 1,79-31,60 mm (machos) e a LA de 0,80-8,53 mm (fêmeas). O início da maturidade sexual para UP foi estimado em 12,20 mm LC (machos) e 7,81 mm (fêmeas). Essas diferenças podem indicar que variáveis abióticas estão atuando distintamente nas duas localidades.

Abstract A comparative study on size and shape of Leptuca uruguayensis was carried out between populations from Garças River, Brazil (BP), and Solís Grande River, Uruguay (UP). The size of the onset of sexual maturity was also estimated for UP. A total of 36 crabs BP and 387 crabs UP were analyzed. In the relative growth analysis, carapace width (CW) for both sexes, major cheliped length (LMC) for males and abdomen width (AW) for females were measured. The centroid size of carapace (1.40±0.19 cm BP and 1.88±0.30 cm UP) and cheliped (1.16±0.22 cm BP and 1.58±0.45 cm UP) differed significantly (p<0.001). The shape also differed significantly (p<0.001), having UP wider carapace than BP, rostrum projected forward and posterior margin positioned more anteriorly; the cheliped of UP was also wider than BP. In UP, males' CW ranged 4.28-19.5 mm and females' 2.53-16.3 mm CW; males' LMC ranged 1.79-31.60 mm and females' AW, 0.80-8.53 mm. The onset of sexual maturity of UP was estimated in 12.20 mm CW for males and 7.81 mm for females. These differences are likely related to abiotic variables acting distinctly in the two localities.

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.

Resumo Caranguejos braquiúros são um dos grupos mais diversificados de crustáceos, ocorrendo na maioria dos habitats costeiros. Devido à alta diversificação morfológica, procurou-se verificar a existência de padrões morfológicos relacionados ao habitat desses animais. Foram analisadas 17 espécies provenientes de manguezal, costão rochoso, praia de areia e ecossistema exclusivamente aquático marinho/estuarino. Em cada ambiente um total de 16 medidas lineares foi obtido para machos e 17 de fêmeas. Foram discriminados três grupos funcionais de espécies de caranguejos, baseado em seu habitat: 1. Substratos complexos, 2. Semiterrestre, 3. Exclusivamente aquático. As espécies pertencentes ao grupo Substratos complexos apresentaram pernas ambulatórias longas, bem como heteroquelia relacionada à vida em substratos irregulares. Espécies do grupo Semiterrestre apresentaram pernas ambulatórias de tamanhos distintos, o que lhes permite caminhar de maneira ágil sobre o ambiente terrestre graças à quarta perna ambulatória maior e aos pedúnculos oculares longos, importantes para a comunicação visual. Espécies do grupo Exclusivamente aquático apresentaram as maiores larguras de carapaça e pedúnculos oculares curtos. A presença de distintas linhagens de caranguejos nos ambientes analisados permitiu demonstrar uma clara convergência evolutiva, adaptando os caranguejos ao seu habitat e ambiente específico.

Abstract Brachyuran crabs are one of the most diverse taxa of crustaceans, occurring in almost all coastal habitats. Due to their high morphological diversification, the authors sought to ascertain the existence of morphological patterns related to the habitat of coastal brachyuran crabs. We analyzed 17 species from mangrove forests, rocky shores, sandy beaches and exclusively aquatic marine/estuarine ecosystems. A total of 16 linear measurements of males and 17 of females were obtained for each habitat. We were able to discriminate three functional groups of crab species, based on their habitat: 1. Complex Substrates, 2. Semiterrestrial, 3. Exclusively Aquatic. The species belonging to the Complex Substrates group had long ambulatory legs, as well as being heteroquely related to uneven terrain. Semiterrestrial species showed ambulatory legs of different sizes, allowing them to walk easily on the terrestrial terrain due to the long fourth ambulatory leg, and long eyestalks which are important for visual communication. Exclusively Aquatic species showed the largest carapace widths and the shortest eyestalks. The presence of different crab lineages in the environments analyzed allows us to demonstrate the clear evolutionary convergence, by which the crabs adapted to their specific habitat and environment.

RESUMO Um estudo sobre o dimorfismo sexual no caranguejo Hepatus pudibundus (Herbst, 1785) foi realizado utilizando morfometria geométrica. A carapaça de 28 machos e 30 fêmeas e o própodo dos quelípodos direito e esquerdo de 22 machos e 26 fêmeas foram analisados. Foram estabelecidos 13 marcos anatômicos bidimensionais na carapaça e 10 no própodo para ambos os sexos. Uma Análise Generalizada de Procrustes baseada na configuração dos marcos anatômicos foi utilizada para separar os componentes de tamanho e de forma. Um Teste-t de Student foi utilizada para determinar a significância estatística do dimorfismo sexual da carapaça e do própodo dos quelípodos. A variação na forma das estruturas foi avaliada através de uma Análise de Função Discriminante. Houve dimorfismo sexual na forma e no tamanho das estruturas analisadas. Machos mostraram dimensões menores do que fêmeas. A carapaça das fêmeas foi mais larga na região posterior do que em machos, indicando uma ampliação da área para acomodação da massa de ovos. O dedo fixo do própodo dos quelípodos das fêmeas está mais voltado para a parte posterior e pode facilitar a limpeza dos ovos fixados na câmara abdominal. Nossos resultados trazem novas informações sobre o desenvolvimento de caracteres sexuais secundários e as suas consequências sobre a forma da carapaça e o própodo dos quelípodos em machos e fêmeas de H. pudibundus.

ABSTRACT A study on sexual dimorphism in Hepatus pudibundus (Herbst, 1785) was performed using geometric morphometrics. The carapace of 28 males and 30 females and the left and right cheliped propodus of 22 males and 26 females were analyzed. Thirteen landmarks were established in the carapace and 10 in the cheliped propodus. A Generalized Procrustes Analysis based on landmark configurations was used to separate the components of size and shape. A Student t-test was used to determine the statistically significant sexual dimorphism of the carapace and the cheliped propodus. The variation in the shape of the structures was evaluated with a discriminant analysis. There was sexual dimorphism in the analyzed structures. Males were smaller than females. The carapace of females was larger in the posterior region than in males, indicating an expansion of the area for accommodation of the egg mass. The fixed finger of the cheliped propodus of females is more posteriorly arched that can be used to facilitate the cleaning of eggs laid in the abdominal chamber. Our results provide new information about the development of sexual secondary characters and their effects on the shape of the carapace and the cheliped propodus in males and females of H. pudibundus.

RESUMO O primeiro estágio juvenil do caranguejo chama-maré Minuca mordax foi descrito. Larvas zoea foram obtidas de fêmeas ovígeras e cultivadas em laboratório até atingir o primeiro estágio juvenil. O desenvolvimento de zoea I até o primeiro estágio juvenil teve duração de 35 dias após a eclosão. O cultivo foi mantido em um aquário com salinidade 20‰, sob fotoperíodo (claro: escuro/12:12) e temperatura (25°C) constante. Os juvenis foram dissecados e os apêndices desenhados e descritos. O primeiro estágio juvenil de M. mordax pode ser morfologicamente distinto do mesmo estágio de M. burgersi and L. cumulanta por apresentar antênula com endopodito bisegmentado (3-segmentos em M. burgersi, não segmentado em L. cumulanta), maxílula com endopodito não segmentado (2-segmentos em M. burgersi e L. cumulanta), e primeiro e segundo maxilípodo com endopodito 4-segmentado (respectivamente não segmentado e 5-segmentos em M. burgersi e L. cumulanta). Os seguintes caracteres são comuns a estas três espécies: pedúnculo da antênula bissegmentado; antênula com endopodito não segmentado; presença de estetascos na antênula; pedúnculo da antena trisegmentado; flagelo da antena 6-segmentado; mandíbula trisegmentada; maxila com coxal e basal endito bilobado; primeira, segunda e terceira maxila com exopodito bissegmentado e abdômen com seis somitos que são mais largos do que longos.

ABSTRACT The first stage of the fiddler crab Minuca mordax is described here. Zoea larvae obtained from four ovigerous female were reared in the laboratory until the development of the first crab stage. The development from zoea I to the first juvenile instar lasted 35 days after hatching. The first crab stage of Minuca mordax can be morphologically distinguished from those of Minuca burgersi and Leptuca cumulanta by a 2-segmented antennule endopod (3-segmented in M. burgersi, unsegmented in L. cumulanta), an unsegmented maxillule endopod (2-segmented in M. burgersi and L. cumulanta), and a 4-segmented first and second maxilliped endopod (respectively unsegmented and 5-segmented in M. burgersi and L. cumulanta). The three species have the following characters in common: segmented peduncle of antennule 2; endopod of antennule unsegmented; presence of aesthetascs on the antennule; peduncle of antenna 3-segmented; flagellum of antenna 6-segmented; mandible 3-segmented; maxilla with coxal and basal endite bilobed; first, second and third maxillae with exopod 2-segmented and abdomen with six somites that are wider than long.

This work aims to estimate the average size at the onset of morphological and physiological sexual maturity and the reproductive period of Callinectes danae. Specimens were captured from a shrimp fishing boat equipped with a trawl net from March 2009 to February 2010. After sorting, crabs were sexed, and the following morphometric dimensions were measured: carapace width (CW), length and height of the major (MAP and HMAP), and the minor cheliped propodus (MIP and HMIP) for both sexes, and the abdominal width for females (AW). The onset of morphological maturity was estimated with the REGRANS program, in which the inflection point is calculated. The size at the onset of physiological maturity was determined by logistic regressions fitted to the relationships between the percentages of juvenile and adult individuals of each CW. A total of 893 individuals were sampled. Of these individuals, 389 were males, 472 non-ovigerous females, and 32 ovigerous females. The CW ranged from 19.81 to 117.17 mm for males, 19.91 to 113.11 mm for non-ovigerous females, and 70.55 to 88.60 mm for ovigerous females. Morphological sexual maturity was attained at 86.47 mm CW (males) and 67.87 mm CW (females). The size at the onset of physiological maturity was calculated to be 86.50 mm CW (males) and 67.00 mm CW (females). Due to the closeness of these values, both techniques were deemed suitable for determination of the onset of sexual maturity in C. danae. This species reproduces throughout the year, but reproduction is more intense during the winter. Mature males are present throughout the year. Data from this investigation will help resource managers to develop strategies that will ensure a sustainable harvest of this important species of swimming crab in southern Brazil.

A study on sexual dimorphism in Aegla marginata was conducted using geometric morphometric methods. The carapace of 47 females and 75 males and the left and right cheliped propodus of 29 females and 40 males were analyzed. Eighteen landmarks were established in the carapace and 10 in the cheliped propodus. A Generalized Procrustes Analysis based on landmark configurations was used to separate the components of size and shape. A Student t-test was used to determine whether statistically significant sexual dimorphism was shown by the carapace and the cheliped propodus. The variation in the shape of the structures was evaluated with a discriminant analysis. Our results show that there is no sexual dimorphism in the carapace of A. marginata. However, the size of the propodus differed statistically between the sexes. The carapace shape differed between the sexes: the females showed a wider posterior area and a narrower anterior area than the males. The shape of the cheliped propodus also differed between the sexes: overall, the females had a longer and narrower cheliped propodus than the males. The variations in the carapace shape found in this study confirm the results of other studies on aeglid morphology; however, the information presented by this study regarding variation in the shape of the cheliped propodus is new to the literature. The geometric morphometric approach applied in this study provided useful tools for achieving the proposed objectives.

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.