32 research outputs found

    Breeding period of the arrow crab Stenorhynchus seticornis

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    Physiological maturity and relationships of growth and reproduction in the red mangrove crab Goniopsis cruentata (Latreille) (Brachyura, Grapsidae) on the coast of São Paulo, Brazil

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    Este trabalho fornece informações sobre as relações entre a maturidade sexual e o crescimento do caranguejo Goniopsis cruentata (Latreille, 1803). Durante o período de janeiro de 1995 a dezembro de 1996 foram realizadas coletas mensais na região de Ubatuba, litoral norte do Estado de São Paulo. Os animais capturados foram reunidos em quatro grupos de interesse: macho jovem, macho adulto, fêmea jovem e fêmea adulta, em que estão incluídas as ovígeras. Para cada animal foi mensurada a largura da carapaça (LC) e anotadas a condição de muda e o estágio do desenvolvimento gonadal. A maturidade fisiológica foi observada entre 21.4 e 23.7mmLC para ambos os sexos. A população amostrada apresentou atividade de muda em todas as classes de tamanho durante todo o período estudado, o que sugere o estabelecimento de um padrão de crescimento contínuo e ausência de anecdise terminal para essa espécie. Esse fato pode estar associado com a habilidade desses animais em copular durante a intermuda, gerando uma grande quantidade de indivíduos maduros durante todo o ano, garantindo a continuidade do processo reprodutivo.This investigation provided information on the physiological sexual maturity and relationships of growth and reproduction in Goniopsis cruentata (Latreille, 1803). Collections were made monthly from January 1995 through December 1996, on the northeastern coast of São Paulo State, Brazil. The crabs were grouped into juvenile males; adult males; juvenile females, and adult females, including ovigerous ones. For each specimen the carapace width (CW) was measured, and molt condition and macroscopic developmental stage of the gonad tissue were recorded. CWs of physiologically mature crabs were between 21.4 and 23.7 mm for both sexes. This population showed molt activity in all size groups throughout the study period, which suggests continuous growth and the absence of terminal anecdysis. This may be associated with the ability of these animals to copulate during the intermolt, supplying a high proportion of mature individuals over time and ensuring continuity of reproduction year-round.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    External factors determining breeding season in the red mangrove crab Goniopsis cruentata (Latreille) (Crustacea, Brachyura, Grapsidae) on the São Paulo State northern coast, Brazil

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    Made available in DSpace on 2019-09-11T20:58:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2003This study evaluated the influence of the water and air temperatures, pluviosity and photoperiod on the breeding season of Goniopsis cruentata (Latreille, 1803), in Ubatuba littoral, southeastern Brazilian coast. Monthly collections were conducted out from January/95 to December/96 in an estuarine area from 23º29'10"-23º29'45"S to 45º09'10"-45º10'00"W. Water and air temperature variation showed the highest correlation coefficient with the frequency of ovigerous females, r² = 0.73 and 0.68, respectively. However, an analysis of the set of environmental variables, revealed the photoperiod as the factor of highest association with the ovigerous frequency (r² = 0.68). This degree of association allow us to suggest that the breeding season duration of G. cruentata might have some variations over different latitudes, and such results could be quite diverse in populations from different latitudes.[Cobo, Valter José; Fransozo, Adilson] Group of Studies on Crustacean Biology, Ecology and CultureFransozo, Adilson] Universidade Estadual Paulista, BrazilCobo, Valter José] Universidade de Taubaté, Brasi

    Ecotoxicological evaluation of water of the hydrographic Basin of the Una River using the bioindicator Ceriodaphnia dubia

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    The majority of the Una River Basin is located in Taubaté County and contributes significantly to its water supply. The main goal of this research was to evaluate the water quality of the Una River using the microcrustacean C. dubia as bioindicator for tests of chronic and acute toxicity. Bimonthly water samples were obtained from each of six localities throughout the Una Basin, from March to October, 2011. Physical-chemical water parameters such as pH, electrical conductivity, hardness, dissolved oxygen and precipitation were measured and correlated to the C. dubia reproductive rates. No significant relationships were found between the water’s electrical conductivity and precipitation with respect to bioindicator reproductive rates. However, at the Sete Voltas, Antas and Rocinha Sub-Basins, significant interactions were detected between some water parameters and reproductive rates, suggesting that water may constrain the reproduction of C. dubia. Acute toxicity was not detected in any of the six sites, while chronic toxicity was recorded at Rocinha, Sete Voltas, Antas, Médio and Baixo Una Sub-Basins. In general, the water quality of the Una Basin, as indicated by the absence of acute toxicity, still remains in an acceptable conservation condition. Caution is needed, however, since slight pollution sources are causing chronic toxicity in some localities. In addition, as the microcrustacean C. dubia, appeared to be a reliable bioindicator in this investigation, we suggest that it be used for continuous water quality monitoring programs

    Composition, density, and shell use of hermit crabs (Crustacea: Paguroidea) from subtidal boulder fields in southeastern Brazil

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    Made available in DSpace on 2019-09-12T16:26:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2018ABSTRACT Hermit crabs are common and abundant members of the intertidal community and in sublittoral bottoms, where they play a fundamental role in the trophic chain. This study aimed to determine the composition of the hermit crab fauna, to quantify the density in the natural environment, and to register shells use by main species from subtidal boulder fields, in an island off the southeastern Brazilian coast. Monthly samples were taken from March 2010 to February 2011 on boulder fields on Couves Island, Ubatuba, Brazil, during scuba diving daytime sessions. Three hundred and eighty-three crabs were collected by hand, in a quadrat of 20 m2 belonging to five species: Calcinus tibicen, Dardanus venosus, Pagurus brevidactylus, Paguristes tortugae, and Petrochirus diogenes. The highest densities were recorded for P. brevidactylus and P. tortugae. Hermit crabs occupied shells of 15 gastropod species. Cerithium atratum, Gemophos auritulus, and Morula nodulosa comprised more than 80% of the occupation. The heterogeneity of boulder fields of Couves Island, composed almost entirely of small refuges and crevices, favors the exploration of hermit crab species recorded here, which are characterized by small size. These results, combined with the findings of further studies, can contribute to the development of effective monitoring programs for decapod crustacean species.[Cobo, Valter José] UNITAU, BrazilAlves, Douglas Fernandes Rodrigues] Universidade Federal de Sergipe, BrazilLima, Daniel José Marcondes] Universidade de São Paulo, Brazi

    Comparison of the population biology of Epialtus bituberculatus from two rocky shores with distinct hydrodynamic patterns

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    The population biology of Epialtus bituberculatus was compared between two different intertidal localities with differing levels of wave exposure. Sampling was conducted monthly between January and December, 2001 on seaweed banks of Sargassum cymosum in the intertidal zone of the rocky shores Grande (GR) (23°23′S-45°03′W) and Domingas Dias (DD) (23°29′S-45°08′W). Four hundred and twenty-eight crabs were captured at the GR site: 111 juvenile males, 106 adult males, 57 juvenile females, 17 adult females and 137 ovigerous females; while 455 specimens were obtained at the DD site: 76 juvenile males, 113 adult males, 37 juvenile females, 40 adult females and 189 ovigerous females. The population from GR showed a non-normal distribution and from DD a normal distribution. The sex-ratio (female/male) was 1:0.97 at GR (χ2 = 0.77, P = 0.084), whereas it was 1:1.41 at DD (χ2 = 13.03, P < 0.001). The largest individuals occurred at DD (U = 78249.0, P < 0.001). The estimated size at sexual maturity was 6.3 and 5.0 mm carapace width (CW) for males, and 5.4 and 5.2 mm CW for females, from GR and DD, respectively. The observed differences in E. bituberculatus between the studied localities might be explained by the different degrees of wave exposure between sites. However, other factors that might also explain the observed differences (e.g. temperature, salinity and food availability) cannot be discarded as relevant in influencing the population structure between sites herein studied. © 2012 Marine Biological Association of the United Kingdom

    Population dynamics of the mud crab Panopeus austrobesus Williams, 1983 (Brachyura: Panopeidae) associated with a mussel farm at the southeastern Brazilian coast

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    Made available in DSpace on 2019-09-11T20:58:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2017Abstract Mussel farms are one of the most important modalities of aquaculture and constitute almost 80% of the total bivalve production in Brazil, representing about 5% of the national production. Brachyuran crabs are common inhabitants of these environments and represent an important link in coastal marine food chains. The aim of this investigation is to describe the population structure of Panopeus austrobesus Williams, 1983 in a Perna perna (Linnaeus, 1758) farm located at the southeastern Brazilian coast. The samplings were carried out in the northeastern coast of São Paulo State. From May 2002 to April 2003, one mussel net was recovered monthly, and all individuals of P. austrobesus were collected. Population size-frequency analysis indicated a unimodal and non-normal distribution. Males were significantly larger than females, and the overall sex ratio significantly skewed from 1:1, female-biased. Recruitment occurred during the entire period, and ovigerous females were found in 11 months. The onset of sexual maturity was estimated around 5 mm cephalothorax width. Mussel farms represent an anthropogenic intervention in the sea landscape, causing environmental changes. However, these structures must allow species introduction, increasing their ecological and geographical distribution, and provide available space and food to establish new populations. This is particularly important for species with small populations, such as P. austrobesus. The results of this study attest the environmental counterpart role of the mussel farms. Once they can support populations, they may also help to reintroduce them into the area and could therefore be used in a consortium generating economic profits and acting as bioremediation tool, assuring the maintenance of the genetic patrimony.[Cobo, Valter José] Universidade de Taubaté, BrazilLima, Daniel José Marcondes] Universidade Estadual Paulista, BrazilCamargo, Flavio de Vasconcelos] Fundação de Ensino e Pesquisa de Itajubá, BrazilAlves, Douglas Fernandes Rodrigues] Universidade Federal de Sergipe, Brazi

    Population dynamics of the mud crab Panopeus austrobesus Williams, 1983 (Brachyura: Panopeidae) associated with a mussel farm at the southeastern Brazilian coast

    No full text
    Abstract Mussel farms are one of the most important modalities of aquaculture and constitute almost 80% of the total bivalve production in Brazil, representing about 5% of the national production. Brachyuran crabs are common inhabitants of these environments and represent an important link in coastal marine food chains. The aim of this investigation is to describe the population structure of Panopeus austrobesus Williams, 1983 in a Perna perna (Linnaeus, 1758) farm located at the southeastern Brazilian coast. The samplings were carried out in the northeastern coast of São Paulo State. From May 2002 to April 2003, one mussel net was recovered monthly, and all individuals of P. austrobesus were collected. Population size-frequency analysis indicated a unimodal and non-normal distribution. Males were significantly larger than females, and the overall sex ratio significantly skewed from 1:1, female-biased. Recruitment occurred during the entire period, and ovigerous females were found in 11 months. The onset of sexual maturity was estimated around 5 mm cephalothorax width. Mussel farms represent an anthropogenic intervention in the sea landscape, causing environmental changes. However, these structures must allow species introduction, increasing their ecological and geographical distribution, and provide available space and food to establish new populations. This is particularly important for species with small populations, such as P. austrobesus. The results of this study attest the environmental counterpart role of the mussel farms. Once they can support populations, they may also help to reintroduce them into the area and could therefore be used in a consortium generating economic profits and acting as bioremediation tool, assuring the maintenance of the genetic patrimony
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