30 research outputs found
Juvenile development of Callinectes danae Smith, 1869 (Crustacea, Decapoda, Brachyura, Portunidae) under laboratory conditions
Morphology of the first zoeal stages of five species of the portunid genus Callinectes (Decapoda, Brachyura) hatched at the laboratory
Composition and abundance of shrimp species (penaeidea and caridea) in Fortaleza Bay, Ubatuba, São Paulo, Brazil
The abundance and spatio-temporal distribution of the caridean and penaeid fauna from Fortaleza Bay, Ubatuba, São Paulo, Brazil, were analyzed. Seven transects were sampled over a one year period from November 1988 to October 1989. A total of 17047 shrimps were captured, representing 13 species belonging to 5 families. The interaction of temperature and type of sediment was fundamental in determining the presence and abundance of shrimp species in the area
Morphometric study of the ghost crab Ocypode quadrata (Fabricius, 1887) (brachyura, ocypodidae) from Ubatuba, São Paulo, Brazil
A morphometric study of the ghost crab Ocypode quadrata from Ubatuba, São Paulo, Brazil, focusing on the relationships between carapace width and carapace length, abdomen width, gonopod length and propodus length and height of the major cheliped is presented. An allometric positive growth was found for most of the analyzed relationships; however, important changes in the gonopod and abdomen were observed at the size at which sexual maturity is attained. Morphological (external) sexual maturity for both sexes is achieved at a smaller size than that at which gonad maturity is reached. Concerning heterochely, 53.3% of the analyzed specimens exhibited a longer propodus length in the right cheliped
Diversity of decapod crustaceans at the interface of unconsolidated seabed areas and rocky shores in tropical/subtropical Brazil
The population structure of two sympatric hermit-crab species on a subtidal rocky shore of an island in southeastern Brazil
Ecological aspects of hermit crabs (Crustacea, Anomura, Paguroidea) off the northern coast of São Paulo State, Brazil
Breeding season of the hermit crab petrochirus diogenes (anomura : diogenidae) in the north coast of São Paulo state, Brazil
Petrochirus diogenes, one of the largest hermit crabs in the western Atlantic, was studied in the north coast of the State of São Paulo, Brazil, to determine its breeding season through the analysis of gonad development at a macroscopic level. The analysis of 999 crabs collected from 1995 to 1999, based on four categories of gonad development, showed that males present gonads in the advanced stage during all seasons, and although females present developed ovaries all year as well, the peak incidence is in the summer. The peak of recruitment occurs in the winter
Diel variation in abundance and size of the seabob shrimp Xiphopenaeus kroyeri (Crustacea, Penaeoidea) in the Ubatuba region, Southeastern Brazil
The objective of the present study was to analyze diel variation in the abundance and size of the seabob shrimp Xiphopenaeus kroyeri in the Ubatuba region, state of São Paulo, during the year 2000. In each season of the year, collections were made in the day and at night on 9 transects at depths ranging from 2 to 40 m. The estimated shrimp amount was of 28,878 individuals. Although the catch rate was higher during the day (15,853 shrimp), this did not differ significantly from the catch at night (13,025). The catch rate was higher in daytime on most transects, but was higher at night at locations where fine and very fine sand predominated. The majority of juveniles were caught during the day. The mean size (CL) was 14.43 ± 4.02 mm for day and 14.82 ± 4.28 mm for night samples, and the difference was significant (Student's t-test, df = 2, 429, t = 2.27, p = 0.02). The largest individuals were caught during the night. None of the three models that have been proposed in the literature to account for differences in the diurnal catch pattern of penaeid species can be applied to X. kroyeri. Our results provide evidence that sediment type not only influenced the catch rate in the analyzed periods, but also determined which models might fit the behavior of this species.<br>O objetivo do presente estudo foi analisar a variação diuturna na abundância e no tamanho do camarão sete-barbas Xiphopenaeus kroyeri na região de Ubatuba/São Paulo, durante o ano 2000. Em cada estação do ano, as coletas foram realizadas no período diurno e noturno, em 9 transectos localizados nas profundidades de 2 a 40 m. Um total de 28.878 camarões foi obtido e apesar da maior taxa de captura observada durante o dia (15.853 camarões), não houve diferença significativa em relação ao período noturno (13.025). Na maioria dos tran-sectos houve também uma maior taxa de captura de camarões durante o dia, no entanto, verificou-se que em locais com sedimentos com predominância de areia fina e muito fina, houve uma captura no período noturno. Já em relação aos juvenis, a maioria dos indivíduos foi amostrada durante o dia. Em consideração ao tamanho (CC) médio, obteve-se o valor de 14,43 ± 4,02 mm durante o dia e 14,82 ± 4,28 mm durante a noite, com significativa diferença (Student's t-test, df = 2.429, t = 2,27, p = 0,02). Verificou-se também que os maiores indivíduos foram capturados no período noturno. Um único modelo dos três propostos na literatura para as espécies de peneídeos quanto ao padrão de captura diuturna não pode ser aplicado ao X. kroyeri. Nossos resultados evidenciaram que tipo de sedimento não somente influenciou na taxa de captura entre os períodos analisados como determinou os modelos em que esta pode ser incluída