978 resultados para Lucifer (Crustacea)


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The abundance and ecological distribution of Acetes americanus and Peisos petrunkevitchi were investigated from July 2006 to June 2007, in Ubatuba, Brazil. Eight transects were identified and sampled monthly: six of these transects were located in Ubatuba bay, with depths reaching 21 m, and the other two transects were in estuarine environments. A total of 33,888 A. americanus shrimp were captured, with the majority coming from the shallower transects (up to 10 m). Conversely, 6,173 of the P. petrunkevitchi shrimps were captured in deeper areas (from 9 to 21 m). No individuals from either species were found in the estuary. The highest abundances obtained for both species were sampled during the summer. Canonical correlation analysis resulted in a coefficient value of 0.68 (P = 0.00). The abundance of both species was strongly correlated with depth. Variations in temperature and salinity values were also informative in predicting the seasonal presence of P. petrunkevitchi in deeper areas and A. americanus in the shallower areas of the bay. It is conceivable that the shrimp adjust their ecological distribution according to their intrinsic physiological limitations. © 2012 Marine Biological Association of the United Kingdom.

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Some crustaceans show variations of their reproductive biology within their geographical distribution, and knowledge about such variations is important for the comprehension of their reproductive adaptations. This study compared two populations of the fiddler crab Uca uruguayensis from two locations on the south-western Atlantic coast: Ubatuba Bay, São Paulo, Brazil and Samborombón Bay, Buenos Aires, Argentina. The population features analysed were the body size variation (carapace width = CW) and the size at the onset of sexual maturity (SOM) in order to test the hypothesis that the size at SOM, should be the same in relative terms (RSOM), independently of the latitudinal position. In the Brazilian population the CW ranged from 4.18 to 11.60 mm for males and 3.90 to 9.80 mm for females, and in the Argentinean population from 3.60 to 14.10 mm for males and 2.85 to 12.00 mm for females. In the Brazilian population the SOM was 7.1 (RSOM = 0.58) and 5.9 mm CW (RSOM = 0.57) for males and females, respectively, and in the Argentinean population it was 7.0 (RSOM = 0.42) and 6.75 mm CW (RSOM = 0.53) for males and females, respectively. This fact is probably related to a great plasticity in the life history features of Uca uruguayensis under different environmental conditions. © 2012 Marine Biological Association of the United Kingdom.

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The present study presents a taxonomic review of Palaeolimnadiopsis suarezi Mezzalira described in Bauru Group. The geographic and stratigraphic distribution of the genus Palaeolimnadiopsis is widespread, including occurrences in several countries as Brazil, Bolivia, Chile, Uruguay, USA, Congo, China, Australia, Tasmania, Russia, Germany, Scottland, France and Belgium, in rocks from the Devonian to the Cretaceous. This taxon was probably eurytopic, with a high dispersal potential and very conservative in evolution. One specimen identified as Palaeolimnadiopsis sp. is much larger than the average (~3.5 cm long), presenting relatively wide and few growth bands. The gigantism of this specie may be related to conditions that excluded potential predators and competitors from the environment, as is indicated by the presence of more saline and/or alkaline water conditions than in normal fresh water suggested a relatively high proportion of carbonates in that region and stratigraphic interval. © 2013 by the Sociedade Brasileira de Paleontologia.

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This is a histological and histochemical analysis of the terminal portion of the female reproductive system and genital ducts of the blue land crab (Cardisoma guanhumi). Animals were collected in the Jaguaribe estuary (Ceará, Brazil) and dissected. Genital duct fragments were fixed and submitted to different staining techniques. The female reproductive system consists of a pair of ovaries and a pair of genital ducts. In the mid-posterior portion of each lobe, the ovaries communicate with the genital ducts, which are subdivided into oviduct, spermatheca, vagina, and gonopore. Histologically, the spermatheca of C. guanhumi is composed of columnar secretory epithelium and is divided into a dorsal zone and a ventral zone, the latter covered internally by a cuticle layer. Both zones are enveloped by a thin layer of loose connective tissue. Histological cross sections revealed the vagina to be concave, a pattern considered phylogenetically more advanced than the simple, tubular form. Our findings suggest fertilization is internal, favoring sperm from the most recent copulation. © 2012 The Authors. Acta Zoologica © 2012 The Royal Swedish Academy of Sciences.

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The reproductive biology of a species includes factors beyond its sexual maturity, fecundity and reproductive period, and may extend to the differential distribution of individuals. The reproductive dynamics of the blue crab Callinectes ornatus was investigated through monthly collections over the course of 2 years in three bays on the southeastern coast of Brazil. For each bay, six transects were established, four of them parallel to the beach line (at depths of 5, 10, 15, and 20 m), one transect exposed to wave action, and another sheltered from waves. Females and males were classified according to the gonadal maturation stage, and were grouped as individuals with reproductive potential (mature gonads or breeding females) or not (rudimentary gonads or in development). Analyses using ordination techniques (PCA) and gradient analysis (CCA) showed that 82.13 % of environmental variations were explained by the transect arrangement, and these characteristics explained 86.70 % of the differential distribution of female crabs and 96.57 % of the distribution of males. These results indicate that females with reproductive potential were more abundant in deeper regions, while females with rudimentary or developed gonads were abundant in shallower habitats and areas sheltered from wave action. Thus, the distribution of C. ornatus in these bays was linked to their reproductive state, as part of the reproductive strategy of the population. © 2013 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg.

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In Brazil, the state of São Paulo contains both preserved areas (Juréia-Itatins Ecological Station) and extremely impacted ones (Cubatão Municipality). This study evaluated the concentrations of five metals (Cu, Cd, Cr, Pb, and Hg) in two mangroves with different levels of anthropogenic impact and the apparent genotoxicity to Ucides cordatus. Water and sediment samples were obtained, and metal concentrations were determined with an atomic absorption spectrophotometer. The genotoxic impact was quantified based on the number of micronucleated cells per 1,000 analyzed (MN‰), using hemolymph slides stained with Giemsa. Metal concentrations in water were below the detection limit, except for lead, although no significant difference was observed between the areas (P > 0.05). Sediment from Cubatão had higher concentrations of Cd, Pb, Cr, and Cu than sediment from Juréia-Itatins (P < 0.05), but no significant differences in metal concentrations were detected among depth strata of the sediment (P > 0.05). Crabs from Cubatão had a 2.6 times higher mean frequency of micronucleated cells (5.2 ± 1.8 MN‰) than those from Juréia-Itatins (2.0 ± 1.0 MN‰; P < 0.0001). The more-polluted conditions found in the mangrove sediments of Cubatão were reflected in the micronucleus assay, demonstrating their genotoxic effect; however, genetic damage should be attributed to a synergistic effect with other kinds of pollutants previously recorded in different environments of Cubatão. U. cordatus proved to be an excellent bioindicator of mangrove pollution. This study established, for the first time, the normal frequency of MN‰ in a population of this species within an ecological station. © 2013 Springer Science+Business Media Dordrecht.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)