43 resultados para brachyura crabs


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The relative growth and morphological sexual maturity of Chasmagnathus granulatus Dana, 1851 are presented for the first time to a mangrove population. The crabs were obtained during low tide periods, in the mangrove of Jabaquara Beach, Paraty, Rio de Janeiro, Brazil. All crabs in intermolt stage were sexed and had their body parts measured as follows: body height (BH), carapace length (CL) and width (CW), major cheliped propodus height (PH) and length (PL) for each sex, gonopod length (GL) and abdomen width (AW) for males and females, respectively. The relative growth was described using the allometric equation y=ax b and the size at onset sexual maturity was achieved using the software Mature I. The size of specimens ranged from 4.1 mm to 39.5 mm CW. The growth pattern was different between sexes in the cheliped relationships; the relationships BH vs. CW evidenced positive allometry for juveniles; PL vs. CW and PH vs. CW positive allometry for most crabs except juvenile females; AW vs. CW and GL vs. CW evidenced positive allometry for juveniles and isometry for adults. The relationships that best indicated the change from the juvenile to the adult phase were PH vs. CW for males and AW vs. CW for females. The size in which 50% of males from this population are mature is at 19.7 mm of CW (F=144.14; p<0.05) and for females it is at 19.2 mm of CW (F=166.54; p<0.05). The sizes obtained in this mangrove population are larger than those from previous studies, that could be attributed to a species plasticity concerning the habitat structure.

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Utilizando o método de deslocamento modal para a identificação das idades, estimou-se o crescimento do siri-azul Callinectes sapidus Rathbun, 1896 em duas áreas de pesca no estuário da Lagoa dos Patos. Os indivíduos foram coletados entre fevereiro de 2005 e março de 2006 no Saco da Mangueira e Saco do Arraial por meio de arrasto de rede de portas da pesca artesanal. Coletou-se um total de 2.609 animais, sendo 1.193 machos e 1.416 fêmeas. Para obtenção das curvas de crescimento utilizou-se o modelo de von Bertalanffy. As curvas foram validadas pela sua adequação ao ciclo de vida e aspectos biológicos da espécie. O tamanho máximo de largura de carapaça (LCmáx) utilizado foi mantido fixo em todas as análises (LCmáx=162,71mm; ± d.p.=3,10 para machos e LCmáx=157,78mm; ± d.p.=5,45 para fêmeas), sendo esses valores médios das maiores medidas obtidas em mais de 20 anos de coletas no estuário. Os parâmetros de crescimento e longevidade foram estimados para machos (Saco da Mangueira, K=0,0039/dia; t o=-6.07; 1.195 dias; Saco do Arraial, K=0,0041/dia; t o=-5,84; 1.102 dias) e fêmeas (Saco da Mangueira, K=0,0040/dia; t o=-6,22; 1.153 dias; Saco do Arraial, K=0,0039/dia; t o=-5.91; 1.181 dias). As curvas de crescimento estimadas nesse trabalho denotam que a espécie atinge o tamanho mínimo de captura praticamente no primeiro ano de vida (120mm).

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The structure of the male reproductive tract was described in Uca uruguayensis Nobili, 1901, by using histological methods, scanning electron microscopy techniques, and stereoscopic observations of fresh material. The aim of this work was to establish the functional changes associated with sexual maturation. The morphology of the first (G1) and second (G2) pair of gonopods was described. The male reproductive tract consists of paired organs: testes, and tubular and convoluted vas deferens (VD) ending with a terminal ampoule (TA).The (VD) is composed of three parts: anterior (AVD), medial (MVD) and posterior (PVD). The AVD and MVD are lined by a single layer of cubical cells. The PVD epithelial cells are columnar with elongated nuclei. The terminal ampoule comprises four interconnecting chambers and is externally surrounded by connective tissue. The study of testes and vas deferens at different times along the year suggests that U. uruguayensis has a single and continuous reproductive season from December to March. The TA has not been described in other brachyurans and this structure is novel to Brachyura.

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The present contribution aims at evaluating the carapace width vs. humid weight relationship and the condition factor of Ucides cordatus (Linnaeus, 1763), in the mangrove forests of the Ariquindá and Mamucabas rivers, state of Pernambuco, Brazil. These two close areas present similar characteristics of vegetation and substrate, but exhibit different degrees of environmental conservation: the Ariquindá River is the preserved area, considered one of the last non-polluted of Pernambuco, while the Mamucabas River suffers impacts from damming, deforestation and deposition of waste. A total of 1,298 individuals of U. cordatus were collected. Males were larger and heavier than females, what is commonly observed in Brachyura. Ucides cordatus showed allometric negative growth (p < 0.05), which is probably related to the dilatation that this species develops in the lateral of the carapace, which stores six pairs of gills. The values of b were within the limit established for aquatic organisms. Despite of the condition factor being considered an important feature to confirm the reproductive period, since it varies with cyclic activities, in the present study it was not correlated to the abundance of ovigerous females. However, it was considered a good parameter to evaluate environmental impacts, being significantly lower at the impacted area.

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The semi terrestrial crabs are important elements of the fauna of coastal regions. The aim of this study was to analyze the population structure of Armases angustipes (Dana, 1852) at estuaries of the Ariquindá River, considered a non impacted area, and Mamucabas River, considered a few impacted area, on the south coast of state of Pernambuco, Brazil. The species occurred in all months of the year. The number of individuals per month varied, being higher in the months of transition between the seasons. This is probably due to significant seasonal variations of air and burrow temperature and burrow salinity. There was no sexual dimorphism in size of A. angustipes in the mangrove of Ariquindá River, but males were larger than females in the mangrove of Mamucabas River. In both estuaries, the sex ratio did not differ from Mendelian proportion, but showed a deviation for females. The analysis of temporal variation in sex ratio showed significant differences in some months of the year. These variations are due to cyclical events that act distinctly on each sex. In both estuaries, size classes of carapace width were equally represented by both sexes. The ovigerous females of A. angustipes occurred only in some months of the year, especially in summer, in both estuaries. Probably the high phytoplankton productivity observed in summer favors the reproductive activity, since these algae serve as food for the larvae. Specimens of the population of Rio Ariquindá are largest and wider than those of Mamucabas River. This fact, associated with the low abundance of crabs and the lower frequency of ovigerous females observed in Mamucabas River, is an indication that this population may be influenced by the environmental impacts that this estuary has received.

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Crustacean growth studies typically use modal analysis rather than focusing on the growth of individuals. In the present work, we use geometric morphometrics to determine how organism shape and size varies during the life of the freshwater crab, Aegla uruguayana Schmitt, 1942. A total of 66 individuals from diverse life cycle stages were examined daily and each exuvia was recorded. Digital images of the dorsal region of the cephalothorax were obtained for each exuvia and were subsequently used to record landmark configurations. Moult increment and intermoult period were estimated for each crab. Differences in shape between crabs of different sizes (allometry) and sexes (sexual dimorphism; SD) were observed. Allometry was registered among specimens; however, SD was not statistically significant between crabs of a given size. The intermoult period increased as size increased, but the moult frequency was similar between the sexes. Regarding ontogeny, juveniles had short and blunt rostrum, robust forehead region, and narrow cephalothorax. Unlike juveniles crabs, adults presented a well-defined anterior and posterior cephalothorax region. The rostrum was long and stylised and the forehead narrow. Geometric morphometric methods were highly effective for the analysis of aeglid-individual- growth and avoided excessive handling of individuals through exuvia analysis.

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This paper comprises: 1) A note on Systematists of fiddler crabs from the Bay of Rio de Janeiro, with its new species Uca olympioi, Uca salsisitus, and a new variety U. pugnax var. brasiliensis. 2) Female Uca characterization is easier and infuse certainness when we inquire her third maxillipod. 3) Redescriptions are made for type-locality animals at Rio de Janeiro and nearness. 4) Male characterization become possible through its maxillipod if we lose its quelipod. 5) A historical referendary originating into indigenous dialect « Guarany » about the name Uca and brasilian nicknames of the fiddler crabs. 6) A few Uca species from the Rio de Janeiro determinative keys asked after main distinctions among others species described over the world in paragraph « diagnose diferencial ». 7) A collected material catalogue and some mensurement tables.

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The author studied, the horizontal and vertical distribution of most common part of the flora and fauna of the bay of Guanabara at Rio de Janeiro. In this paper the eulittoral, poly, meso and oligohaline regions were localised and studied; and the first chart of its distribution was presented (fig. 2). The salinity of superficial waters was established through determinations based on 30 trips inside the buy for collecting biological materials. Some often 409 determinations which were previous reported together with the present ones served for the eleboration of a salinity map of the bay of Guanabara (fig. 1). This map of fig. 2 shows the geographic locations of the water regions. EULITTORAL WATER REGIME — Fig. 3 shows the diagram scheme of fauna and flora of this regime. Sea water salinity 34/1.000, density mean 1.027, transparent greenish waters, sea coast with moderate bursting waves. Limpid sea shore with white sand, gneiss with the big barnacle Tetraclita squamosa var. stalactifera (Lam. Pilsbry. Vertical distributions: barna¬cles layers with a green region in which are present the oyster Ostrea pa-rasitica L., the barnacles Tetraclita, Chthamalus, Balanus tintinnabulum var. tintinnabulum (L.) e var. antillensis Pilsbry in connection with several mollusca and the sea beatle Isopoda Lygia sp. Covered by water and exposed to air by the tidal ritms, there is a stratum of brown animals that is the layer of mussels Mytilus perna L., with others brown and chestnut animals : the Crustacea Pachygrapsus, the little crab Porcellana sp., the stone crab Me-nippe nodifrons Stimpson, the sea stars Echinaster brasiliensis (Mull. & Tr.), Astropecten sp. and the sea anemones Actinia sp. Underneath and never visible there is a subtidal region with green tubular algae of genus Codium and amidst its bunches the sea urchin Lycthchinus variegatus (Agass.) walks and more deeply there are numerous sand-dollars Encope emarginata (Leske). The microplancton of this regime is Ceratiumplancton. POLYHALINE WATER REGIMB — Water almost sea water, but directly influenced by continental lands, with rock salts dissolved and in suspension. Salinity: 33 to 32/1.000. This waters endure the actions of the popular nicknamed «water of the hill» (as the waters of mesohaline and oligohaline regimes), becoming suddenly reddish during several hours. That pheno¬menon returns several times in the year and come with great mortality of fishes. In these waters, according to Dr. J. G. FARIA there are species of Protozoa : Peridinea, the Glenoidinium trochoideum St., followed by its satellites which he thinks that they are able to secret toxical substances which can slaughter some species of fishes. In these «waters of the hill» was found a species of Copepoda the Charlesia darwini. In August 1946 the west shore of the Guanabara was plenty of killed fishes occupying a area of 8 feet large by 3 nautical miles of lenght. The enclosure for catching fishes in the rivers mouthes presents in these periods mass dead fishes. The phenomenon of «waters of the hill» appears with the first rains after a period of long dryness. MESOHALINE WATER REGIME — Fig. 4 shows the the diagramm scheme. Salt or brackish water from 30 to 17/1.000 salinity, sometimes until 10/1.000. Turbid waters with mud in suspension, chestnut, claveyous waters; shore dirty black mud without waving bursting; the waters are warmer and shorner than those of the polihaline regime. Mangrove shore with the mangrove trees : Rhizophora mangle L., Avicennia sp., Laguncularia sp., and the »cotton tree of sea» Hibiscus sp. Fauna: the great land crab «guaimú» Cardisoma guanhumi Latr., ashore in dry firm land. There is the real land crab Ucides cordatus (L.) in wetting mud and in neigh¬ bourhood of the burrows of the fiddler-crabs of genus Uca. On stones and in the roots of the Rhizophora inhabits the brightly colored mangrove-tree-crab («aratu» Portuguese nickname) Goniopsis cruentata (Latreille) and the sparingly the big oyster Ostrea rhizophorae Guild. Lower is the region of barnacles Balanus amphitrite var. communis Darwin and var. niveus Darwin; Balanus tintinnabulum var. tintinnabulum (L.) doesn't grow in this brackish water; lower is the region of Pelecipoda with prepollency of Venus and Cytherea shell-fishes and the Panopeus mud crab; there are the sea lettuce Ulva and the Gastreropod Cerithium. The Paguridae Clibanarius which lives in the empty shells of Gasteropod molluscs, and the sessile ascidians Tethium plicatum (Lesuer) appears in some seasons. In the bottom there is a black argillous mud where the «one landed shrimps» Alpheus sp. is hidden. OLIGOHALINE WATER REGIME — The salinity is lower than 10/1.000. average 8/1.000. There are no barnacles and no sea-beetles Isopods of genus Lygia; on the hay of the shore there are several graminea. This brackish water pervades by mouthes of rivers and penetrates until about 3 kilometers river above. While there is some salt dissolved in water, there are some mud crabs of the genus Uca, Sesarma, Metasesarma and Chasmagnatus. The presence of floating green plants coming from the rivers in the waters of a region indicated the oligohaline waters, with low salt content because when the average of NaCl increases above 8/1.000 these plants die and become rusty colored.

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Paragonimus rudis was found in the lungs of a giant otter Lutra (pteronura) brasiliensis by Natterer in 1828, who dissected the animal in the former capital Mato Grosso (=Vila Bela), Brazil. The flukes were described by Diesing in 1850, and redescribed by Braun in 1901. Both descriptions do not allow to identify the species. Therefore, P. rudis must be regarded a "nomen nudum". Because its rediscovery is desirable with regard to historical reasons and nomenclatoric questions, a field study was performed in Mato Grosso in 1980. Of 354 freshwater crabs from 24 localities collected and examined for parasitic infections, about 25% were found to be infected with 7kinds of trematode larvae, which differed distincly from Paragonimus-metacercariae. The question, whether P. rudis or other lung fluke species do not seem to occur or cannot be found any longer in the area investigated by us, is discussed.

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A review of national and international publications on paragonimiasis in Ecuador, epidemiological records from the Ministry of Public Health and unpublished research data was conducted to summarise the current status of the parasite/disease. The purpose of the review is to educate physicians, policy-makers and health providers on the status of the disease and to stimulate scientific investigators to conduct further research. Paragonimiasis was first diagnosed in Ecuador 94 years ago and it is endemic to both tropical and subtropical regions in 19 of 24 provinces in the Pacific Coast and Amazon regions. Paragonimus mexicanus is the only known species in the country, with the mollusc Aroapyrgus colombiensis and the crabs Moreirocarcinus emarginatus, Hypolobocera chilensis and Hypolobocera aequatorialis being the primary and secondary intermediate hosts, respectively. Recent studies found P. mexicanus metacercariae in Trichodactylus faxoni crabs of the northern Amazon. Chronic pulmonary paragonimiasis is commonly misdiagnosed and treated as tuberculosis and although studies have demonstrated the efficacy of praziquantel and triclabendazole for the treatment of human infections, neither drug is available in Ecuador. Official data recorded from 1978-2007 indicate an annual incidence of 85.5 cases throughout the 19 provinces, with an estimated 17.2% of the population at risk of infection. There are no current data on the incidence/prevalence of infection, nor is there a national control programme.

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The objective of this work was to select surviving breeders of Litopenaeus vannamei from white spot syndrome virus (WSSV) outbreak, adapted to local climatic conditions and negatively diagnosed for WSSV and infectious hypodermal and hematopoietic necrosis virus (IHHNV), and to evaluate if this strategy is a viable alternative for production in Santa Catarina, Brazil. A total of 800 males and 800 females were phenotypically selected in a farm pond. Nested-PCR analyses of 487 sexually mature females and 231 sexually mature males showed that 63% of the females and 55% of the males were infected with IHHNV. Animals free of IHHNV were tested for WSSV, and those considered double negative were used for breeding. The post-larvae produced were stocked in nine nursery tanks for analysis. From the 45 samples, with 50 post-larvae each, only two were positive for IHHNV and none for WSSV. Batches of larvae diagnosed free of virus by nested-PCR were sent to six farms. A comparative analysis was carried out in growth ponds, between local post-larvae and post-larvae from Northeast Brazil. Crabs (Chasmagnathus granulata), blue crabs (Callinectes sapidus), and sea hares (Aplysia brasiliana), which are possible vectors of these viruses, were also evaluated. The mean survival was 55% for local post-larvae against 23.4% for post-larvae from the Northeast. Sea hares showed prevalence of 50% and crabs of 67% of WSSV.

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Chitosan, poly[β-(1-4)-linked-2-amino-2-deoxy-D-glucose], is the N-deacetylated product of chitin which is a major component of arthropod and crustacean shells such as lobsters, crabs, shrimps, and cuttlefishes. In addition, chitosan has many significant biological and chemical properties such as biodegradability, biocompatibility and bioactivity as well as polycationic properties. Thus, it has been widely used in many industrial and biomedical applications including wastewater treatment, chromatographic support, carriers for controlled drug delivery and enzyme immobilization. This review is an insight into the exploitation of utilization of chitosan based-supports in different geometrical configurations on the immobilization of enzymes by different protocols for further application in biotransformation reactions.

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Whole body oxygen consumption and some hemolymph parameters such as pH, partial pressure of gases, level of ions and lactate were measured in the estuarine crab Chasmagnathus granulata after both acute (96 h) and chronic (2 weeks) exposure to cadmium at concentrations ranging from 0.4 to 6.3 mg/l. In all instances, the crabs developed hemolymph acidosis, but no respiratory (increased PCO2) or lactate increases were evident. Hemolymph levels of sodium and calcium were always increased by cadmium exposure. The chronic toxicity of cadmium was enhanced at 12‰ salinity, even causing a significantly higher mortality in comparison with the higher salinity (30‰) used. A general metabolic arrest took place at 12‰ salinity in the crabs chronically exposed to cadmium, as indicated by decreases of oxygen consumption and PCO2, an increase of PO2, along with no changes in lactate levels. These imbalances were associated with severe necrosis and telangiectasia in the respiratory gills, probably leading to respiratory impairment and finally histotoxic hypoxia and death of the animals.