Marine anomurans (Decapoda) from the non-consolidated sublittoral bottom at the southeastern coast of Brazil

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

Population features of the spider crab Acanthonyx scutiformis (Dana 1851) (Crustacea, Majoidea, Epialtidae) associated with rocky-shore algae from southeastern Brazil.

Acanthonyx scutiformis, an endemic species in the Brazilian coast, is commonly found in intertidal rocky-shore algal communities. This study analyzes the population biology of A. scutiformis from Ubatuba region. A total of 371 specimens were collected over one year. Size range was 4.2[long dash]12.7 mm CW (carapace width) for females and 3.7[long dash]15.8 mm CW for males. Females predominated in intermediate size classes, whereas males prevailed in the largest ones. The estimated size when 50% crabs were mature was 10.7 mm CW for males and 8.9 mm CW for females. Sex ratio varied among the demographic groups. The processes that influence A. scutiformis population structure can be related to the different times males and females reach sexual maturity and probably to the distinct predation pressures on each sex during the adult phase.

The invasion of five alien species in the Delta do Parnaiba Environmental Protection Area, Northeastern Brazil

Marine biological invasions have been regarded as one of the major causes of native biodiversity loss, with shipping and aquaculture being the leading contributors for the introductions of alien species in aquatic ecosystems. In the present study, five aquatic alien species (one mollusk, three crustaceans and one fish species) were detected during dives, shore searches and from the fisheries on the coast of the Delta do Parnaiba Environmental Protection Area, in the States of Piaui and Maranhao, Northeastern Brazil. The species were the bicolor purse-oyster Isognomon bicolor, the whiteleg shrimp Litopenaeus vannamei, the giant river prawn Macrobrachium rosenbergii, the Indo-Pacific swimming crab Charybdis hellerii and, the muzzled blenny Omobranchus punctatus. Ballast water (I. bicolor, C. hellerii, and O. punctatus) and aquaculture activities (L. vannamei and M. rosenbergii) in adjacent areas are the most likely vectors of introduction. All exotic species found have potential impact risks to the environment because they are able to compete against native species for resources (food and habitat). Isognomon bicolor share the same habitat and food items with the native bivalve species of mussels and barnacles. Litopenaeus vannamei share the same habitat and food items with the native penaeids such as the pinkspot shrimp Farfantepenaeus brasiliensis, the Southern brown shrimp Farfantepenaeus subtilis, and the Southern white shrimp Litopenaeus schmitti, and in the past few years L. vannamei was responsible for a viral epidemics in the cultivation tanks that could be transmitted to native penaeid shrimps. Charybdis hellerii is also able to cause impacts on the local fisheries as the species can decrease the populations of native portunid crabs which are commercialized in the studied region. Macrobrachium rosenbergii may be sharing natural resources with the Amazon River prawn Macrobrachium amazonicum. Omobranchus punctatus shares habit with the native redlip blenny Ophioblennius atlanticus and other fishes, such as the frillfin goby Bathigobius soporator. Some immediate remedial measures to prevent further introductions from ballast water and shrimp farm ponds should be: (i) to prevent the release of ballast water by ship/vessels in the region; (ii) to reroute all effluent waters from shrimp rearing facilities through an underground or above-ground dry well; (iii) to install adequate sand and gravel filter which will allow passage of water but not livestock; (iv) outdoor shrimp pounds located on floodable land should be diked, and; (v) to promote environmental awareness of those directly involved with ballast water (crews of ship/vessels) and shrimp farms in the region. Rev. Biol. Trop. 58 (3): 909-923. Epub 2010 September 01.

Occurrence of freshwater stingrays (Chondrichthyes: Potamotrygonidae) in the Uruguay River and its tributaries, Uruguay, South America.

Four records of potamotrygonids in the Uruguay River and its tributaries in Paysandu, Uruguay are reported in this paper. The first one was a specimen caught in 1934, of undetermined sex and weighing 120 kg and with a disc width of ca 150 cm. The second specimen, caught in 1998, was also of undetermined sex; it weighed 50 kg total weight and its disc width measured 103 cm. The third specimen was caught in 2001; it was an adult male, weighed 114 kg total weight and its disc width measured ca 110 cm. The fourth one, caught in 2004, was a female, 11 kg in total weight and with a disc width of 80 cm. According to the size and general description, specimens were identified as Potamotrygon brachyura, to date the only potamotrygonid confirmed for Uruguay.

Food resource utilization of the skates Rioraja agassizii (Müller & Henle, 1841) and Psammobatis extenta (Garman, 1913) on the continental shelf off Ubatuba, South-eastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Use of the freshwater crab Trichodactylus fluviatilis to biomonitoring Al and Mn contamination in river water.

Determinations of Al and Mn concentrations in the tissues (gills, hepatopancreas and muscle) of the freshwater crab Trichodactylus fluviatilis and water samples, both collected from sites on tributaries of the Corumbatai River (São Paulo, Brazil) were performed. The Bioaccumulation Factor (BAF), calculated for different sites with respect to the water concentration, ranged from 173-555 for Al and from 636 - 921 for Mn. Dissolved concentrations of Al and Mn in water samples (collected in different sites) were related to the accumulation of these metals in crabs, suggesting that T. fluviatilis is good biomonitor for Al and Mn pollution in aquatic ecosystem.

Bioecology of the uçá-crab, Ucides cordatus (Linnaeus, 1763), in Vitória Bay, Espírito Santo State, Brazil

A biologia de Ucides cordatus na Baía de Vitória (ES) foi avaliada como subsídio ao manejo populacional. As amostragens ocorreram mensalmente durante um ano (outubro/1998 a setembro/1999), com análise biométrica (LC = largura da carapaça; PE = peso total úmido) e de fatores abióticos em quatro transectos, com quatro faixas cada (margem à região supratidal). A densidade foi de 3,7±1,5 caranguejos.m-2, com incremento em direção à região supratidal, sendo a profundidade das galerias de 1,1±0,3 m. A salinidade da água intersticial diferiu entre as faixas, sendo mais elevada na região supratidal. Houve correlação significativa entre a abundância de exemplares e alguns fatores ambientais, o mesmo ocorrendo quanto as tocas abertas e fechadas. A razão sexual evidenciou um predomínio de fêmeas (1,0M:1,6F), particularmente entre 50 e 75 mm LC. A maior incidência de tocas fechadas ocorreu em agosto e setembro, enquanto as fêmeas ovígeras foram registradas de janeiro a abril. A relação PE/LC mostrou isometria para os machos (PE=0,425.10-3 LC3,0014; R²=0,99) e fêmeas (P=0,439.10-3 LC2,97; R²=0,99). Para o total da população a média de tamanho (LC) e peso (PE) foi de 54,6±11,8 mm e de 77,5±42,4 g, respectivamente. Os dados evidenciam que a população encontra-se sobrexplotada, requerendo manejo adequado para a viabilidade da atividade extrativa na área estudada.

Shell utilization pattern of the hermit crab Clibanarius vittatus (Crustacea, Anomura) in an estuary at São Vicente, State of São Paulo, Brazil

O objetivo do presente estudo foi avaliar a utilização de conchas de gastrópodes por Clibanarius vittatus (Bosc, 1802), na Praia dos Pescadores, em São Vicente (SP), Brasil. Foram realizadas amostras mensais no período de maio de 2001 a abril de 2003, na região intertidal durante a maré baixa. Todos os animais foram pesados e tiveram o comprimento de seu escudo cefalotorácico mensurados, suas conchas identificadas e medidas quanto ao comprimento (mm), abertura (mm) e peso (g). Capturamos 2.344 ermitões (644 machos, 1.594 fêmeas não-ovígeras, 45 fêmeas ovígeras e 61 em intersexo), utilizando 13 espécies de conchas de gastrópodes, das quais Stramonita haemastoma (Linnaeus, 1767), Cymatium parthenopeum (Von Salis, 1793) e Achatina fulica (Bowdich, 1822) representaram mais de 98% das conchas utilizadas. Obteve-se significativa diferença de tamanho entre os sexos, com machos e indivíduos em intersexo atingindo maior porte físico do que fêmeas. Este padrão influenciou fortemente na ocupação e utilização de conchas, principalmente em A. fulica, que foi a maior concha obtida por C. vittatus, utilizada somente por machos e indivíduos em intersexo. Cymatium parthenopeum foi a única espécie de concha em que se obtiveram elevados coeficientes de determinação para todas os parâmetros analisados. Stramonita haemastoma apresentou elevados e significativos coeficientes de determinação, indicando que esta espécie é o principal recurso de concha ocupada na Praia dos Pescadores.

Desenvolvimento juvenil de Hepatus pudibundus (Herbst) (Crustacea, Decapoda, Calappidae), em laboratório

The Hepatus pudibundus (Herbst, 1785) juvenile development was studied in laboratory, under the morphological and systematical stand points. The eight early juvenile stages were obtained from larvae hatched from eggs of two ovigerous females, collected at the northern coast of the State of São Paulo, Brazil. The experiments were carried out in a climatically controlled room at 25 ± 1°C, and steady saltness of 34 . The youngs were maintened individually and food consisted of Artemia sp. nauplii and fragments of fish muscle.The first juvenile stage were particulary drawn and described. For the remaining juvenile stages the most representative frameworks were picked out, which allowed the characterization of the first eight stages. According to juvenile morphology studies, it was noted that secondary sexual characters differentation begins from the third stage.

Estrutura populacional de Callinectes ornatus Ordway (Crustacea, Portunidae) no Balneário Shangri-Lá, Pontal do Paraná, Paraná, Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relação peso/largura da carapaça e fator de condição em Dilocarcinus pagei Stimpson (Crustacea, Trichodactylidae), em São José do Rio Preto, São Paulo, Brasil

A biologia de caranguejos de água doce tem sido pouco enfocada na literatura carcinológica, especialmente em relação à Dilocarcinus pagei Stimpson, 1861. Este estudo visa analisar a relação peso/tamanho e variações temporais/sazonais do fator de condição, comparando com a biologia da espécie. Os exemplares foram coletados mensalmente na Represa Municipal de São José do Rio Preto (São Paulo), durante um período bianual (outubro/1994 a setembro/1996). Foram obtidos 962 espécimes (534 machos e 428 fêmeas), que foram mensurados (LC = largura do cefalotórax) e pesados (PE = peso úmido total). Os pontos empíricos da relação PE/LC foram analisados para cada sexo e submetidos à análise de regressão pela função potência (y = ax b) e representadas por: PE Machos = 0,0002LC3,º8 e PE Fêmeas = 0,0005LC2,82. O fator de condição foi calculado mensal e sazonalmente, sendo o das fêmeas cerca de 2,5 maior que o dos machos, possivelmente devido ao maior tamanho/peso das gônadas. de modo geral o verão foi caracterizado pela menor média de fator de condição (época reprodutiva), contrastando com a maior verificada no inverno (reorganização gonadal). Os resultados obtidos são enfocados pela primeira vez na literatura carcinológica, sendo de grande valia no manejo populacional e preservação desta espécie, que vem sendo intensamente explorada e usada como isca na pesca esportiva.

Appraisal of the chelipeds size on Hepatus-pudibundus (Herbst, 1785) (Crustacea, Calappidae) in function of sex and maturation

This paper appraises the influence of chelipeds on sexual and maturation phasis of the crab Hepatus pudibundus (Herbst, 1785), collected in Ubatuba (SP) region. The allometric constants obtained from the regression (carapace width X cheliped weight) adjusted to a power function (Y=aX(b)) were analysed. It was verified that males show larger chelipeds than females. The mean percentage of the chelipeds weight differs in sex and maturation.

Epibiosis and molting in two species of Callinectes (Decapoda: Portunidae) from Brazil

The external infestation of Callinectes ornatus Ordway, 1863 and Callinectes danae Smith, 1869, in particular cirripeds, was studied for two consecutive years in the Ubatuba Bay (SP) (23 degrees 26' S and 45 degrees 02' W). Bryozoans, polychaetes and cirripeds were found on both swimming crab species, but cirripeds were the most abundant and frequent. The number of infested swimming crabs increased proportionally to carapace size, but not surpassing 30 %, suggesting an absence of terminal anecdysis in both species. The establishment of the pernicious organisms on their hosts is influenced by other factors, such as their habit of burying themselves in sediments. The correlation between molting activity in adult specimens of both sexes and the low incidence of epizoonts suggest that C. ornatus and C. danae may be molting after maturity.

Relative growth of spider crab Acanthonyx scutiformis (Dana, 1851) (Crustacea, Decapoda, Majidae)

The dimensions of chelar propodus and abdomen were utilized for the morphometric analysis about the relative growth studies of Acanthonyx scutiformis (Dana, 1851). A total of 297 specimens (114 males and 183 females), was collected in Ubatuba, State of São Paulo, Brazil. The animals were sexed and soarted to maturation phase (immature and mature). The following measurements were made: carapace (length and width), abdomen width and chelar propodus (length and height). In this study was applicated the power function (y= a.x(b)), in which the growth was considered positive allometric with isometric with b=1, and negative allometric with b<1. The alometry becomes isometric, when the results concerning immature and mature females and males are analysed. In the Brachyura male chelipeds are utilized in territorial defense, fight, display and courtship and female abdomens are utilized as a chamber that protect and incubate the eggs.

Notes on the feeding habits of the skate Rioraja agassizi (Chondrichthyes, Rajidae) off southeastern Brazil

Feeding habits of the skate Rioraja agassizi were analyzed in southeastern Brazil from samples obtained along Silo Paulo coast. A total of 258 specimens were examined, ranging between 96 and 532 mm total length. About 57.85% were females and 42.15% were males, resulting in a 1:1.37 sex-ratio to females. From 223 stomachs collected (94 males and 129 females) empty stomachs represented only 1.4%. Nine prey categories were identified: Polychaeta, Copepoda, Cumacea, Isopoda, Gammaridea, Dendrobranchiata, Brachyura, Teleostei, and one non-animal category (non-identifiable items). Crustaceans were the most important item, indicating that the species has a carcinophagic preference. The presence of fish was just verified in juveniles and some adult individuals, with predominance in summer. Sex, maturity stage and seasonality did not influence the feeding habits of the species.