RESUMO Este estudo descreveu os padrões reprodutivos e de recrutamento do siri Achelous spinimanus (Latreille, 1819) na região de Ubatuba, litoral norte de São Paulo, Brasil. Os siris foram coletados mensalmente, de janeiro de 1998 a dezembro de 1999, em 18 locais em três enseadas (Ubatumirim, Ubatuba e Mar Virado), utilizando um barco de pesca comercial. Em cada área de amostragem foram registrados a temperatura de fundo, salinidade e teor de matéria orgânica. Um total de 1.911 indivíduos foram coletados: 350 machos adultos, 475 fêmeas adultas não ovígeras, 584 fêmeas adultas ovígeras e 502 jovens. As fêmeas reprodutivas foram mais abundantes em áreas profundas; essa migração pode ser uma estratégia para melhorar a dispersão e a sobrevivência das larvas. As fêmeas ovígeras foram encontradas durante todo o ano, indicando uma reprodução contínua, com sua abundância positivamente correlacionada à temperatura. Durante a pesquisa de dois anos, foram encontrados caranguejos em todos os estágios de desenvolvimento gonadal. Podemos inferir que a região de Ubatuba fornece recursos adequados para o estabelecimento e desenvolvimento de A. spinimanus.

ABSTRACT This study describes the reproductive and recruitment patterns of the swimming crab Achelous spinimanus (Latreille, 1819) in the Ubatuba region of the northern coast of São Paulo, Brazil. Crabs were captured monthly from January 1998 to December 1999 in 18 sites located in three bays (Ubatumirim, Ubatuba, and Mar Virado), using a commercial fishing boat. In each sampling area, bottom temperature, salinity, and organic matter content were recorded. A total of 1,911 individuals were captured: 350 adult males, 475 non-ovigerous adult females, 584 adult ovigerous females, and 502 immature individuals. Reproductive females were more abundant in deeper areas; this migration might be a strategy to improve larval dispersion and survival. Ovigerous females were found year-round, indicating a continuous reproduction, and their abundance was positively correlated with temperature. During the 2-year survey, crabs with all gonadal development stages were found. We can infer that this region provides suitable resources for the development of A. spinimanus.

ABSTRACT Macrobrachium amazonicum is a commercially important freshwater prawn with a high degree of reproductive plasticity. The species is classified into two groups: coastal populations, with larger individuals exhibiting high fecundity and needing brackish water for larval development; and continental populations, with smaller specimens exhibiting low fecundities and completing metamorphosis in freshwater. The objective of this study was to investigate the influence of environmental factors in the fecundity, egg size and volume, and reproductive output in females of M. amazonicum from a continental population during a two-year period. We also compared our results with those obtained for other continental and coastal populations. Reproductive parameters differed markedly between continental and coastal populations in most cases. The continental population studied here, however, exhibited reproductive characteristics similar to those of coastal populations. The present study found a correlation between the reproductive parameters and the environmental variables analyzed. This result corroborates the hypothesis that wide variation in reproductive parameters in the geographical distribution of M. amazonicum is related to the environmental characteristics in which populations are inserted. We suggest that further studies could investigate the potential of continental populations for aquaculture, which could significantly reduce production costs.

ABSTRACT This is the first study to evaluate in broad spatiotemporal scales the growth parameters and population structure of Rimapenaeus constrictus, a barely damaged species composing the bycatch from shrimp fishing in the Western Atlantic. The abundance and size-class frequency distribution, growth, longevity and sex ratio were evaluated from monthly samples obtained in the northern littoral of São Paulo state from Jan/1998 to Jun/2003. We measured 5,812 individuals in which the sex ratio was skewed toward females; this was more evident in size classes greater than 10 mm in CL (carapace length) (binomial test, p<0.05). We selected 16 growth cohorts of females, and 8 of males, the majority consisting of younger individual cohorts excluded from the fisheries closure period. Growth estimates resulted in a CL∞ of 17.42 mm, a growth coefficient of 0.008 and a longevity of 579 days (1.60 year) for females, as well as a CL∞ of 16.3 mm, a growth coefficient of 0.01 and a longevity of 425 days (1.17 year) for males. Our results provide information of incontestable relevance to our knowledge of fishing management. We therefore strongly recommend that the fisheries closure period be changed to protect this species' recruitment period and consequently its adult individuals.

RESUMO O presente estudo investigou o crescimento, longevidade e dinâmica reprodutiva deArtemesia longinaris na costa sudeste do Brasil, durante um período de dois anos. Coletas mensais foram conduzidas em Ubatuba e Caraguatatuba, usando um barco de pesca de camarão equipado com redes "doublerig". Cada região foi dividida em sete estações amostrais com profundidades de até 35 m. Frequência de classes de tamanho, crescimento, longevidade, razão sexual e abundância de indivíduos em cada classe demográfica foram comparadas. A relação entre os fatores ambientais e a abundância de cada classe demográfica foi analisada utilizando a Análise de Correlação Canônica. Um total de 64.641 indivíduos foi coletado (6.928 analisados), com longevidades estimadas de 1,30 (Ubatuba) e 1,14 (Caraguatatuba) anos para fêmeas e 1,03 anos para os machos de ambas as regiões. Houve um desvio estatisticamente significativo na razão sexual a favor das fêmeas (teste Qui-quadrado, p < 0,05) em ambas as regiões. A Análise de Correlação Canônica resultou em um coeficiente de correlação canônica de 0,31 (p = 0,00002). A salinidade e a temperatura apresentaram alta correlação principalmente com a presença de fêmeas reprodutivas. Em geral, esta classe demográfica foi mais comum em condições de baixa temperatura e alta salinidade. Estes resultados, tal como outros obtidos em estudos abordando regiões de temperaturas mais frias com a espécie, encontram-se em conformidade com o padrão proposto pelo clássico paradigma do efeito latitudinal.

ABSTRACT The present study investigated the growth, longevity and reproductive dynamics ofArtemesia longinaris in the southeastern coast of Brazil over a two-year period. Monthly collections were conducted in Ubatuba and Caraguatatuba using a shrimp fishing boat equipped with "double-rig" nets. Each region was divided into 7 sampling stations up to 35 m deep. Size frequency distributions, growth, longevity, sex ratio, and abundance of individuals in each demographic class, were compared. The relationship between abiotic factors and abundance of each demographic class was assessed using a Canonical Correlation Analysis. A total of 64,641 individuals were collected (6,928 measured) with an estimated longevity of 1.30 (Ubatuba) and 1.14 (Caraguatatuba) years for females and 1.03 years for males in both regions. There was a statistically significant bias in sex ratio toward females (Chi-squared test, p < 0.05) in both regions. The Canonical Correlation Analysis resulted in a canonical correlation coefficient of 0.31 (p = 0.00002). Salinity and temperature showed high correlation mainly with the presence of reproductive females. In general, this demographic class was most common in conditions of low temperature and high salinity. These findings, as well as other studies carried out in colder regions with the same species, are consistent with classical latitudinal paradigm.

Upwelling events can occur in most of the oceans altering the water physical, chemical and sediment conditions and consequently the species communities dwelling the areas. For better understanding the behavior of populations inhabiting upwelling regions, the spatial and temporal distribution of a Penaeoidea shrimp was studied correlating it with the abiotic factors that vary during upwelling and non-upwelling periods in an area under influence of Cabo Frio upwelling. Bottom salinity and temperature, organic matter and sediment type from each station were sampled from March 2008 to February 2010, in six stations located between 5 and 45 m depth. The lowest temperatures were recorded during spring and summer for both years with temperature values lower than 19ºC. A total of 26,466 Artemesia longinaris shrimps were captured mainly in 10-35 m depth. Upwelling periods showed significant differences in abundance in relation to non-upwelling periods. The spatial distribution among stations varied according to the temperature with higher abundance in stations with values between 19 and 21ºC. The highest abundance of A. longinaris was recorded in spring and summer when intrusions of the cold waters of South Atlantic Central Waters (SACW) were frequent. Thus, the effect of cold water of SACW boosted by the upwelling was a determinant factor in the spatial and temporal distribution of A. longinaris in the studied region.

Los eventos de surgencia pueden ocurrir en la mayoría de los océanos alterando las condiciones físicas y químicas del agua y del sedimento, y por consiguiente a las comunidades de especies que viven en la zona. Para una mejor comprensión del comportamiento de las poblaciones que habitan en las regiones de surgencia, se estudió la distribución espacial y temporal de un camarón peneido y se correlacionó con los factores abióticos que varían durante los períodos de surgencia y sin surgencia, en una zona bajo la influencia de la surgencia de Cabo Frío. La salinidad y temperatura del fondo, materia orgánica y el tipo de sedimento de cada estación fueron muestreados entre marzo 2008 y febrero 2010, en seis estaciones ubicadas entre 5 y 45 m de profundidad. Las temperaturas más bajas se registraron durante primavera y verano para ambos años, cuando los valores de temperatura fueron inferiores a 19°C. Un total de 26.466 camarones de Artemesia longinaris se capturó principalmente entre 10 y 35 m. Los períodos de surgencia mostraron diferencias significativas en la abundancia en relación con los períodos sin surgencia. La distribución espacial entre estaciones varió según la temperatura con las mayores abundancias en las estaciones con valores entre 19 y 21°C. La mayor abundancia de A. longinaris se registró en primavera y verano, cuando las intrusiones de las frías aguas del Agua Central del Atlántico Sur (SACW) fueron frecuentes. Por lo tanto, el efecto del agua fría del SACW impulsada por la surgencia fue un factor determinante en la distribución espacial y temporal de A. longinaris en la región estudiada.

Este estudo investigou a importância dos fatores ambientais sobre os padrões de abundância dos decápodos na costa sudeste brasileira. Amostragens foram feitas mensalmente de janeiro-1998 a dezembro-1999 em Ubatumirim e Mar Virado, região de Ubatuba, usando um barco de pesca camaroneiro equipado com redes doublerig. Foram selecionadas seis áreas adjacentes aos costões rochosos. Amostras de água de fundo foram coletadas usando garrafa de Nansen, para mensurar a temperatura e salinidade. Amostras de sedimento foram obtidas utilizando pegador de Van Veen, para determinação da textura e conteúdo de matéria orgânica. A associação dos fatores ambientais com a abundância das espécies foi verificada através da Análise de Correspondência Canônica (α = 0,05). Quarenta e uma espécies de Decapoda foram utilizadas na análise multivariada. A análise indicou que a textura do sedimento (phi) e a temperatura foram os fatores mais fortemente correlacionados (p < 0,05) com a abundância espacial e temporal das espécies. Considerando a região de estudo como zona de transição faunística, incluindo espécies de origem tropical e subantártica, as espécies responderam diferentemente aos fatores ambientais, principalmente à temperatura. Possivelmente os decápodos ajustem sua distribuição de acordo com suas limitações fisiológicas intrínsecas, como resultado dos recursos disponíveis.

This study investigated the importance of variations in environmental factors affecting the abundance patterns of decapods on the southeastern Brazilian coast. Sampling was carried out monthly from January 1998 through December 1999 in Ubatumirim and Mar Virado, Ubatuba region, using a commercial shrimp fishing boat equipped with double-rig nets. Six areas adjacent to rocky shores were chosen. Bottom-water samples were collected using a Nansen bottle, to measure the temperature and salinity. Sediment samples were also obtained by means of a Van Veen grab, for determination of texture and organic-matter content. The association of environmental factors with species abundance was evaluated by Canonical Correspondence Analysis (α = 0.05). Forty-one species of Decapoda were used in the multivariate analysis. The analysis indicated that sediment texture (phi) and bottom temperature were the main factors correlated (p < 0.05) with the spatial and temporal abundance of the species. Considering the study region as faunal transition zone, including a mixture of species of both tropical and subantarctic origin, the species responded differently to environmental factors, mainly temperature. It is conceivable that the decapods adjust their distribution according to their intrinsic physiological limitations, possibly as a result of the available resources.

A biologia populacional de Exhippolysmata oplophoroides (Holthuis, 1948) foi estudada na enseada de Ubatuba (23º26'S, 45º02'W), Ubatuba, São Paulo, Brasil, de setembro de 1995 até agosto de 1996. Cada amostragem compreendeu oito transectos (14000 m² cada), amostrados mensalmente com três repetições. Os espécimes foram classificados quanto à presença ou ausência de ovos nos apêndices abdominais. Os camarões espinhos ocorreram somente em seis transectos, sendo mais abundantes no transecto II, com a maior incidência no final da primavera e ao longo dos meses de verão. Indivíduos ovígeros e não ovígeros estiveram presentes o ano todo, numa proporção semelhante a 1:1. O transecto II é caracterizado por altos valores de salinidade e oxigênio, temperatura entre 26 e 29º C, baixo teor de matéria orgânica e sedimento composto por areia muito fina. Tais características biológicas e ambientais permitem o estabelecimento e a manutenção da população de E. oplophoroides na região de estudo.

The population biology of Exhippolysmata oplophoroides (Holthuis, 1948) was studied in Ubatuba Bay (23º26'S, 45º02'W), Ubatuba, São Paulo, Brazil, from September/1995 to August/1996. Each sampling comprised eight transects (14 000 m² each), sampled monthly with three repetitions. The specimens were classified with respect to the presence or absence of eggs in the abdominal appendages. Spine-shrimps occurred only on six transects, being most abundant on transect II, with the highest incidence in late spring and throughout the summer months. Ovigerous and non-ovigerous shrimps were present year-round, in an approximately similar proportion (1:1). Site II in Ubatuba Bay is characterized by high salinity and oxygen values, temperature between 26 and 29ºC, low organic matter content in the sediment, and a bottom composed of very fine sand; these environment and biological features allow the establishment and maintenance of the population of E. oplophoroides.