Abstract The aim of this study was to investigate the spatial and temporal distribution of Exhippolysmata oplophoroides and relate its abundance to various environmental variables (bottom water temperature and salinity, texture of sediment and percentage of dissolved organic matter). The sampling of shrimp and abiotic factors was carried out monthly from July 2012 to June 2014, in seven trawling stations (S1-S7), four of them in the marine area and three in the estuary (southern coast of the state of São Paulo, Brazil). The distribution of individuals showed significant differences between stations and between the two years of study (ANOVA, p < 0.05), but not among seasons (p > 0.05). A total of 2005 shrimp were collected, with the highest abundance being found in S4 (n= 937). Bottom salinity and sediment texture were the environmental factors with significant influence on the distribution of the species in the studied region. The low salinity values at S6 and S7, and the low capacity for osmoregulation of E. oplophoroides limit its distribution in the marine environment. High concentrations of silt+clay found at S4 contributed to the accumulation of organic matter, which influenced the high abundance of shrimp there. The information gathered in our study provides valuable results for the knowledge of this species in its area of distribution and contributes to a better understanding of the life history.

ABSTRACT This study investigated the population dynamics of Persephona punctata with emphasis on population structure, sex-ratio, spatial distribution, maturity and reproductive period. Crabs and environmental factors (i.e., water temperature and salinity, and sediment texture and organic matter content) were collected monthly, from July 2012 to June 2014 in four sites within the Federal Environmental Protection Area of Cananéia-Iguape-Peruíbe: located in the oceanic area adjacent to the Cananéia region. The population had a female-biased sex-ratio. Persephona punctata had a seasonal reproduction and the higher percentage of ovigerous females (OF) occurred in spring and summer. There was a positive correlation (“lag 0”) between temperature and number of OF (cross-correlation, p < 0.05) and a negative correlation between salinity and OF (“lag-2”), suggesting that periods of higher salinity may be favorable to larval hatching. The estimated size (carapace width - CW50) at the onset of gonadal maturity of males (35.0 mm) was larger than that of females (30.1 mm), which is a common feature of Brachyura. Our results extend the knowledge on the life history of P. punctata and may be useful for the development of future mitigation measures aimed at its conservation.

Resumo: Os caranguejos Persephona são intensamente capturados na pesca do camarão como fauna acompanhante, inclusive na região de Cananéia no litoral do estado de São Paulo, no Brasil. A avaliação da distribuição espaço-temporal pode, consequentemente, fornecer informações sobre variações na abundância de Persephona punctata e Persephona mediterranea, bem como as variáveis ambientais que afetam suas distribuições e uma possível partilha de habitat desses congêneres. Com um barco de pesca de camarão equipado com redes de arrasto duplo, os indivíduos foram coletados mensalmente de julho de 2012 a junho de 2014 em sete locais: quatro na área costeira adjacente à região de Cananéia e três na área estuarina Mar Pequeno. A abundância dessas espécies foi comparada de acordo com a distribuição espacial (entre sítios) bem como entre anos e estações. Um total de 396 indivíduos de P. punctata e de 64 de P. mediterranea foram capturados. A abundância de ambas as espécies foi maior no segundo ano de coleta (julho de 2013 a junho de 2014). A abundância de ambas as espécies foi maior na área costeira, e apenas um indivíduo de cada espécie foi capturado na área estuarina devido à baixa salinidade neste local (27.7‰ aproximadamente). A temperatura foi o fator ambiental que afetou significativamente a distribuição das espécies, com maiores abundâncias em períodos mais quentes. A variação temporal da abundância foi modulada pela temperatura, enquanto a salinidade modulou a distribuição espacial de P. punctata e P. mediterranea. Em Cananéia as espécies não apresentaram diferenças na distribuição espaço-temporal, o que nos permite assumir elas habitam a área de uma forma muito similar.

Abstract: Crabs of the genus Persephona are intensely captured in shrimp fisheries as bycatch in the Cananéia region off the coast of the state of São Paulo, Brazil. The analysis of the spatial and temporal distribution of Persephona punctata and Persephona mediterranea could provide information about variation in the abundance of these species, as well as the environmental variables affecting their distribution and the existence of a possible habitat partitioning. Using a shrimp fishery boat equipped with double-rig nets, crabs were monthly captured from July 2012 to June 2014 in seven sites: four in the coastal area adjacent to the Cananéia region and three in the Mar Pequeno estuarine area. The abundances of both species were compared according to spatial (among sites) and temporal (years and seasons) scale distribution. A total of 396 individuals of P. punctata and 64 of P. mediterranea were captured. The abundance of both species was higher in the second sampling year (July 2013-June 2014) and in coastal areas; only one individual of each species was captured in the estuarine area due to the low salinity at this location (approximately 27.7‰). The temperature was the environmental variable that most affected the distribution of both species, which was more abundant in warmer periods. The temporal variation in abundance was modulated by temperature, while salinity modulated the spatial distribution of P. punctata and P. mediterranea. The spatial-temporal distribution of both species differered in Cananéia, pointing to a similar use of the environment's resources.

Regions affected by upwelling show environmental characteristics that may change the distribution of the species. This study evaluated the influence of environmental factors on the spatiotemporal distribution of two caridean shrimps, Nematopalaemon schmitti and Exhippolysmata oplophoroides, in a region of the Brazilian coast affected by Cabo Frio upwelling. Shrimps were collected monthly from July 2010 through June 2011 off Macaé off the northern coast of Rio de Janeiro State, at six locations: three at 5 m, and the other three at 15 m depth. Shrimp abundance was compared among seasons and sampling sites. Nematopalaemon schmitti (n = 1200) was more abundant at 5 m depth while E. oplophoroides (n = 2176) occurred predominately at 15 m. There were significant seasonal fluctuations in the distribution of the species in the region, resulting from variation in bottom temperature. The presence of the South Atlantic Central Water (SACW) favors the decrease in the abundance of N. schmitti and highest abundance of E. oplophoroides. The abundance of E. oplophoroides and the percentage of organic matter were significantly and positively correlated. The organic matter content in the sediment and water temperature was among the most important variables affecting seasonal distribution of the species. The distinct environmental characteristic between the bathymetric regions were a determinant factor in their spatial distribution.

Abstract This study describes the weight vs. carapace length relationship and provides the total and monthly condition factor values for populations of Macrobrachium jelskii (Miers, 1977) and M. brasiliense (Heller, 1868) occurring in southeastern Brazil. The biological characteristics were compared and related to the climatic environmental factors between the two areas. Our investigation sampled M. jelskii from the Barra Mansa Dam, Mendonça, SP, a semilotic environment with greater resilience than the Talhadinho Stream, Talhado, SP, a lotic environment where specimens of M. brasiliense were captured. Individuals were classified according to sex and measured at the carapace length (CL) and weighed (WE). The relationship WE/CL was analyzed by dispersion diagrams of the empirical points, which were set to the power function (WE = a.CL b ). Values of the mean condition factor were compared monthly. In total, 1493 individuals of M. jelskii and 843 individuals of M. brasiliense were captured. Analyses of the constant allometry revealed that both sexes of M. jelskii, as well as females of M. brasiliense grow proportionately more in size than weight. The results concerning the morphometric aspects studied in both species suggest an association with the reproductive processes.