Abstract Rimapenaeus constrictus is a penaeid shrimp widely distributed in the Western Atlantic, frequently captured as bycatch in trawling activities. Here we describe the weight vs. carapace length relationship and the condition factor of the species. Shrimps were sampled in the Ubatuba region, northern littoral of São Paulo State, monthly. We analyzed 4,952 individuals (1,371 males and 3,581 females). We measured the individuals’ weight and carapace length, and the condition factor (CF) was calculated for both sexes. Females had a heavier body when compared to males, probably due to their greater maximum body size achieved. Both sexes presented a negative allometric growth in weight, probably due to their reproductive pattern and activities. We found similar mean CF values for males and females. From temporal analysis, the highest CF values for females were observed during the seasons with lower water temperatures. Such a situation may happen because females’ CF tend to be influenced by a greater food availability in the environment, induced by the intrusion of the South Atlantic Central Water during the spring and early summer in the Ubatuba. The information presented here could be used as subside in protection actions and management of bycatch species.

Abstract We aimed to analyze the crustacean bycatch from the Xiphopenaeus kroyeri fishery in the Santa Catarina State and compare the bycatch’s biomass to that of the target species. Shrimp and environmental factors were sampled monthly from July 2010 through June 2011. For each crustacean species, we calculated the number of individuals, the relative abundance and the occurrence frequency. The relative abundance was classified as very abundant (Va), abundant (Ab) or low abundance (La), while the occurrence frequency was labeled continuous (Co), accessory (Ac) or accidental (Ad). We observed a total richness of 28 species, which is considered high for a subtropical region. Brachyura was the most frequent taxon (74%) followed by Penaeiodea (18%). Five species were considered Va (Arenaeus cribrarius, Callinectes danae, C. ornatus, Isochelis sawayai and Pleoticus muelleri), and eight species were considered Co (A. cribrarius, C. danae, C. ornatus, Farfantepenaeus paulensis, Hepatus pudibundus, Libinia spinosa, Litopenaeus schmitti and Sicyonia dorsalis), suggesting that the studied environment is heterogeneous and provides a variety of microhabitats, enabling many species to coexist. Therefore, the high species richness observed demonstrates the ecological importance of this region and thus the necessity of strategies aiming to minimize the impacts caused by trawling fisheries.

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.