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Paulo, BraziL Emailfransozo@ibb.IlI.U) Yp.br ABSTRACTThe influence of environmental factors on the abundance and spatial-tempotal distribution of the sltrimp Xiphopenaeus kroyeri was investigated. in southeastern Brazil over 2 years. Monthly collections were conducted in Mar Vrrado, Dbatuba and Dbatumi!im Bays using a commercial shrimp fishing boat equipped with 2 "doubJe.-rig" nets. Each bay was divided into 6 samplJng stations, all of which were less than 25 m deep. The spatial distribution of X kroyeri differed among Bays. Highest abundance values were recorded in areas where silt and clay comprised more than 70% of the bottom sediment Abundance of X kroyeri followed a seasonal trend, heing higher during fall and winter, when intrusions of tropical waters are frequent, causing an increase in salinity (> 35%") and temperature (> 21° C). A clear decrease in shrimp abundance followed a decrease in bottom temperature « 20" C) during spring and summer due to the influence of cold water currents, particularly the South Atlantic Central Water. These results suggest that sediment type, salinity, and temperature are among the most important variables affeclJng the spatial and seasonal distribution of this species.

The in£uence of several environmental factors on the abundance and spatial^temporal distribution of the shrimp Artemesia longinaris were investigated from January 1998 to December 1999 in the Ubatuba region of Sa‹ o Paulo State, Brazil. Collections were performed monthly in the bays of Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV). Six sampling transects were established in each bay, four were parallel to the shore line, and two were next to the rocky shores. A commercial shrimp ¢shing boat equipped with two 'double-rig' nets was used. A total of 11,503 individuals was collected, including 1633 from UBM, 6344 from UBA and 3526 from MV. The majority of the captured specimens came from the deeper areas (15 to 20 m) with high salinity (34 to 36 ppt). The highest abundance of A. longinaris in Ubatuba bay was recorded in areas where ¢ne and very ¢ne sand comprised more than 70% of the sediment. Moreover, the abundance of A. longinaris followed a seasonal trend, being higher during the summer, when intrusions of cold South Atlantic Coastal Waters (SACW) are frequent. Thus, type of sediment, temperature and salinity are determinant factors in the distribution of A. longinaris in the studied region.

The objective of the present study is to characterize the physical and chemical environmental parameters of Ubatuba Bay (SP), as a subsidy for studies of the composition and distribution of benthic crustaceans which live on the non-consolidated sublittoral bottom of this area. Depth, temperature, salinity, dissolved oxygen, organic content and granulometric composition of the sediments were measured monthly from September/95 to August/96 in eight subareas of the bay. The bay presents an average depth of 9.3 m and is characterized by the following annual mean values for the hydrologic factors: temperature 23.8 o C, salinity 33.2‰ and dissolved oxygen 5.11 mg/l. The annual mean for the organic matter content of the bay bottom sediments was 11.8% and most subareas presented a grain size composition dominated by pelitic sediments. These peculiar abiotic characteristics are very important for the reproduction and development principally of brachyuran and anomuran crabs, and shrimps which have a close relationship with those substrates.Key words: Crustacea, environmental factors, sediment, organic content, Ubatuba, Brazil. RESUMO Caracterização dos parâmetros físicos e químicos da Enseada de Ubatuba, litoral norte de São Paulo, BrasilO presente trabalho objetivou a caracterização de alguns parâmetros físicos e químicos da Enseada de Ubatuba (SP), como subsídio para estudos sobre composição e distribuição de invertebrados bentônicos associados ao substrato não-consolidado desta área, além de servir para comparações com cenários futuros da região. Foram estabelecidas oito subáreas para a amostragem dos parâmetros ambientais (profundidade, temperatura, salinidade e teor de oxigênio dissolvido na água, teor de matéria orgânica e granulometria do sedimento de fundo). Em todas a subáreas as coletas foram efetuadas mensalmente, durante três dias consecutivos, de setembro de 1995 a agosto de 1996. As amostras de água foram coletadas com uma Garrafa de Nansen e o sedimento de fundo com um pegador do tipo Van Veen (1/40 m 2 ). Os valores médios dos parâmetros encontrados na Enseada foram: profundidade (9,3 ± 3,66 m), temperatura (23,8 ± 0,62 o C), teor de oxigênio dissolvido (5,11 ± 0,29 mg/l), salinidade (33,2 ± 0,35‰) e teor de matéria orgânica (11,8 ± 5,35%). Quanto à granulometria, houve predomínio das areia fina e muito fina. Entre as subáreas, pode-se constatar diferenças significativas na profundidade, no teor de oxigênio dissolvido, no teor de matéria orgânica e na granulometria do sedimento. Os valores encontrados permite-nos caracterizá-la como uma enseada com um padrão semelhante às adjacentes, mas com parâmetros hidrológicos e sedimentológicos fortemente estabe-

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Arenaeus cribrarius is a mainly tropical crab that occurs in the Western Atlantic Ocean, Brazil being its type-locality. The species ranges from Vineyard Sound, Massachusetts, USA to La Paloma, Uruguay. Information about this species is scarce. The relative growth ofA. cribrarius was analyzed, based on some morphometric relations, where the carapace width, excluding lateral spines (CW), was used as an independent variable. A total of 403 specimens (189 males and 214 females), was collected in Ubatuba, State of São Paulo, Brazil, with otter-trawls. The animals were sexed and sorted to maturation phase (juvenile or adult). Some measurements were made: carapace (length and width excluding lateral spines), abdomen (greatest width of the fifth somite in females and the sixth in males) and major chela (greatest length, width and height, dactylus length). This study was made by the application of the power function (y=a.xb) which was fitted to the data and the pattern of growth established for each parameter by the "b"-value (constant of allometry), as positive allomctry (b>1), negative allometry (b<1) or isometry (b=1). The morphometric relations of the carapace showed a tendency to isometry. In females, the abdominal width grew in positive allometry, higher in juveniles (b= 1.33) than in adults (b=1.18). In this case, an overlap and discontinuity was noticed between the phases over a carapace width range of 55 to 70 mm, where the puberty molt occurs. The majority of relationships showed that the major chela of the males grew in positive allometry, however, the greatest allometric difference between the phases was observed towards the propodus length with 1.09 as juvenile and 1.26 as adult "b"values. In the males, this variable showed an inflection between the CW range of 45 to 55 mm, where the transition to the maturation phase occurs. The relative growth of this species is similar to those of previously studied species. This indicates, that the propodus length and the abdominal width are the morphometric variables most appropriate to estimate the size at the beginning of the sexual maturity for males and females of this species, respectively.

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