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Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate; C12H15NO3) is one of the most toxic carbamate pesticides. For acute toxicity of carbofuran, juveniles of Macrobrachium olfersii were exposed to different concentrations of carbofuran using the static renewal method at different temperature levels (15, 20 and 25°C) at pH 7.0. The main purpose of the present study was to detect the acute toxicity of carbofuran to M. olfersii and investigate its effects on oxygen consumption and ammonium excretion; these tests have not been carried out in this species before. First, the acute toxicity - median lethal concentration - of carbofuran to M. olfersii for 24, 48, 72 and 96 h was examined, which resulted in the following values: 1.64, 1.22, 0.86 and 0.42 mg L(-1), respectively. Furthermore, we also found that carbofuran caused an inhibition in oxygen consumption of 60.6, 65.3 and 66.2% with respect to the control. In addition, after separate exposures to carbofuran, elevations in ammonium excretion were more than 500% with respect to the control.

Fishing tourism is growing steadily in Brazil. Artisanal fishers meeting the demand for recreational fishing are capturing live juvenile shrimp in the estuaries and selling them for live bait, preventing the recruitment of a larger contingent into the ocean. This study compares the efficiency of using lambari, Deuterodon iguape Eigenmann, as live bait with the shrimp, Penaeus schmitti Burkenroad, while fishing for common snook (Centropomus spp.), as well as to evaluate the swimming behaviour of D. iguape in different salinities. The results showed that there was no significant difference between the live baits used (P. schmitti vs D. iguape). The month, the period of the day and salinity presented differences. The size of the species did not depend on the type of bait used. There was no statistical difference in swimming behaviour, but there was a trend of increased speed and displacement in the group exposed to a salinity of 10 g/L. In conclusion, D. iguape appears as effective as P. schmitti and can be successfully used as live bait; and from an ecological point of view, it reduces the impact of fishing on juvenile shrimp.

Juvenile cobia (Rachycentron canadum) (total length 15.16 ± 0.92 cm and weight 19.26 ± 4.5 g) were exposed to different concentrations of ammonia-N (unionized plus ionized ammonia as nitrogen), using the static renewal method at different salinity levels of 5, 20, and 35% at pH 8.1 and 25°C. The 24, 48, 72, 96 h LC 50 values of ammonia-N for R. canadum juveniles were 60.mg l -1 at 5%, respectively. The 24, 48, 72, 96 h LC 50 values of NH 3 -N (unionized ammonia as nitrogen) were 1.81, 1.46, 1.12, and 0.68 mg l -1 at 35%; 1.75, 1.49, 0.96, and 0.65 mg l -1 at 20%; and 1.52, 0.97, 0.71, and 0.31 mg l -1 at 5%, respectively. As the salinity decreased from 35 to 5%, susceptibility of ammonia-N increased by 34.5, 47.88, 50.56, and 64.23% after 24, 48, 72, and 96 h exposure, respectively. Furthermore, we found that exposure of fish to ammonia-N caused an increase in oxygen consumption of 129.1, 157.5, and 192% and a decrease in the ammonia excretion level of 53.4, 38.2, and 23.3% with respect to the control.

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The effect of heavy metal in fish has been the focus of extensive research for many years. However, the combined effect of heavy metals and nanomaterials is still a new subject that needs to be studied. The aim of this study was to examine histopathologic alterations in the gills of Nile tilapia (Oreochromis niloticus) to determine possible effects of lead (Pb), carbon nanotubes, and Pb+carbon nanotubes on their histological integrity, and if this biological system can be used as a tool for evaluating water quality in monitoring programs. For this, tilapia were exposed to Pb, carbon nanotubes and Pb+carbon nanotubes for 4 days. The main alterations observed were epithelial structure, hyperplasia and displacement of epithelial cells, and alterations of the structure and occurrence of aneurysms in the secondary lamella. The most severe alterations were related to the Pb+carbon nanotubes. We conclude that the oxidized multi-walled carbon nanotubes enhanced the acute lead toxicity in Nile tilapias. This work draws attention to the implications of carbon nanomaterials released in the aquatic environment and their interaction with classical pollutants.

A pesca de Cananéia tem o camarão-sete-barbas como principal produto desembarcado. O trabalho foi desenvolvido no litoral sul do Estado de São Paulo, no período de 1998 e 1999, coletando dados de produção, esforço e valor econômico do camarão-sete-barbas. A produção média desembarcada de camarão-sete-barbas no município de Cananéia, nos anos estudados foi de 728 toneladas anuais. As categorias de comércio estão divididas entre camarão-sete-barbas bruto (sem seleção a bordo), camarão-sete-barbas escolhido (com seleção), camarão-setebarbas descabeçado (com seleção e posterior processamento) e camarão-sete-barbas miúdo (com seleção, sendo retirado os maiores). Os maiores desembarques ocorreram no primeiro semestre e o segundo semestre se caracterizou pela maior produção de camarão escolhido. Os resultados mostraram que as capturas de camarão-sete-barbas estão em declínio, sugerindo pouca eficiência da portaria que estabelece o defeso da espécie para a conservação do recurso. A análise da composição da rejeição junto à pesca artesanal é necessária, com o intuito de melhorar a administração pesqueira e o aproveitamento racional das capturas. Palavras chave: Pesca, camarão, Brasil THE FISHING OF BOB SHRIMP Xiphopenaeus kroyeri IN CANANÉIA DISTRICT (SP) -BETWEEN 1998 AND 1999 ABSTRACTThe fishery of Cananéia (São Paulo, Brazil) is dominated by catches of the sea bob shrimp Xiphopenaeus kroyeri. The work was developed in the southern coast of São Paulo State, between 1998 and 1999 and included collecting production, capture effort and economic value data of the Xiphopenaeus kroyeri. Mean landings of shrimp in the municipal district of Cananéia have been approximately 728 tons/year. The trade categories are divided into gross shrimp (without selection on board), chosen shrimp (with selection), clean shrimp (with selection and posterior processing) and small shrimp (after selection of larger ones). Largest landings occurred in the first semester and the second semester was characterized by the largest production of chosen shrimp. The results suggest presented that the fishery is declining, and do not agree with the current period of closure. The analysis of the by-catch composition of artesanal fishery is necessary, in order to improve the fishing administration and the rational use of the resource.