Size at maturity and egg capsules of the softnose skates Bathyraja brachyurops (Fowler, 1910) and Bathyraja macloviana (Norman, 1937) (Elasmobranchii: Rajidae) in the SW Atlantic (37 degrees 00'-39 degrees 30'S)

P>The softnose skates Bathyraja brachyurops and Bathyraja macloviana represent an important portion of the skate catches of the Uruguayan trawling fleet in the southwestern Atlantic. From March to October 2004, specimens of these species were collected at 75-200 m depth range in the area situated between latitudes 37 degrees 00'-39 degrees 30'S. For B. brachyurops, total length at which 50% of the specimens were retained by the gear was 68.0 cm for both sexes; T(L50) was estimated at 65.4 cm for males and 67.0 cm for females. For B. macloviana, total length at which 50% of the specimens were retained was 56.0-57.0 cm for both sexes; T(L50) was estimated at 53.5 cm for males and 52.0 cm for females. Egg capsule length varied from 79-91 mm in B. brachyurops and 69-75.5 mm in B. macloviana. In both species, capsules displayed striated surfaces and similar gross morphology, although egg capsules of B. macloviana had more robust anterior horns and a smaller size than those of B. brachyurops. Egg capsules of the latter also exhibited microscopical prickles. Capsule edges were laterally keeled with a groove along the keel, and a straight and transverse velum was present in the egg capsules of both species.

Influência do dossel na atividade de morcegos (Chiroptera: Phyllostomidae) em três fragmentos no estado de São Paulo

The moonlight's influence on bats activity patterns have been documented for some species. Usually, bats react to increased illumination by reducing the use of open spaces or restricting foraging activity. This study aimed to test lunar cycle influence on frequency of Phyllostomidae bats in three fragments, located in northwestern São Paulo State, analyze the capture rate in the different phases of the cycle and correlate the results with canopy structure of each remaining. This study was based on the on the assumption that the influence of light on the behavior of bats is lower in shaded areas. The decrease in species richness in relation to the moon phase was significant in the least shaded area. In environments with more closed canopy, the rate of capture of bats was homogeneous along the four phases of the moon. The results indicated that local wealth cannot be sampled effectively if the catches are restricted to any period of the lunar cycle for fruit and nectar, and in more shaded environments the effects of lunar phobia is apparently null.

Angling sport fishing in Lobo-Broa reservoir (Itirapina, SP, Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Artisanal fisheries in a Brazilian hypereutrophic reservoir: Barra Bonita reservoir, middle Tietê river

Esse estudo avaliou aspectos quantitativos qualitativos do desembarque pesqueiro no reservatório hipertrófico de Barra Bonita. Os dados foram coletados mensalmente (julho/2004-junho/2006) em três localidades e informações sobre captura, esforço de pesca e técnicas de pesca foram registrados de 745 desembarques, totalizando 86.691,9 kg de pescado capturados. As espécies mais capturadas foram as exóticas tilápias, especialmente a tilápia-do-nilo (Oreochromis niloticus L.), que representaram 82,5% da biomassa total. A produtividade pesqueira do reservatório foi de 11,1 kg/ha-1/dia-1 com uma Captura Por Unidade de Esforço de 62,4 kg/pescador-1/dia-1 . Cinco técnicas de pesca foram identificadas: tarrafas, rede de espera, rede de arrasto, pesca da batida e pesca da batida + rede de espera. Análise de DCA relacionou as estratégias ativas com a captura de tilápia, as estratégias passivas com a captura de Pimelodus maculatus (Lacepède) e Triporthues angulatus (Spix & Agassiz) e a estratégia mista com a captura de tilápia, cascudos e Prochilodus lineatus (Valenciennes). Os resultados da ANCOVA foram significativos para todas as variáveis analisadas (época, local de pesca e técnicas de pesca). Os resultados mostram uma substituição da pesca da corvina, Plagioscion squamossisimus (Heckel) na década de 1990, pela tilápia-do-nilo. A substituição pode ter sido provocada pelo aumento da eutrofização do reservatório, aliado à mudança das estratégias de pesca. A pesca no reservatório de Barra Bonita seguiu padrões de outros reservatórios eutrofizados brasileiros, com a pesca sustentada pela exótica tilápia-do-nilo.

Fishing resources in the rio Cuiabá basin, Pantanal do Mato Grosso, Brazil

O recurso pesqueiro da bacia do rio Cuiabá, um dos mais importantes tributários da bacia do Alto Paraguai, formadora do Pantanal, foi estudado a partir dos dados de desembarque de pescado obtidos no Mercado do Porto de Cuiabá, Mato Grosso, Brasil. São descritas a composição e procedência das capturas para os anos de 2000 e 2001. O rio Cuiabá é a fonte dominante de pescado para a cidade de Cuiabá, mas uma parte do pescado comercializado localmente é oriunda do rio Paraguai. Além disso, atualmente o pescado vem de regiões mais distantes da zona urbana. Constatou-se que a pesca incide basicamente sobre espécies migradoras. As principais espécies capturadas foram os pimelodídeos pintado -Pseudoplatystoma corruscans, cachara -Pseudoplatystoma fasciatum e jaú -Paulicea luetkeni e os caraciformes pacu -Piaractus mesopotamicus, piraputanga -Brycon microlepis, piavuçu -Leporinus macrocephalus e dourado -Salminus brasiliensis. Os grandes bagres (Pimelodidae) foram os responsáveis por 70% do pescado desembarcado no período de estudo, dentre os quais o pintado foi a espécie mais capturada. Os dados indicam que as capturas atuais estão bem aquém daquelas registradas no início da década de 80. Além disso, apesar do número e composição de espécies capturadas serem similares àqueles da década de 80, a distribuição da abundância mudou. Atualmente a pesca captura mais espécies carnívoras do que espécies de níveis tróficos inferiores. Estes achados não podem ser creditados somente a sobrepesca, mas parecem resultar de uma complexa interação entre degradação ambiental, mudanças na preferência de mercado e medidas legais restritivas à pesca.

Flutuação populacional de adultos de Anastrepha fraterculus (Wied.) em cultivo protegido e convencional de videira

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pampean lizard assemblage from subtropical Brazil: a temporal analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bats from Fazenda Intervales, Southeastern Brazil: species account and comparison between different sampling methods

Assessing the composition of an area's bat fauna is typically accomplished by using captures or by monitoring echolocation calls with bat detectors. The two methods may not provide the same data regarding species composition. Mist nets and harp traps may be biased towards sampling low flying species, and bat detectors biased towards detecting high intensity echolocators. A comparison of the bat fauna of Fazenda Intervales, southeastern Brazil, as revealed by mist nets and harp trap captures, checking roosts and by monitoring echolocation calls of flying bats illustrates this point. A total of 17 species of bats was sampled. Fourteen bat species were captured and the echolocation calls of 12 species were recorded, three of them not revealed by mist nets or harp traps. The different sampling methods provided different pictures of the bat fauna. Phyllostomid bats dominated the catches in mist nets, but in the field their echolocation calls were never detected. No single sampling approach provided a complete assessment of the bat fauna in the study area. In general, bats producing low intensity echolocation calls, such as phyllostomids, are more easily assessed by netting, and bats producing high intensity echolocation calls are better surveyed by bat detectors. The results demonstrate that a combined and varied approach to sampling is required for a complete assessment of the bat fauna of an area.

Fisheries and fishing effort at the Indigenous Reserves Ashaninka/Kaxinawá, river Breu, Brazil/Peru

Este artigo tem o objetivo de descrever a pesca de subsistência das populações tradicionais de uma aldeia Ashaninka e duas Kaxinawá vivendo à beira do rio Breu. Inicialmente, foram treinados monitores para preencher fichas de coleta de dados das pescarias nas aldeias durante um ciclo anual (agosto/1995 agosto/1996). A partir desses dados realizaram-se os inventários das espécies de peixes capturadas e dos ambientes pesqueiros. A análise dos dados foi efetuada por meio de estatística descritiva e exploratória. Os resultados obtidos foram os seguintes: i) os ambientes mais procurados pelos índios foram os poços; ii) as espécies mais capturadas os mandis (35%, Pimelodidae), os bodes ou cascudos (Loricariidae), com destaque para o bode praiano (25%, Hypostomus sp.), o curimatã (9%, Prochilodus sp.) e os saburus (8%, Curimatidae), entre outros; iii) constatou-se que os arreios ou apetrechos de pesca que mais capturam peixes são o tingui (veneno), a tarrafa e o arco/flecha, respectivamente; iv) durante o verão a atividade de pesca é mais intensa; v) as medidas de esforço de pesca e os fatores associados que foram estatisticamente significativos nas predições das capturas na Reserva Indígena foram: f1 = o (número de pescadores), f2 = o (número de pescadores*tempo total das pescarias) e f3 = o [(número de pescadores*tempo total das pescarias)-(o tempo de deslocamento)] e os fatores aldeias e arreios; vi) apesar da maioria das pescarias serem realizadas a pé até os pesqueiros, as capturas são maiores quando a locomoção se dá através de canoa a remo; e vii) os pescadores mais ativos nas pescarias na Reserva Indígena foram os Kaxinawá.

Biogeography of common dolphins (genus Delphinus) in the Southwestern Atlantic Ocean

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Amazon fisheries. I. - Variations in the relative abundance of tambaqui ( Colossoma macropomum Cuvier, 1818) based on catch and effort data of the gill-net fisheries.

Adjusted mean catches which are calculated discounting the effect of average fishing effort increase the further the lake is from Manaus, Brazil. -from Author

Comparing river basins world-wide and contrasting inland fisheries in Africa and Central Amazonia

An analysis of covariance relating basin area (A, km2) to river length (L, km) and discharge rate (D, m3 s-1) was performed for two continents and showed that the two covariates (L and D) were highly significant and that the strength of the relationship changed between continents. For comparison, D was excluded but the result remained the same. Although geomorphological models are useful for establishing global levels of production, these regressions should be applied with caution. Historically, simple statistical models were developed to predict fish catches in rivers. These, based upon regression of catches on channel length or basin area for Africa and Central Amazonia, are contrasted in this paper because of their generally similar approach.

Artificial reefs and their effects on fish assemblages in a Brazilian reservoir and Tailrace

In this paper, we evaluate the effects of artificial reefs on fish assemblages in a hypereutrophic reservoir and in the lotic zone immediately below dam. Fish diversity was highest in the lotic zone relative to the reservoir. We also found an inverse relationship between diversity and distance from the river margin. Catches near the artificial reefs were more diverse than in control areas. A seasonal effect, possibly caused by variation in temperature, was significant in all comparisons. We argue that, in a scale of local effects, the ecological function of these structures would be similar to refuges.

O impacto da pesca do camarão-rosa Farfantepenaeus paulensis (Perez-Farfante) (Decapoda, Penaeidae) nas assembléias de peixes e siris do Parque Nacional da Lagoa do Peixe, Rio Grande do Sul, Brasil

This work evaluates the impact of the pink shrimp Farfantepenaeus paulensis (Perez-Farfante, 1967) fishery on fish and crab assemblages of Lagoa do Peixe National Park, Brazil. We observed that composition of catches is similar to shrimp fisheries using fyke-net at others estuaries of Rio Grande do Sul State: pink shrimp (53%), accessory catches (24%) and bycatch (23%). However, fishery composition showed distinct differences along the saline gradient of the main park's lagoon. Regarding only fish species, the most impacted species in this fishery were Brevoortia pectinata (Jenyns, 1842), Micropogonias furnieri (Desmarest, 1823), and Jenynsia multidentata (Jenyns, 1842). In others estuaries from Rio Grande do Sul, in contrast, the most impacted species were M. furnieri, Genidens barbus (Lacepède, 1803) and Genidens genidens (Cuvier, 1829). The potential impact of the pink shrimp fishery at Lagoa do Peixe National Park seemed to be weaker when compared to shrimp fisheries elsewhere. We believe that the decision to prohibit this fishery at the Lagoa do Peixe National Park should not be based on its potential damage to the fish and crab assemblages but based on the simple fact that Brazilian laws do not allow fisheries inside National Parks.

Distribuição espaço-temporal, estrutura populacional e biologia reprodutiva de Callinectes Ornatus Ordway, 1863 na enseada da Fortaleza, Ubatuba (SP), Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)