Estuarization increases functional diversity of demersal fish assemblages in tropical coastal ecosystems.

This study assessed the influence of the seasonal fluctuation of abiotic conditions (wet v. dry season) on the functional diversity (FD) of tropical coastal fish assemblages. Sampling was carried out in three regions of north-east Brazil with contrasting coastlines (influenced by reef, lagoon and estuary). In each region, fishes were sampled from three depth strata (10, 20 and 30 m) and FD was estimated using an index based on key phenotypic and behavioural characteristics. All three regions had higher FD in the wet season at shallower depths, indicating the coexistence of species with low functional redundancy in sites subject to seasonal flushing of fresh water. Deeper sites had lower FD than shallower sites, although this difference was less pronounced for region 3, which is strongly affected by its proximity to the São Francisco estuary. The results broadly support the hypothesis that alterations in abiotic conditions in the wet season allow estuarine-adapted fishes with a different suite of functional traits to invade shallow coastal regions.

Spatial population structure of the Neotropical tiger catfish Pseudoplatystoma metaense: skull and otolith shape variation.

Using geometric morphometrics, the skull and otolith of tiger catfish Pseudoplatystoma metaense were analysed to identify population structure in tributaries of the Apure River (i.e. the Sarare, Caparo, Guanare, Portuguesa and San Carlos Rivers) in the Orinoco basin, Venezuela. The analyses show uniformity in skull and otolith shapes of P. metaense within and among four tributaries, with only the Caparo River showing significant differences. Within the Apure basin, the stock of P. metaense was differentiated through spawning, refuge and nursery areas. This study concludes that populations of P. metaense from each major tributary in the Orinoco basin should be considered as part of a metapopulation system for management purposes. Human disturbances in the catchment have directly reduced the spawning areas available to this species, decreased the total biomass and changed the spatial distribution of spawning areas.

Fish and aquatic habitat conservation in South America: a continental overview with emphasis on neotropical systems.

Fish conservation in South America is a pressing issue. The biodiversity of fishes, just as with all other groups of plants and animals, is far from fully known. Continuing habitat loss may result in biodiversity losses before full species diversity is known. In this review, the main river basins of South America (Magdalena, Orinoco, Amazon and Paraná-La Plata system), together with key aquatic habitats (mangrove-fringed estuaries of the tropical humid, tropical semi-arid and subtropical regions) are analysed in terms of their characteristics and main concerns. Habitat loss was the main concern identified for all South American ecosystems. It may be caused by damming of rivers, deforestation, water pollution, mining, poor agricultural practice or inadequate management practice. Habitat loss has a direct consequence, which is a decrease in the availability of living resources, a serious social and economic issue, especially for South American nations which are all developing countries. The introduction of exotic species and overfishing were also identified as widespread across the continent and its main freshwater, coastal and marine ecosystems. Finally, suggestions are made to find ways to overcome these problems. The main suggestion is a change of paradigm and a new design for conservation actions, starting with integrated research and aiming at the co-ordinated and harmonized management of the main transboundary waters of the continent. The actions would be focused on habitat conservation and social rescue of the less well-off populations of indigenous and non-indigenous peoples. Energy and freshwater demands will also have to be rescaled in order to control habitat loss.

Amazonian plants from Peru used by Quechua and Mestizo to treat malaria with evaluation of their activity.

Indigenous Quechua and Mestizo populations from distinct areas in Loreto, Peru, were interviewed about traditional medication for the treatment of malaria. An ethnographic survey concerning the native theory of illness aetiology in the specific case of malaria permitted the elaboration of an efficient ethnopharmacological enquiry. The survey took place on three main zones corresponding to villages on the Napo and the Pastaza rivers (for the Quechua), and in the surroundings of Iquitos (for the Mestizos) and led to the collection of 14 plants. Serial extractions in hexane, dichloromethane, and methanol were performed on the different parts of the plants collected. The extracts were then tested for antiplasmodial activity in vitro. Seven plants displayed antiplasmodial activity (IC(50) from 2 to 25 microg/mL) and usually low cytotoxicity, indicating their antiplasmodial specificity. The results give scientific validation to the traditional medical knowledge of Quechua and Mestizo populations from Loreto and confirm a source of potentially active plants.

Temporal and spatial patterns on serra, Scomberomorus brasiliensis (Teleostei, Scombridae), catches from the fisheries on the Maranhão coast, Brazil

The displacement pattern of the serra, Scomberomorus brasiliensis, in North-eastern Brazil was analyzed from landing data recorded from the fleet fishing serra. Serra fishery has two seasons: from September to February (demersal species plus serra), and from March to August (almost only large amounts of serra). S. brasiliensis relative abundance increases similarly along the coast from March, but decreases first on the West coast from June. Records indicate that serra is near the coast at least until September/October in Eastern grounds. From October to March (strongest spawning season) there is no record of shoals on the coast. We concluded that the Maranhão coast is just a part of the migration circuit of S. brasiliensis that may exceed 300 nautical miles.

O padrão de deslocamento da serra, S. brasiliensis, no Nordeste do Brasil foi analisado a partir de dados registrados pela frota pesqueira direcionada a sua captura. Há duas estações principais de pesca: de setembro a fevereiro (pesca das espécies demersais e serra) e de março a agosto (praticamente apenas grandes capturas de serra). A abundância de S. brasiliensis aumenta semelhantemente ao longo da costa desde março, mas ocorreu diminuições na costa Ocidental desde junho. Registros indicam que a serra está mais perto da costa, pelo menos até setembro/outubro, nos pesqueiros da costa norte-oriental. De outubro a março (estação de desova mais intensa), não há registro de cardumes na costa. A partir dos padrões observados na pesca maranhense e nas informações da literatura, concluímos que a costa do Maranhão é apenas uma parte do circuito de migração de S. brasiliensis nas águas do Nordeste do Brasil, sendo que o circuito total deve ser superior a 300 milhas náuticas.

Temporal and spatial patterns on serra, Scomberomorus brasiliensis (Teleostei, Scombridae), catches from the fisheries on the Maranhão coast, Brazil

The displacement pattern of the serra, Scomberomorus brasiliensis, in North-eastern Brazil was analyzed from landing data recorded from the fleet fishing serra. Serra fishery has two seasons: from September to February (demersal species plus serra), and from March to August (almost only large amounts of serra). S. brasiliensis relative abundance increases similarly along the coast from March, but decreases first on the West coast from June. Records indicate that serra is near the coast at least until September/October in Eastern grounds. From October to March (strongest spawning season) there is no record of shoals on the coast. We concluded that the Maranhä¯ácoast is just a part of the migration circuit of S. brasiliensis that may exceed 300 nautical miles

Temporal and spatial patterns on serra, Scomberomorus brasiliensis (Teleostei, Scombridae), catches from the fisheries on the Maranhão coast, Brazil.

The displacement pattern of the serra, Scomberomorus brasiliensis, in North-eastern Brazil was analyzed from landing data recorded form the fleet fishing serra. Serra fishery has two seasons: from Septemer to February (demersal species plus serra), and from March to August (almost only large amounts of serra). S. brasilienisis relative abundance increases similarly along the coast from March. but decreases first on the West coast from June. Records indicate that serra is near the coast at least until September/October in Eastern grounds. From October to March (strongest spawning season) there is no record of shoals on the coast. We concluded that the Maranhão coast is just a part of the migration circuit of S. brasilienisis that may exceed 300 nautical miles.

Temporal and spatial patterns on serra, Scomberomorus brasiliensis (Teleostei, Scombridae), catches from the fisheries on the Maranhão coast, Brazil

The displacement pattern of the serra, Scomberomorus brasiliensis, in North-eastern Brazil was analyzed from landing data recorded from the fleet fishing serra. Serra fishery has two seasons: from September to February (demersal species plus serra), and from March to August (almost only large amounts of serra). S. brasiliensis relative abundance increases similarly along the coast from March, but decreases first on the West coast from June. Records indicate that serra is near the coast at least until September/October in Eastern grounds. From October to March (strongest spawning season) there is no record of shoals on the coast. We concluded that the Maranhão coast is just a part of the migration circuit of S. brasiliensis that may exceed 300 nautical miles.

O padrão de deslocamento da serra, S. brasiliensis, no Nordeste do Brasil foi analisado a partir de dados registrados pela frota pesqueira direcionada a sua captura. Há duas estações principais de pesca: de setembro a fevereiro (pesca das espécies demersais e serra) e de março a agosto (praticamente apenas grandes capturas de serra). A abundância de S. brasiliensis aumenta semelhantemente ao longo da costa desde março, mas ocorreu diminuições na costa Ocidental desde junho. Registros indicam que a serra está mais perto da costa, pelo menos até setembro/outubro, nos pesqueiros da costa norte-oriental. De outubro a março (estação de desova mais intensa), não há registro de cardumes na costa. A partir dos padrões observados na pesca maranhense e nas informações da literatura, concluímos que a costa do Maranhão é apenas uma parte do circuito de migração de S. brasiliensis nas águas do Nordeste do Brasil, sendo que o circuito total deve ser superior a 300 milhas náuticas.