Occurrence of Atta laevigata (Hymenoptera: Formicidae) in the South of Espirito Santo State, Brazil. Recently Introduced or Endangered Species?

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Early development of Astronotus ocellatus under stereomicroscopy and scanning electron microscopy

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

Chemical attributes of a degraded soil after application of water treatment sludges

Mining is an activity that tends to degrade the environment. The restoration of mining areas, aims to accelerate and improve the succession process according to its future use. The objective of this work was to rehabilitate a soil degraded by tin mining activities in the Amazon Basin (Jamari National Forest, State of Rondonia) with the application of water treatment sludge (WTS), and verify the effect of Sludge on Values of pH (CaCl2 0.01 mol L-1), organic matter, P, Ca, Mg, K, H+Al, and soil micronutrient contents when Cultivated with native plants, legumes, and grass species. A factorial (3 x 5) experimental design was used to optimize the rehabilitation of these areas including three N rates (100, 200, and 300 mg N ka(-1) soil supplied by WTS), five plant species (grasses, legumes, and native plants), and two controls (degraded soil with no fertilizer and degraded soil fertilized with mineral fertilizers), with four replications. WTS increased pH values. The chemical products used to treat the water contributed, in greater extension, to increase soil Ca and Fe contents. The use of WTS as fertilizer proved viable, since it contains nutrients for plants; however, nitrogen Should not be used as a criterion to define the rate of Sludge application, because it is present at small amounts in the WTS.

Metabolic responses to glucoprivation induced by 2-deoxy-D-glucose in Brycon cephalus (Teleostei, Characidae)

The effects of functional cytoglucopenia provoked by 2-deoxy-D-glucose (2-DG) were studied in adult Brycon cephalus, an omnivorous fish from the Amazon Basin in Brazil. Glycogen content in liver and muscle as well as plasmatic glucose, free fatty acids (FFA), insulin, and glucagon were measured. After 48 h fasting, an intraperitoneal saline injection (NaCl 0.6 g/100 ml) was administered to control fish, whereas the experimental group received 2-DG, dissolved in saline, in the dosage of 80 mg/kg (0.487 mmol/kg) or 150 mg/kg (0.914 mmol/kg) body weight; injection volume was 5 ml in all treatments. Blood and tissue samples were taken immediately before, and 2, 8, 10, and 24 h after administration of the drug or saline. Fish injected with both doses of 2-DG showed a marked increase in glycemia levels. Liver and muscle glycogen decreased after 2-DG administration and reached their lowest values 10-24 h after injection, while in control animals no significant changes were observed. Elevation in plasma glucagon was observed only in response to the maximum dosage of 2-DG administered, especially 10 h and 24 h post-injection. Plasma insulin levels were lower in animals treated with the glucose analogue but only statistically significant 24 h after drug administration. In conclusion, the administration of the non-metabolizable glucose analogue 2-DG in B. cephalus is a stimulus to generate responses towards an increase in the glucose available to tissues, which is a characteristic of a fasting situation. All the above data support the interest of 2-DG administration as a model to study carbohydrate metabolism adjustment mechanisms in fish.

Metabolic changes in Brycon cephalus (Teleostei, Characidae) during post-feeding and fasting

Metabolic changes during the transition from post-feeding to fasting were studied in Brycon cephalus, an omnivorous teleost from the Amazon Basin in Brazil. Body weight and somatic indices (liver and digestive tract), glycogen and glucose content in liver and muscle, as well as plasma glucose, free fatty acids (FFA), insulin and glucagon levels of B. cephalus, were measured at 0, 12, 24, 48, 72, 120, 168 and 336 h after the last feeding. At time 0 h (the moment of food administration, 09.00 h) plasma levels of insulin and glucagon were already high, and relatively high values were maintained until 24 h post-feeding. Glycemia was 6.42 +/- 0.82 mM immediately after food ingestion and 7.53 +/- 1.12 MM at 12 h. Simultaneously, a postprandial replenishment of liver and muscle glycogen reserves was observed. Subsequently, a sharp decrease of plasma insulin occurred, from 7.19 +/- 0.83 ng/ml at 24 h of fasting to 5.27 +/- 0.58 ng/ml at 48 h. This decrease coincided with the drop in liver glucose and liver glycogen, which reached the lowest value at 72 h of fasting (328.56 +/- 192.13 and 70.33 +/- 14.13 mumol/g, respectively). Liver glucose increased after 120 h and reached a peak 168 h post-feeding, which suggests that hepatic gluconeogenesis is occurring. Plasma FFA levels were low after 120 and 168 h and increased again at 336 h of fasting. During the transition from post-feeding to fast condition in B. cephalus, the balance between circulating insulin and glucagon quickly adjust its metabolism to the ingestion or deprivation of food. (C) 2002 Elsevier B.V. All rights reserved.

A novel ZZ/ZW sex chromosome system for the genus Leporinus (Pisces, Anostomidae, Characiformes)

A wide range of sex chromosome mechanisms, including simple and multiple chromosome systems is characteristic of fishes. The Leporinus genus represent a good model to study sex chromosome mechanisms, because an unambiguous ZZ/ZW sex chromosome system was previously described for seven species, while the remaining studied species of the genus do not show differentiated sex chromosomes. The occurrence of sex chromosomes in Leporinus trifasciatus and Leporinus sp2 from the Araguaia river, Amazon basin, Brazil, was here investigated. ZZ/ ZW sex chromosomes were detected for both species. The Z and W chromosome morphology of L. trifasciatus is the same as described for other species of the genus Leporinus. However, the Z and W chromosomes of L. sp2 were quite different in their morphology and banding pattern suggesting that the ZW system of this species have originated independently from the ZW system previously described for other Leporinus.

Molecular systematic and historical biogeography of the armored Neotropical catfishes Hypoptopomatinae and Neoplecostominae (Siluriformes: Loricariidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variability of 18S rDNA locus among Symphysodon fishes: chromosomal rearrangements

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genus Paracoccidioides: Species Recognition and Biogeographic Aspects

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

Comparative cytogenetics of ten species of cichlid fishes (Teleostei, Cichlidae) from the Araguaia River system, Brazil, by conventional cytogenetic methods

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

Gene flow networks among American Aedes aegypti populations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Paleodistributions and Comparative Molecular Phylogeography of Leafcutter Ants (Atta spp.) Provide New Insight into the Origins of Amazonian Diversity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spatial and temporal distribution of fishing resources exploited by the Manaus fishing fleet, Amazonas, Brazil

Recursos pesqueiros são importantes fontes de renda e alimento para as populações rurais e urbanas na Amazônia. O presente trabalho avalia a pesca e as variáveis ambientais que determinam a produção de pescarias que desembarcam em Manaus, e avalia também a abundância relativa de recursos pesqueiros em diferentes subsistemas na Amazônia Central. A informação coletada no porto de desembarque de pescado de Manaus foi utilizada para testar um novo índice de captura obtido a partir de um modelo de covariância que apresentou as seguintes variáveis significativas: número de pescadores/dia (dias de pesca vezes número de pescadores por viagem); distância do pesqueiro até Manaus; quantidade de gelo que usou durante a viagem; e nível de rio. Não houve nenhuma diferença significativa entre valores médios de captura entre os subsistemas do Purus, Madeira e de Juruá. Estes resultados sugerem que os tributários da margem direita são similares e mais produtivos em termos comerciais. Concluiu-se que a produção corrente varia de acordo com a magnitude de esforço pesqueiro, por variações ambientais, assim como por aspectos operacionais da pesca, particularmente o consumo de gelo.

Características das águas subterrâneas numa faixa norte-sul na cidade de Manaus (AM)

A cidade de Manaus está localizada numa região próxima ao centro da bacia Amazônica, cujo abastecimento de água é realizado pelas águas do Amazonas, sendo efetuado por captação da drenagem superficial do rio Negro e por poços tubulares, que exploram aqüíferos constituídos pela Formação Alter do Chão. Com o objetivo de investigar a hidroquímica das águas subterrâneas de Manaus, para caracterizar e avaliar a qualidade dos recursos hídricos em subsuperfície, aferiram-se os parâmetros físicos, físico-químicos e químicos das amostras de águas de poços tubulares selecionados. Os resultados obtidos dos parâmetros analisados mostraram que as águas estudadas são excelentes para consumo humano e industrial, por situarem-se dentro dos limites de potabilidade estabelecidos pela legislação vigente.

Classificação fitogeográfica das florestas do Alto Rio Xingu

Este trabalho propõe a inclusão da categoria Floresta Estacional Perenifólia no sistema oficial de classificação da vegetação brasileira, devido às particularidades florísticas e fisionômicas da floresta da borda sul-amazônica, que atinge maior amplitude geográfica na região do Alto Rio Xingu. Para justificar essa inclusão são apresentadas as características ambientais (clima, solo, hidrologia) e diferenças fisionômicas e florísticas entre as florestas do Alto Xingu e demais florestas ombrófilas da Bacia do Amazonas e estacionais do Planalto Central.