Occurrence and ultrastructural characterization of nuage during oogenesis and early spermatogenesis of Piaractus mesopotamicus Holmberg, 1887 (Teleostei)

Foi investigada a ocorrência e caracterizada ultra-estruturalmente a eliminação de material nuclear eletrondenso (nuage) para o citoplasma durante a ovogênese e durante os estágios iniciais da espermatogênese de Piaractus mesopotamicus, um peixe do Pantanal Matogrossense de ciclo reprodutivo sazonal. Constataram-se nas células germinativas femininas dois momentos de eliminação desse material, na ovogônia e no ovócito em fase perinucleolar. Nas células masculinas, material com morfologia e comportamento muito semelhante foi encontrado na espermatogônia. em todos os casos, o material associou-se a mitocôndrias. A possível função desse material foi discutida.

Occurrence of Three Haplotypes of Linepithema micans (Forel) (Hymenoptera: Formicidae) in Southern Brazil

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

Occurrence and morphometry of the hypopharyngeal glands in Scaptotrigona postica Lat. (Hymenoptera, Apidae, Meliponinae)

As compared to Apis mellifera where only workers have hypopharyngeal glands, in Scaptotrigona postica, these glands occur in workers, queens and males. They are composed of two long axial ducts with many unicellular secretory alveoli interconnected by secretory canaliculi. The axial ducts are longer in miles than in workers, but the alveolar areas of queens and males are generally smaller. In workers the alveoli have their greatest size in the nurses or middle-aged individuals while in queens and males they are larger in newly emerged individuals. The results indicate that the glands in workers may produce food for the brood as in A. mellifera, since they are well developed in the nurse workers. However, the function of the glands in queens and males remains to be clarified since these individuals have no part in brood care.

Occurrence of Winged Forms of Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae) in Laboratory Colonies

Foi observada, pela primeira vez no Brasil, a produção de centenas de formas aladas em formigueiros de Atta sexdens rubropilosa Forel, mantidos em laboratório. Larvas de último instar de machos foram encontradas em 5 de agosto de 2000 em um formigueiro com quase seis anos de fundação, contendo aproximadamente 110 L de esponja de fungo distribuída em 21 panelas. Entre 30 e 40 dias mais tarde apareceram larvas de fêmeas aladas. Os adultos sexuados apresentaram tamanhos compatíveis com os encontrados em formigueiros de campo. Foram observadas duas aparentes tentativas frustradas de revoada na última semana de outubro, após o que começaram a aparecer machos e fêmeas mortos no lixo do formigueiro.

Occurrence of hyphomycetes and actinomycetes in red-yellow latosol from a cerrado region in Brazil

A study to quantify the populations of filamentous fungi and actinomycetes was undertaken in a cerrado area, in Corumbatai county, São Paulo, at different depths of medium-textured red-yellow latosol, correlating them to humidity, organic matter, pH of the soil and climatic factors. The technique used was the serial dilution of composite soil samples (n=4), using Martin's medium with streptomycin for filamentous fungi and a starch medium for actinomycetes. The number of filamentous fungi was more abundant in the first soil layer, 0-5 cml compared to the other depths. The number of actinomycetes was higher between 5 cm and 50 cm depth. There were two-monthly variations in the number of filamentous fungi and actinomycetes. A sharp drop in fungi was found in May 1988 at all depths of the soil, when there was lower air temperature and an atypically high monthly rainfall for this period in the cerrado. Statistically significant and directly proportional correlations were obtained between the number of actinomycetes and the rainfall at depths of 0 to 5 cm and 50 to 100 cm. The results obtained in the different soil layers to 100 cm depth demonstrated the importance of the first 5 cm layer due to the heavy concentration of microorganisms, mainly the filamentous fungi, together with the highest organic matter content.

Occurrence of freshwater stingrays (Chondrichthyes: Potamotrygonidae) in the Uruguay River and its tributaries, Uruguay, South America.

Four records of potamotrygonids in the Uruguay River and its tributaries in Paysandu, Uruguay are reported in this paper. The first one was a specimen caught in 1934, of undetermined sex and weighing 120 kg and with a disc width of ca 150 cm. The second specimen, caught in 1998, was also of undetermined sex; it weighed 50 kg total weight and its disc width measured 103 cm. The third specimen was caught in 2001; it was an adult male, weighed 114 kg total weight and its disc width measured ca 110 cm. The fourth one, caught in 2004, was a female, 11 kg in total weight and with a disc width of 80 cm. According to the size and general description, specimens were identified as Potamotrygon brachyura, to date the only potamotrygonid confirmed for Uruguay.

Spatio-temporal segregation and size distribution of fish assemblages as related to non-native species occurrence in the middle rio Doce Valley, MG, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Occurrence of the bentfin devil ray, Mobula thurstoni (Chondrichthyes : Mobulidae), in the western Atlantic

This paper reports the occurrence of the fifth species of Mobula in the western Atlantic, M. thursloni, based on specimens caught by artisanal and driftnet fisheries in coastal waters off southern Brazil.

Occurrence of Hymenoptera on Sus scrofa carcasses during summer and winter seasons in southeastern Brazil

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

Occurrence and behavior of butyltins in intertidal and shallow subtidal surface sediments of an estuarine beach under different sampling conditions

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

Visceral pigmentation in four Dendropsophus species (Anura: Hylidae): Occurrence and comparison

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

The cyanobacterial genus Cyanoarbor Wang (Chroococcales, Entophysalidaceae) and its occurrence in Brazil

The new cyanobacterial species Cyanoarbor violascens was found and described from subaerophytic habitats (wet lateritic soils) in the northwest region of São Paulo State, Brazil. The phenotypic generic features of the population were confirmed and the genus Cyanoarbor Wang 1989 was revised with four species recognized. Cyanoarbor rupestris Wang was first described from subaerophytic habitats in China. Cyanoarbor violascens Branco sp. nov. is here described from subaerophytic habitats (wet lateritic soils) in the northwest region of São Paulo State, Brazil, differing from other species by violet-coloured sheaths, cell sizes and ecotopic preference. Additionally, material previously identified as Chlorogloea cf. microcystoides from Nepal was recognized as belonging to Cyanoarbor and is here described as C. himalayensis M. Watanabe et Komdrek sp. nov. Chlorogloea gessneri Schiller is transferred to the genus Cyanarbor, as C. gessneri (Schiller) nov. comb. All four species can be differentiated based on a combination of morphological characters and biotopic preferences. Descriptions and an identification key of the four species of this genus are provided.

New occurrence of the rare genus Doliocatella (Stigonematales, Cyanophyceae)

A new occurrence of the genus Doliocatella (Cyanophyceae, Cyanobacteria) is reported. The type species of the genus, D. formosa, is described from a stream of the tropical Amazonian rainforest (Manaus, Amazonas State, Brazil). A detailed taxonomic description with photomicrographs and ecological characteristics are provided based on the three worldwide species records. D. formosa is characterized by the presence of uniseriate main filaments, cylindrical branches, and mostly cylindrical cells; heterocytes are absent. D. formosa occurs under limited and special conditions, i.e. habitats with low pH and relatively high temperatures. The species has a restricted ecological distribution, limited to tropical lotic ecosystems, but it is found over a relatively wide geographical range.

Reproductive behavior and seasonal occurrence of Psecas viridipurpureus (Salticidae, Araneae)

O comportamento reprodutivo e a ocorrência sazonal de Psecas viridipurpureus foram estudados na Estação Ecológica do Noroeste Paulista, uma pequena área de conservação na região noroeste do Estado de São Paulo, Brasil (49º22'50W e 20º48'36S). P. viridipurpureus ocorreu em gravatás, uma bromeliácea (Bromelia balansae, Bromeliaceae) que não acumula água de chuva. Durante a exibição de corte, o casal ocupou a região mediana das folhas de gravatás, com o macho sempre localizado em uma posição superior à da fêmea. Os machos de P. viridipurpureus apresentaram um comportamento de corte complexo, que incluiu cinco padrões motores. O comportamento de corte e a cópula ocorreram preponderantemente durante a estação chuvosa e o recrutamento de jovens entre dezembro e julho. O abrigo de P. viridipurpureus difere do padrão de Salticidae, pois as ootecas são recobertas por uma cobertura de seda plana e não são incluídas em casulos.

Occurrence and geochemistry of metamafic rocks from the Forquilha Eclogite Zone, central Ceara (NE Brazil): geodynamic implications

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)