Estudo histológico e histoquímico do aparelho excretor de Glossoscolex paulistus Michaelsen, 1926 (Oligochaeta, Glossoscolecidae)

The present study reveals that the excretory system of Glossoscolex paulistus is formed by open holonephridia (exonephridia). It is noticed that different zones are recognized in the nephridial canal, with defined histological and histochemical characteristics: 1) primary canal; 2) lobed canal; 3) first rounded segment; 4) afferent thin segment; 5) efferent thin segment; 6) second rounded segment; 7) ciliary tube; 8) clear canal; 9) pigmented canal; 10) intermediate canal; 11) bladder; 12) terminal canal; 13) nephridiopore. All these regions are intercellular and cilia are found in regions 1, 2, 3, 6, 7 and 13. The connections between afferent and efferent capillary of the vascular supply of the nephridium are made of capillary loops and dilatations which we call glomeruli in this paper. Filtering functions are suggested for the glomerulus. The response of the lobed canal and the first and second rounded segments to Gomori's reaction is strongly positive and this is found to coincide with the largest concentration of glomeruli in the main loops 1 and II, that suggests a higher filtration capacity for the canal and segments.

Oxygen uptake of active and aestivating earthworm Glosso scolex pa ulistus (Oligochaeta, Glossoscolecidae)

1. 1. The onset of or reactivation from aestivation in the earthworm Glossoscolex paulistus were dependent upon soil moisture. No evidence of temperature effect in the process was found either in field or laboratory data. 2. 2. Oxygen uptake measured in active and aestivating groups revealed remarkable reduction for aestivating earthworms at various temperatures studied. 3. 3. No evidences of temperature compensation in oxygen uptake was found in both groups of earthworms, indicating that reduction in oxygen uptake is the only adaptation for the aestivating G. paulistus. © 1985.

Colonização por macroinvertebrados bentônicos em substrato artificial e natural em um riacho da serra de Itatinga, São Paulo, Brasil

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

Benthic macroinvertebrates in the Paranapanema reservoir cascade (southeast Brazil)

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

Controlling factors of benthic macroinvertebrates distribution in a small tropical pond, lateral to the Paranapanema River (São Paulo, Brazil).

The aim of the present study was to examine the benthic fauna in a marginal pond lateral to the Paranapanema River and to identify the main controlling factors of its distribution. Considering the small size of the lacustrine ecosystem, we expected that seasonal variations of the benthic community attributes are more important than spatial variations; Methods: Two samplings, one in March and another in August, were carried out at nine sites in the pond. Sediment samples were obtained through a Van Veen grab for invertebrate sorting, granulometric analysis, and for quantification of organic matter in sediment. Other abiotic factors were measured, such as water transparency, dissolved oxygen, pH, electric conductivity, temperature, and depth of sediment sampling sites. Regarding the comparative analysis at spatial scale, no significant variations in density of the benthic invertebrate community were found. Results: In relation to the studied abiotic factors, only depth presented significant differences among sampling sites; All the measured environmental parameters presented significant differences among sampling months, except depth and the physical and chemical characteristics of the sediment. The abundance of Chaoboridae and Chironomidae was the unique attribute with a significant difference in comparing the two months. A higher abundance of taxa occurred in August, especially for Oligochaeta, Nematoda, Chaoboridae, and Chironomidae; Conclusions: Because of the low structural complexity of the studied pond, we concluded that the changes in benthic macroinvertebrate community attributes were mainly due to seasonal effects.

Colonization of rocky and leaf pack substrates by benthic macroinvertebrates in a stream in southeast Brazil.

A comparative analysis was conducted of the colonization by benthic macroinvertebrates of rocky and leaf pack substrates, both natural and artificial. This colonization was evaluated by season, with the objective of ascertaining the influence of rainfall on the rate of colonization. The total density of macroinvertebrates after 21 days of colonization was significantly greater in the dry than in the wet season. When the substrate types were compared, artificial leaf pack substrate presented the smallest density for both seasons. In the wet season, Chironomidae, Leptohyphidae, Hydropsychidae, Elmidae, immature stages of Trichoptera, and Hydroptilidae showed a more representative density. In the dry season, Chironomidae, Baetidae and Oligochaeta were the most abundant taxa. The artificial rocky substrate used in this experiment was the most appropriate, due to its resemblance with natural substrate conditions in terms of the maintenance of the structural integrity of the substrate throughout the experimental period. Successional and seasonal effects were of great relevance, playing an important role in the colonization process.

Urea-induced unfolding of Glossoscolex paulistus hemoglobin, in oxy- and cyanomet-forms: A dissociation model

The urea effect on the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) stability was studied by analytical ultracentrifugation (AUC) and small angle X-ray scattering (SAXS). AUC data show that the sedimentation coefficient distributions curves c (S), at 1.0mol/L of urea, display a single peak at 57 S, associated to the undissociated protein. The increase in urea concentration, up to 4.0mol/L, induces the appearance of smaller species, due to oligomeric dissociation. The sedimentation coefficients and molecular masses are 9.2S and 204kDa for the dodecamer (abcd)3, 5.5S and 69kDa for the tetramer (abcd), 4.1S and 52kDa for the trimer (abc) and 2.0 S and 17kDa for the monomer d, respectively. SAXS data show initially a decrease in the I(0) values due to the oligomeric dissociation, and then, above 4.0mol/L of denaturant, for oxy-HbGp, and above 6.0mol/L for cyanomet-HbGp, an increase in the maximum dimension and gyration radius is observed, due to the unfolding process. According to AUC and SAXS data the HbGp unfolding is described by two phases: the first one, at low urea concentration, below 4.0mol/L, characterizes the oligomeric dissociation, while the second one, at higher urea concentration, is associated to the unfolding of dissociated species. Our results are complementary to a recent report based on spectroscopic observations. © 2012 Elsevier B.V.

Macroinvertebrados aquáticos associados à Eichhornia azurea (Swartz) Kunth e suas relações com as variáveis abióticas em ecossistemas lênticos marginais (São Paulo, Brasil)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Thermal denaturation and aggregation of hemoglobin of Glossoscolex paulistus in acid and neutral media

The thermal denaturation and aggregation of the HbGp, in the oxy- and cyanomet-forms, was investigated by DSC, AUC, DLS, optical absorption and CD, in the pH range from 5.0 to 7.0. Oxy-HbGp has a denaturation process partially reversible and dependent on the temperature. DSC melting curve is characterized by a single peak with Tc value of 333.4±0.2K for oxy-HbGp, while two peaks with Tc values of 332.2±0.1 and 338.4±0.2K are observed for cyanomet-HbGp, at pH 7.0. In acidic pH oxy- and cyanomet-HbGp are more stable showing higher Tc values and aggregation. AUC data show that, HbGp, at pH 7.0, upon denaturation, remains undissociated at 323K, presenting oligomeric dissociation at 333 (12±3% of tetramer and 88±5% of whole HbGp) and 343K (70±5% of monomer and 30±2% of trimer). DLS data show that the lag period before aggregation is dependent on the temperature and HbGp concentration. Optical absorption and CD results show that the increase of temperature leads to the oxy-HbGp oxidation and aggregation, above 331K, in acidic pH. CD data, for HbGp, present a greater thermal stability in acid medium than at neutral pH, with similar Tc values for both oxidation forms. Our data are consistent with previous studies and represents an advance in understanding the thermal stability of oligomeric HbGp structure. © 2012 Elsevier B.V.

Comunidade de macroinvertebrados bentônicos e qualidade da água e do sedimento das bacias hidrográficas dos rios Lavapés, Capivara, Araquá e Pardo, município de Botucatu(SP) e região

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo comparativo das associações de macroinvertebrados bentônicos e do sedimento dos reservatórios de Chavantes e Salto Grande (rio Paranapanema, SP, PR) e avaliação toxicológica da água e sedimento

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A fauna de macroinvertebrados bentônicos em uma lagoa marginal ao rio Paranapanema, na zona de desembocadura na represa de Jurumirim (SP, Brasil): se tiver subtitulo

O presente estudo teve como objetivos principais analisar a biodiversidade de macroinvertebrados bentônicos em diferentes pontos localizados no fundo da Lagoa do Mian, zona de desembocadura do rio Paranapanema, na Represa de Jurumirim, Estado de São Paulo. Nove pontos de amostragem ao longo da lagoa foram selecionados, distribuídos em três transectos. Cada transecto possuía um ponto na margem direita, um ponto na margem esquerda e um ponto no meio. As coletas foram realizadas em dois períodos do ano, um em março e outro em agosto, para fins de comparação. 2009 representou um ano atípico com relação aos níveis pluviométricos, ocorrendo chuvas intensas no período de julho (um mês tipicamente seco). Foram medidas as variáveis físico-químicas da água, tais como: transparência, profundidade, oxigênio dissolvido, pH, condutividade elétrica e temperatura. Foram recolhidas amostras do sedimento para análise da fauna bentônica e análise do sedimento (quantidade de matéria orgânica presente e granulometria) utilizando-se a draga de Petersen. O material foi triado sob microscópio estereoscópico. A seguir, foi feita a identificação e contagem dos indivíduos. Medidas de densidade, abundância relativa, riqueza, diversidade e equitabilidade foram calculadas. A análise mostrou maior abundância dos táxons no mês de agosto, apontando para a predominância de alguns grupos, como Chaoboridae, Nematoda, Oligochaeta e Chironomidae, este último apenas no segundo mês de coleta. A distribuição dos organismos foi mais significativamente influenciada pela a condutividade elétrica da água, pela transparência, pelo oxigênio dissolvido e por características do sedimento

Sazonalidade climática e os efeitos na helmintofauna parasita de Dendropsophus nanus (Anura: Hylidae) da RPPN Foz do rio Aguapeí, município de Castilho, São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)