A comparative structural cytogenetic study in three allopatric populations of Astyanax scabripinnis (Teleostei: Characidae)

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

Fatores abióticos que afetam a distribuição do gênero Astyanax baird & Girard, 1854 em riachos de cabeceiras de Chapada dos Guimarães, bacia do Rio Cuiabá, Mato Grosso

The main factors that influence the species distribution are related mainly with the dispersion capacity, behavior, presence of other species and to the factors physicist-chemistries. Had been evaluated ecological factors that affect the distribution of the genus Astyanax in Chapada dos Guimaraes headstreams, Cuiaba River basin, Mato Grosso, Brazil. Samples in 27 streams had been made in Chapada dos Guimaraes, and the fish had been collected through the method of electric fish, and the ambient data had been analyzed with one technique of called ordinance of Principal Components Analysis (PCA). 250 individuals had been collect, being 95 A. asuncionensis, 62 A. abramis, 36 A. lineatus and 57 individuals had been captured identified like A. scabripinnis (Jenyns, 1842) sensu Eigenmann, 1927. In relation the ambient characteristics, the variables gotten allowed two axes of the PCA, who explain 53,114 % of the variance of the seven variables analyzed. Axle 1, Main Component 1, explained 31,147 % and Axle 2, Main Component 2, explained 21,967 % of the variation of the ambient data. The formation of axle 1 was influenced positively by the depth and negative by the conductivity and pH. The formation of axle 2 was influenced positively by the Turbidity and negative to the Dissolved Oxygen. The ordinance of the species throughout for the axes corroborated for the understanding of the distribution of specimens.

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.

Efeito de genótipos de caupi, Vigna unguiculata (L.) Walp., sobre o desenvolvimento de Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae)

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

Structural analysis of the Pimelodus maculatus (Lacépède, 1803) embryogenesis (Siluriformes: Pimelodidae)

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

The Role of Mucus in Mytella falcata (Orbigny 1842) Gills from Polluted Environments

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The significance of changes in Mytella falcata (Orbigny, 1842) gill filaments chronically exposed to polluted environments

The impact of pollutants in an organism can be observed by changes in functional complexity at different levels. Bivalve gills are suitable for histopathological analysis because of their structure and function. This study aimed at examining the morphology of Mytella falcata gill filaments from three sites in the Santos estuary (São Paulo, Brazil) with different levels of environmental degradation to identify possible changes in gill structure and discuss the significance of these alterations. For this purpose, histological, histochemical and ultrastructural techniques were used. The filaments of animals from site A (less impacted site) were intact, while in sites B and C, pathological changes were observed, such as: detachment of the epithelium in the intermediate zone, morphological changes of this epithelium, inflammatory process, increase in the number of mucous cells and cell turnover processes. These results suggest that the related changes are an attempt to prevent the entrance of pollutants through gill filaments into the entire organism and that cell turnover is the final way to compensate cell injury. (C) 2008 Elsevier Ltd. All rights reserved

Ontogenetic diet shifts of a Neotropical catfish, Pimelodus maculatus (Siluriformes, Pimelodidae): An ecomorphological approach

This study analyses the ontogenetic diet shifts of a Neotropical catfish, Pimelodus maculatus ( Siluriformes, Pimelodidae), from an ecomorphological standpoint. We collected 241 individuals in the Piracicaba River ( Brazil) and, in the laboratory, seven morphometric variables were recorded from each specimen: standard length (SL), body depth, head length, snout length, eye diameter, mouth height and mouth width. After standardizing these measurements ( as a proportion of SL), linear regressions were run to determine whether their growth was isometric or allometric in relation to SL. The diet analysis shows that the main food item for fish in the smaller size classes is aquatic insects, while the largest individuals feed mainly on other fish. As the great majority of the morphometric variables analyzed showed isometric growth as a function of SL - which means that these fish do not change their shape significantly during their lives - the ontogenetic diet shifts may be seen as a consequence of the absolute size increment of their mouth gape, which allows individuals to maximize their energetic gain by ingesting larger prey with a higher caloric content.

The goatfish Pseudupeneus maculatus and its follower fishes at an oceanic island in the tropical west Atlantic

The influence of a substratum-disturbing forager, the spotted goatfish Pseudupeneus maculatus on the assemblage of its escorting, opportunistic-feeding fishes was examined at Fernando de Noronha Archipelago (tropical west Atlantic). Followers attracted to spotted goatfish foraging singly differed from followers of spotted goatfish foraging in groups in several characteristics. The larger the nuclear fish group, the greater the species richness and number of individuals of followers. Moreover, groups of foraging spotted goatfish attracted herbivores, not recorded for spotted goatfish foraging singly. The size of follower individuals increased with the size and the number of foraging spotted goatfish. The zoobenthivorous habits of the spotted goatfish and its ability to disturb a variety of soft substrata render it an important nuclear fish for several follower species of the reef fish assemblage at Fernando de Noronha. (c) 2006 the Authors Journal compilation (c) 2006 the Fisheries Society of the British Isles.

Evidence of an XX/XY sex chromosome system in the fish Dormitator maculatus (Teleostei, Eleotrididae)

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

Activity of the Ovarian Germinal Epithelium in the Freshwater Catfish, Pimelodus maculatus (Teleostei: Ostariophysi: Siluriformes): Germline Cysts, Follicle Formation and Oocyte Development

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

Alimentação de Serrasalmus maculatus (Kner, 1858) (characiformes; serrasalmidae) no trecho inferior bacia do rio Sorocaba, São Paulo, Brasil

The aim of this study was to discuss aspects of the diet of Serrasalmus maculatus. Fish were collected using gill nets, whose lengths measured 100 m and mesh diameters varied from 3 to 8 cm. A total of 107 individuals were collected. Their length varied from 62 to 210 mm. They were mainly represented by female and immature individuals. No individual was caught in temperatures below 21°C. Four feeding item categories were observed: fish muscle pieces, parts of fish fins, plant fragments, and insects. Comparisons made among individual length classes revealed some significant differences within stomach consumed contents. Individuals whose length exceeded 165 mm consumed only parts of fish muscles and plants. The food availability in the environment and the class lengths amplitude may, however, have influenced the results, in which ontogenetic differences should not be precisely observed.

O Doutorado em matemática no Brasil: um estudo histórico documentado (1842 a 1937)

Pós-graduação em Educação Matemática - IGCE

Aspectos da biologia populacional de Pimelodus maculatus (Teleostei: Siluformes), sob a influência de sitemas de piscicultura em tanques-rede

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Foliculogênese e caracterização celular das classes reprodutivas em Pimelodus maculatus (Siluriformes: Pimelodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)