Résumé
ABSTRACT Most information on catfishes of the genus Aspidoras has focused species kept in aquaria, in non-natural conditions. Biotic and abiotic parameters of environment inhabited by Aspidoras fuscoguttatus, associated ichthyofauna, as well as strategies involved in the successful occupation of different microhabitats in a first order stream, located in São José do Rio Preto, São Paulo State, were investigated. Data collection was monthly performed at three segments (headwaters, middle course, and mouth) from August 1999 to July 2000. The greatest values of water temperature, conductivity, turbidity, alkalinity, width, depth, and current velocity were obtained in the rainy season. Dissolved oxygen levels showed significant differences among three segments in all sampling months, except for September. Substrate composition was predominantly sandy, followed by silt and clay in middle course and mouth in rainy as much as in dry seasons. In headwaters a large increase of the sandy fraction occurred in the rainy season. In the marginal and aquatic vegetation 30 species of macrophytes and 5 of macroalgae were identified. The fauna included tadpoles of Anura and macroinvertebrates (Mollusca, Crustacea, Arachnida, and 8 orders of Insecta). A. fuscoguttatus was found throughout the entire stream in sympatry with 6 fish species. In middle course, cluster analysis revealed an association between A. fuscoguttatus immatures and low depth, suggesting a probable function of depth in that stage of ontogenetic development of catfishes. The results indicate that A. fuscoguttatus present plasticity in terms of microhabitat, including air breathing behavior in hypoxic conditions, previously unknown in genus Aspidoras.
Sujets)
Animaux , Poissons-chats , Rivières , Écologie , Conductivité électrique , Concentration en ions d'hydrogène , Saisons , TempératureRésumé
São analisadas as características microscópicas entre os caules de Lippia alba e de Melissa officinalis, ambas conhecidas no Brasil como "ervas cidreiras" e consumidas pela população em virtude de suas propriedades sedativas e antiespasmódicas. A análise dos cortes transversais dos seus caules, que geralmente aparecem misturados às folhas das duas espécies em estudo, auxilia a diagnose da matéria prima vegetal.
The microscopic characteristics of the stems of Lippia alba and Melissa officinalis, both known in Brazil as "erva cidreira" and consumed by the population in virtue of their sedative and antispasmodic properties, were analyzed. Analysis of the transverse section these stems, which often appear mixed with the leaves of the two species, help in the differentiation of the raw plant material.
Résumé
Dosagens de hormônios tireoideanos empregando-se a técnica de radioimunoensaio (RIA) foram realizadas em 106 bovinos mestiços Zebu, machos, castrados, provenientes de duas áreas fisiográficas do Estado de Minas Gerais, abatidos em matadouro comercial. Os valores médios de tiroxina e de triiodotironina foram 9,45 mais ou menos 2,58 mcg/dl e 158,41 mais ou menos 34,26 ng/dl, para os animais do Triângulo Mineiro, e 6,98 mais ou menos 1,95 mcg/dl e 121,35 mais ou menos 33,07 ng/dl, para os do Norte do Estado, respectivamente