Resumo em Inglês:
Rhythmic activity patterns are demonstrated for 15 species of fish in várzea lakes of the Solimões river by analyzing catch per hour-of-day data. Supplemented by visual observation, an array of six gillnets of equal length but different mesh size was used for collecting. The data, in general, show a bimodal pattern of activity. The two peaks of catch can be related to movement during twilight periods, while low catches can be ascribed to reduced activity during times close to mid-day or night Observed activity peaks correspond to local displacements of fish between feeding and shelter sites. In the case of piscivorous fishes, activity peaks could be explained by facility in prey localization, which is greatest during twilight periods when prey species are moving.Resumo em Inglês:
The Stannius corpuscles of Prochilodus scrofa are studied microscopically (both optically and electronically) as well as macroscopically. Two CS, and sometimes 3 or 4, are found per animal. They are pink-coloured organs, rounded in shape and scattered laterally in the first anterior third of the kidney. Each CS is enveloped by a thick connective tissue capsule. The grandular parenchyma consists of only one cellular (PAS-/AF-) type, cylindrical in shape, with oval or rounded nucleus located eccentrically with visible nucleolus. The ultrastructural description is as follows: well developed Golgi complexes, rough endoplasmic reticulum and mitochondria in moderate quantities. Electron-dense granules numerous. CS highly vascularized.Resumo em Inglês:
Hyla ranki, sp. n., is described from the state of Minas Gerais, southeastern Brazil. This new species resembles Hyla rizibilis Bokermann, 1964. The advertising call and the tadpole are also described. Observations on the biology of the new species are referred and the recognition of the group rizibilis, constituted by H. rizibilis and H. ranki, sp. n., is proposed. Hyla mirim B. Lutz, 1972 is synonymized with H. rizibilis.Resumo em Inglês:
The case of the Indigo, or Lear's Macaw, Anodorhynchus leari, is unique in South American ornithology. The species, although described more than 100 years ago, was known only through very few living specimens, which entered occasionally the bird trade, without any indication of their origins. It was presumed "probably some part of Brazil" (Salvadori, 1891). The last speculation was that it was unlikely, though not impossible, that the Indigo Macaw might not be an independem species, but rather, a hybrid between the two other well known blue macaws, Anodorhynchus hyacinthinus and A. glaucus (Voous, 1965).