Hypostomus fluviatilis (Schubart, 1964) é um cascudo (Loricariidae) achado no rio Mogi-Guaçu, Estado de São Paulo. É espécie que pode interessar alguns criadores de peixes, por sua excelente carne. Um total de 47 exemplares (26 machos e 21 fêmeas) foi analisado, capturado de março a setembro de 1975, em Emas, rio Mogi-Guaçu. Alguns caracteres merísticos e outros aspectos biológicos são fornecidos.

Hypostomus fluviatilis (Schubart, 1964) is an armoured catfish (Loricariidae) found in the Mogi-Guaçu river, State of São Paulo, Brazil. It is a species which may interest some fish culturists, due to is excellent meat. A total of 47 specimens (26 males and 21 females), caught from March to September 1975, at Emas Fali, Mogi-Guaçu river, was analyzed. Some meristic characters, together with biological aspects, are presented.

An extensive cuivivation of the cichlids Tilapia rendalli and its predator Cichla ocellaris was undertaken at a lake in the Ribeirão Preto (State of São Paulo) Campus of the University of São Paulo. Comparison of the results with former ones, obtained before the introduction of the predator, showed a considerable increase of tilapias, both in total length and total weight, showing the advantage of rearing them together.

During the spawning period, fishes of the familes Mugilidae and Centropomidae concentrate on the river mouths or brackishwater lagoons. Those species are reared in fish-ponds ("viveiros") in northeastern Brazil, mainly at Pernambuco State. Presently, polyculture trials are made with those species, together with three others of the family Gerridae, with or without artificial feeding or fertilization. The yields are very high per ha /year. A review of the biology of those species, together with the hydrological conditions of the fish-ponds, are presented. The author recommends that similar fish-ponds should be built in other northeastern regions as well as in the south, and the obtention of fry through hypophysation method (now used in Israel and Taiwan for Mugilidae), replacing the present method of simply catching youngs measuring 10 to 15 cm total length and putting them in those fish-ponds. In this way we would contribute to a high and quick production of animal protein, necessary to a great part of Brazilian population.