On the feeding ecology of the catfish Hypophthalmus fimbriatus in the blackwater Rio Negro of the Amazon Basin

Abstract

The catfish family Hypophthalmidae, with at Ieast three species, is widely distributed in South America, to which it is confined. The Amazon Basin is the only hydrographical system to contain ali three of the currently recognized species (Oliveira, 1981). Hypophthalmus edentatus (Spix, 1929) is known from the Orinoco, Amazon and La Plata drainages, and H. margi. natus (Valenciennes, 1840) only from the Amazon. Both of these species are food fishes but not very important in total catches in the Amazon Basin, the are a where they are most exploited (Petrere, 1978; Goulding, 1979, 1981 ; Smith, 1979, 1981). ln the large mouth-Iakes of eastern Amazon affluents, such as the Rio Tocantins, however, H. marginatus is the most important species captured (J. L. Carvalho, 1978) *.