The potential growth and production of "jaraquis" Semaprockilodus, spp in a "terra firme" stream impoundment with chemically poor waters was evaluated. The waster water from pig stys wasused as a surce 0f food and organic manure. During the. experimental period of 383 days at a stocking density of 1 fish/m2 the production obtained was 1277 Kg/ha. The fishes in the impoundment presented similar growth to those from lakes and rivers. The "jaraquis" are promising candidates for fish culture in the Amazon.