Performance of the amazonian tambaqui, Colossoma macropomum, in pond polyculture

Abstract

Tambaqui (48%) was reared in polyculture with grass carp (27%) and curimbatá (25%) from 75 g mean weight for a period of 164 days. Ponds of 1200 m 2 were stocked at a total density of 12720 ha −1. Fish were fed with an experimental diet made from soybean and maize at a daily rate calculated as 3% of the tambaqui biomass. Grass carp received chopped angola grass at a daily rate of 15% of live weight. Ponds were weekly manured with 120 kg of mixed cattle and goat manure. Tambaqui reached a final weight of 492 g. Survival rate was 83%. The experimental polyculture had a mean net yield of 7·5 t ha −1 year −1, with apparent conversion rates of 1·13, 5·5 and 7·7 kg kg −1 of diet, grass and manure, respectively. All three species had a high growth rate (from 1·2 to 2·1 % day −1). Tambaqui's growth was affected by the fall in water temperature in the second part of the experiment. Cost/benefit calculations proved the high profitability of the tested semi-intensive polyculture system.