Piscicultura integrada na Amazônia: favorecimento à produção de perifiton e seus efeitos no crescimento do jaraqui de escama grossa em monocultivo e policultivo com tambaqui

Abstract

Periphyton-based aquaculture is that in which artificial or natural substrates are used in order to benefit fish, periphyton food sources in integrated culture. Theoretically, periphyton-based culture systems could enhance the conversion of primary food production into fish biomass, making the system more efficient and economical. The aim of the present study was to investigate the effect of two types of substrates (natural and artificial) at three densities (10, 20, and 30%), on the growth of coarse scale jaraqui (Semaprochilodus insignis) in monoculture and polyculture with tambaqui (Colossoma macropomum), the latter with the addition of ration. There were conducted two experiments; in the first, the effect of the density and type of substrate on the performance of Jaraqui was tested (10, 20 and 30%), on the latter, the effect of the type of substrates at 20% density was investigated on the performance of jaraqui when cultured with tambaqui. Natural substrate, macrophyte Pistia stratiotes and artificial substrate plastic screen were used. Fish culture was carried out in masonry 46m2 tanks having average depth of 70 cm. The tanks were fertilized with urea, triple superphosphate and bran based on water transparency (30-50 cm). The difference between treatments was assessed using analysis of variance with two and one factors (Two and one-way ANOVA). The two substrates tested in this study provided good surface for periphyton growth; however, macrophyte supported higher periphyton biomass in both the experiments. On the first experiment, jaraqui showed higher growth in ponds where artificial substrate was added at densities of 10% and 20% and natural substrate P. stratiotes at 20%. Based on this result, in the second experiment, 20% density was used for both the substrates. Both jaraqui and tambaqui highest productivity was recorded in the treatments with plastic screen. Jaraqui showed slightly better growth performance with plastic screen as substrate. Tambaqui showed good performance in both treatments. Apparently, tambaqui leverages periphyton as an alternative food ration. Further studies are required to quantify periphyton contribution to the growth of fish and its effect on savings in terms of food ration.