Cultivo do peixe ornamental molinésia como alternativa para o uso de esgoto tratado na piscicultura

Abstract

The present work evaluated the sustainability of treated sewage reuse in the creation of ornamental molly fish, evaluating the zootechnical performance, ability to adapt to the environment and economic aspects. Three treatments were tested: ET – supplied with treated sewage; ED – supplied with sewage and raw water in the same proportion; AB – supplied with raw water. The physical-chemical results indicated that the treated sewage from stabilization ponds were adequate for the species cultivation only when diluted in raw water. The treatments that were supplied with treated sewage contained the same classes of microalgae present in the maturation pond: Chlorophyceas, Cianophyceas, Bacillariophyceas, Zignemaphyceas e Euglenophyceas; the first four classes are known to be used as feed in aquaculture. Treatment that used treated sewage diluted presented the best results in terms of zootechnical parameters. Amongst the well-being indicators, only histopathological evaluation was able to provide conclusive results, which showed that the treated sewage diluted treatment was the best in terms of comfort to the cultivated species. The ornamental characteristics of farmed fish were not influenced by the use of treated sewage, in which the patterns of color and shape of fins were not changed. The sustainability and economic evaluations also indicated the treatment with diluted treated sewage as the most appropriate treatment.