Desempenho produtivo de matrinxã (Brycon amazonicus) e tambaqui (Colossoma macropomum) submetidos a baixa salinidade em sistema BFT

Abstract

Traditional fish production systems, in particular systems that using ponds, have limitations with respect to production volumes per unit area, the amount of water required and the spaces where they can be installed, once the world demand increases for food and environmental control, the fish sector will have to incorporate new technologies that generate a better efficiency in the production of aquatic organisms. Searching increase efficiency in the use of area and other natural resources, some types of aquaculture systems were developed, such as the BFT system (acronym in English for biofloc technology), which is based on the activity of the microbial community of an aquaculture tank for carrying out water treatment in situ. Therefore, the general objective of this Thesis of Doctorate was to evaluate the productive performance of matrinxã and tambaqui submitted to the BFT system under low salinity. The methodologies employed allowed two experimental periods to be carried out: the first experiment evaluated the zootechnical performance and the hematological parameters of the tambaqui created in BFT system, according to four different levels of salinity: (T1) = 0‰; (T2) = 2‰; (T3) = 4‰; (T4) = 6‰; the second experiment analyzed the zootechnical performance and the hematological parameters of matrinxã and tambaqui submitted to two different feeding frequencies in BFT system under low salinity: (C. macropomum 6/7) = feeding every day, except on Sundays; (C. macropomum 5/7) = feeding every day, except on Sundays and Wednesdays; (B. amazonicus 6/7) = feeding every day, except on Sundays; (B. amazonicus 5/7) = feeding every day, except on Sundays and Wednesdays. The other two articles were written based on the scientific experiments carried out, and article 03 analyzed technical and economic aspects of culture of tambaqui in BFT system with low salinity, comparing with the viability of this type of culture with traditional systems for producing tambaqui applied in three different states of the Brazilian Amazon. In general, zootechnical performance did not show statistically differences for any of the tested treatments (p>0,05), however the results achieved by tambaqui in salinity 4‰, mainly related to SGR (specific growth rate in %) and FCR (feed conversion ratio), indicate this salinity as the most suitable for the cultivation of this species. The hematological parameters, with some exceptions, remained within the established standard for matrinxã and tambaqui in aquaculture conditions. The feeding frequency tested did not shown statistics differences among the treatments. So is indicated the salinity of 4‰ and the supply of food for five days per seven days during the culture of tambaqui and matrinxã in intensive BFT systems. For commercial culture, the use of BFT system for production of tambaqui is only indicated together with the installation of an on-grid electrical system for power generation through photovoltaic panels.