DESEMPENHO PRODUTIVO DO HÍBRIDO PINTADO AMAZÔNICO NA FASE INICIAL DE PRODUÇÃO EM TECNOLOGIA DE BIOFLOCOS (BFT)

Abstract

Aquaculture, a sector that has been steadily growing in recent years, is a significant source of animal-origin protein for human consumption. However, there are challenges to be addressed as the production currently focuses on a limited number of species and lacks technologies in production systems that can enhance the cultivation of South American Neotropical species. The present study evaluated the zootechnical performance of Pintado amazônico juveniles (female Pseudoplatystoma spp x male Leiarius marmoratus) across two culturing systems: biofloc technology (BFT) system and a recirculating aquaculture system (RAS). The study had a completely randomized design with two treatments and four replicates. Each replicate had a volume of 1000 liters and received 250 fingerlings (weight ± dp). The fish were fed to apparent satiation three times daily (8:00, 13:00, and 18:00), with their feeding program divided into two stages over 28 days: (i) From Day 1 to Day 7 they had micro-extruded rations (3 mm, and 60% crude protein), and (ii) extruded feed (0.8–1.5 mm and 45% crude protein) from Day 8-28. The bioflocs collected in the BFT comprise approximately 36.86% crude protein, 1.38% lipids and 34.30% ash. The RAS and BFT production systems showed similar water quality variables, although there were higher concentrations of nitrate and orthophosphate in the BFT. The standard length of fish produced in the BFT system was greater (P<0,05) than those produced in the RAS from 14 days of production, while the weight of the fish produced by BFT was greater(P<0,05) than the RAS fish in all evaluation periods (7, 14, 21 and 28 days). However, survival rates were greater (P<0,05) in fish produced in the RAS compared with those produced in the BFT. There were no significant differences in final biomass, biomass gain, feed conversion ratio, hepatosomatic index and viscerosomatic index between BFT and RAS. Fish produced in BFT had higher (P<0,05) dry matter composition, lipid levels and ash content, while RAS had higher (P<0,05) crude protein content. Regarding intestinal morphology, there were no significant differences in the mean diameter of the tube, height, and mean width of villi, or in the mean thickness of the mucosa and submucosa between the fish produced in BFT and RAS. The current study revealed that the BFT technique is suitable for larviculture of the Pintado amazônico, with the fish showing better growth and weight gain compared with the RAS system. These results underscore the importance of research to identify the best BFT maintenance practices, with a view to improving the survival of the Pintado amazônico.