Physiological and oxidative responses of Colossoma macropomum and hybrid ♀ C. macropomum × ♂ Piaractus brachypomus subjected to different stressors in a recirculating aquaculture system (RAS).

Abstract

The effects of acute handling stress on the physiological and antioxidant responses of tambaqui (Colossoma macropomum) and the hybrid tambatinga (C. macropomum × Piaractus brachypomus) raised in a recirculating aquaculture system were investigated. Thirty juveniles of tambaqui (27.8 ± 2.8 g) and thirty of tambatinga (26.2 ± 3.1 g) were used. Six fish/group were captured and subjected to the sample to determine basal parameters. The remaining animals were chased with hand net for 3 minutes, exposed to air for 2 minutes and subjected to biometry. Blood and oxidative parameters were determined immediately after stress (IAE) and after 1h (1hAE), 24h (24hAE) and 48h (48hAE). Stress caused an increase in the hematocrit of tambaqui at IAE, with reduction after 48hAE. For glycemia, there were differences between the fish groups and collections with higher values for tambatinga and after IAE and 1hAE. Cholesterol in tambaqui increased after 24hAE and 48hAE, decreasing in hybrid after 24hAE with return to basal after 48hAE. SOD increased in IAE while in tambaqui the response only occurred after 48hAE, resulting in an increase in lipid peroxidation. Conclude that biometric management resulted in hemodilution in tambatinga, without recovery of basal parameters. However, the antioxidant system prevented lipid peroxidation.