Cellulose acetate nanoparticles: impacts of concentration and exposure time on the biochemistry and hematology of juvenile Colossoma macropomum.

This study evaluated the physiological impacts of acute-exposure of tambaqui (Colossoma macropomum) to different concentrations of cellulose acetate nanoparticles at different sampling times. A total of 120 juvenile C. macropomum (38.91 ± 5.57 g and 13.76 ± 0.74 cm in total length) were distributed in 12 tanks of 150 L, in a recirculating aquaculture system (RAS). The juveniles were kept in water containing cellulose acetate nanoparticles (CANs) at four different concentrations (treatments): 0 mg L-¹, 0.01 mg L-¹, 0.10 mg L-¹ and 1.00 mg L-¹. Blood samples were collected after 1 and 24 h of exposure. The juveniles were then relocated to a tank with clean water, where they remained for another 24 h, after which a new blood sample was collected (24 h). Hemoglobin, serum protein and globulin were reduced after 1 h of exposure for the group exposed to 1.00 mg L-¹ of CANs. Glucose levels increased after 24 h for the groups exposed to 0.10 and 1.00 mg L-¹. Urea increased after 1 h for the groups exposed to 0.10 and 1.00 mg L-¹. Triglycerides and cholesterol were reduced both after 1 h and 24 h of exposure for the 1.00 mg L-¹ group, returning to baseline levels at 24 h. The activities of aspartate aminotransferase (AST) and alanine aminotransferase were altered after 24 h. Albumin was lower after 1 h and 24 h compared to after 24 h for the 1.00 mg L-¹ group. Exposure of juvenile C. macropomum to CANs caused transient physiological changes, with partial recovery being observed after transfer to clean water.