The effects of the water-soluble fraction of diesel (WSFD) on behavioral, biochemical, and growth response in common carp (Cyprinus carpio)

This study investigated the effect of the water-soluble fraction of diesel (WSFD) on common carp behavioral, biochemical, and growth responses. Fish were divided into four groups, including control group (G1) and three exposures of 4% (G2), 8% (G3), and 16% (G4) WSFD. After 168 hours, weight gain (WG), specific growth rate (SGR), and daily growth rate (DGR) were calculated, and blood samples were taken. The results showed a significant difference between the growth indices of the G1 and the exposure groups (p<0.05). The mean of WG, SGR, and DGR indices (7.00 g, 1.85 %, 0.99, respectively) in the G2 had a significant difference with the G3 (4.44 g, 1.12 %, 0.64, respectively) and the G4 (0.89 g, 0.25 %, 0.12, respectively) (p<0.05). In addition, there was a significant difference between growth indices in the G3 and the G4 (p<0.05). There was a significant difference between the mean cortisol and serum glucose levels of the G1 (3.18 µg/dl, 61.33 mg/dl) and the G4 (10.70 µg/dl /ml, 108.33 mg/dl) (p<0.05). Swimming pattern changes, activity level, food intake, and gill movements occurred due to WSFD exposure. The fish behavior was expected in the G1 and G2. However, with increasing the concentration of the WSFD to 16%, an imbalance was observed with swimming changes, loss of appetite, decreased mobility, and impaired breathing. The present study's findings showed that WSFD exposure causes growth retardation, disturbance of biochemical blood factors, and behavioral changes in fish.