Research Article: 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 (G۱) and three exposures of ۴% (G۲), ۸% (G۳), and ۱۶% (G۴) WSFD. After ۱۶۸ 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 G۱ and the exposure groups (p<۰.۰۵). The mean of WG, SGR, and DGR indices (۷.۰۰ g, ۱.۸۵ %, ۰.۹۹, respectively) in the G۲ had a significant difference with the G۳ (۴.۴۴ g, ۱.۱۲ %, ۰.۶۴, respectively) and the G۴ (۰.۸۹ g, ۰.۲۵ %, ۰.۱۲, respectively) (p<۰.۰۵). In addition, there was a significant difference between growth indices in the G۳ and the G۴ (p<۰.۰۵). There was a significant difference between the mean cortisol and serum glucose levels of the G۱ (۳.۱۸ µg/dl, ۶۱.۳۳ mg/dl) and the G۴ (۱۰.۷۰ µg/dl /ml, ۱۰۸.۳۳ mg/dl) (p<۰.۰۵). Swimming pattern changes, activity level, food intake, and gill movements occurred due to WSFD exposure. The fish behavior was expected in the G۱ and G۲. However, with increasing the concentration of the WSFD to ۱۶%, 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.