EXPOSURE TO N-(1,3IDIMETHYLBUTYL1)

The study investigated the effects of 6PPD-quinone (6PPD-Q) on the swimming performance of Clarias gariepinus fingerlings over a 28-day exposure period. Fish were exposed to nominal concentrations of 0 µg/L 6PPD-Q (positive control), 200 µg/L DMSO (negative control), and 500, 1000, and 1500 µg/L 6PPD-Q. Swimming speed showed a clear concentration and time dependent reduction across all treatment groups compared to the positive control. The mean swimming speeds (m/s) for the respective treatments were 2.115 ± 1.252, 0.8950 ± 0.2758, 0.8050 ± 0.0778, 0.1100 ± 0.0212, and 0.0250 ± 0.0071 on day 7; 4.110 ± 1.725, 0.4750 ± 0.1061, 0.0600 ± 0.0212, 0.0600 ± 0.0212, and 0.0150 ± 0.0071 on day 14; 0.8950 ± 0.2758, 0.6050 ± 0.0778, 0.1350 ± 0.0212, 0.0550 ± 0.0071, and 0.0350 ± 0.0071 on day 21; and 0.5800 ± 0.1838, 0.2500 ± 0.1556, 0.1650 ± 0.0495, and 0.0400 ± 0.0212 on day 28. Statistically significant differences (p <0.05) were observed between all 6PPD-Q-exposed groups and the positive control, except for the 200 µg/L and negative control groups on days 7, 21, and 28 (p > 0.05). Percentage reductions in swimming speed relative to the positive control were 57.7%, 61.9%, 94.8%, and 98.8% on day 7 for the negative control and 500, 1000, and 1500 µg/L groups, respectively. By day 21, reductions reached 32.4%, 84.9%, 93.9%, and 96.1%, and further deepened to 56.9%, 71.6%, 86.2%, and 93.1% by day 28. The observed decline in swimming performance indicates that 6PPD-Q impairs locomotor ability in C. gariepinus in a dose and duration dependent manner, potentially compromising survival and ecological fitness in contaminated aquatic environments