Biological effects of pyrimethinal on aquatic worms (Tubifex tubifex)‎ under laboratory conditions

الملخص EN

Laboratory studies were conducted to determine the effects of different concentrations of pyrimethinal (5, 10, 15, 20 and 25 mg / l) on protein content, and some oxidative stress parameters in an aquatic worm, tubbier tubbier after 2, 4, and 7 days of exposure.

In addition, residues of the fungicide were quantified in water and in the worms.

In water, pyrimethinal concentration decreased slowly (maximum – 6.4 ± 0.8 % after 2 days for 25 mg / l).

In the worms, it increased after 4 days and decreased thereafter, confirming that the worms were exposed to the fungicide and not to a degradation product.

LC50 values of pyrimethinal were between 49.2 ± 0.58 and 39.5 ± 0.95 mg / l depending on exposure time.

All the measured parameters appeared to be more sensitive than mortality.

The activity of catalase (CAT) increased in response to the fungicide after 2 days of exposure to 25 mg / l of pyrimethinal (+84.95 %), demonstrating an oxidative stress in the worms.

In contrast GST activity decreased, this decrease was significant for all fungicide concentrations after two days.

The highest DECREASE of GST activity (- 29.7 %) was found after 7 days in the presence of 25 mg / l of pyrimethinal.