Watercress and Water Quality: The Effect of Phenethyl Isothiocyanate on the Mating Behaviour of Gammarus pulex

Figure 6

The proportion of pairs re-forming after their return to clean water at exposure end. The proportion of pairs re-forming after transfer to clean water at the initial exposure test end is shown for each separate test occasion. The proportion of pairs present at the start of the first exposure was taken as 100%. The mean control re-pairing is shown for comparison, after 24 h in clean water mean of 6 tests (blue line) and after 48 h in clean water mean of 2 tests (green line). Wash water exposures (WW); PEITC exposures (P); proportion of pairs remaining at initial exposure end (red square); after 24h in clean water (green triangle); after 48 h in clean water (blue diamond). NB: Re-pairing was not recorded after test WW1. n denotes the number of tests.