Fig. 1. Time course of inhibition and recovery of cholinesterase (ChE) activity in Chilina gibbosa after two days of exposure to 20 g L−1 azinphos-methyl (AZM). ChE activity
was expressed as% of control activity. Control values of ChEs correspond to 0.058 ± 0.005 moles min−1 mg protein−1. Organisms were exposed for 48 h and then transferred
to clean water for 21 days. Boundary of boxes closest to zero indicates 25th percentile, full line within boxes marks median while broken line represents mean, and boundary
of boxes furthest from zero indicates 75th percentile. Statistical differences are indicated with different letters.