Recent research had been done by scientists studying enzyme activity of acetylcholinesterase (AChE) and glutation S-transferase (GST) on waterlice (Asellus aquaticus, Crustacea, Isopoda) collected at different locations in different seasons and recorded ample variability in results. We wanted to find out if light and water temperature have an effect on the observed variability of the tested enzyme activities. Three laboratory experiments were set up, using three different regimes of conditions: 11 ºC and darkness; 11 ºC and day-night cycle (16:8h light:darkness); and 20 ºC and day-night cycle (16:8h light:darkness). The surface population was sampled twice (23. 2. 2016 and 5. 5. 2016) in a swampy forest near the National institute of biology, and we ran one experiment after each sampling day. We sampled the subjects after 1, 2 and 3 weeks in the laboratory. We sampled the cave population in Planina cave once (24. 5. 2017) and ran a lab experiment, sampling our subjects after one and two weeks. We found that the activity of AChE and GST changes differently in the three lab environments. In cave animals subjected to 20 ºC and day-night cycle conditions, AChE activity increases and GST activity decreases. In surface animals the response varies due to the age of the test subjects. In older subjects GST doesn't vary much, but AChE is in some cases higher in comparison to the activities in animals collected in the field. Unexpectedly there was no notable difference between enzyme activity of cave animals and older surface animals, sampled in mid-spring. We didn't manage to explain if the enzyme activity in aquatic isopods varies due to light and/or temperature.