Mayfly nymphs are prominent insects in freshwater ecosystems worldwide and an important food source for fish, amphibians, birds and mammals. Unfortunately they are also very sensitive to pollution.Researchers in the Faculty of Science have been interested in better understanding why mayfly nymphs are so vulnerable to environmental insult. They believe that the answer lies in the insects’ gills, which help them acquire oxygen from the surrounding water. But little is known about the physiology of these organs.