York science student’s research ends 50-year speculation on mayfly biology

 Mayfly nymph, dorsal view, showing wing buds, 7 pairs of gills and 3 abdominal appendages

Above: A Mayfly nymph, dorsal view, showing wing buds, seven pairs of gills and three abdominal appendages

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.

During her undergraduate thesis, Faculty of Science student Fargol Nowghani wanted to learn more about the role of the gills in salt uptake. For almost 50 years, scientists have speculated that the nymph’s gills help the insect acquire salt from the water, but until now, there has been no direct evidence to support this view.

Nowghani has now answered this age old question in a paper published in the Journal of Experimental Biology.

Mentored by PhD student Sima Jonusaite (now a postdoctoral fellow at the University of Utah) and working under the supervision of Biology Professors Andrew Donini and Scott Kelly in the Faculty of Science, Nowghani used the latest technology to measure ion transport across gills in real time. She was able to show that sodium in the surrounding water is transported by the gills into the blood of the nymphs, providing the first direct evidence that the gills are ion transport organs. She received the AGSBS Dean’s Honours Thesis Award for this work. The research was also done in collaboration with Trudy Watson-Leung at the Ontario Ministry of the Environment and Climate Change.

“We are very proud of the achievements of our students, and for an undergraduate to publish her work in one of the most cited journals in biology is truly outstanding,” said Kelly.

The research demonstrates that gills play a critical role in mayfly nymphs’ ability to survive in freshwater. Fargol has now started her MSc studies in the Faculty of Science and is examining how environmental change impacts the function of the mayfly gill.

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