Mayfly nymphs from the river Wear

Some yellow May dun mayfly nymphs, from the river Wear downstream from Wolsingham. The upper reaches of the river are full of these, clinging on to the underside of every rock pulled out of the water. They are one of the food items that dippers catch, when they walk underwater, over the river bed, and flip stones with their beaks in search of prey. 

In the image above you can clearly see the feathery abdominal gills, that beat constantly and absorb dissolved oxygen from the water,