The water is clean enough to support mayfly larvae which have three thin tails and a fringe of gills along either side of the abdomen.
A small 'bloodworm', the larva of a chironomid midge swims with a figure-of-eight motion, like a madly animated piece of vermicelli. The chironomid midge is a non-biting species.
A water mite scurries busily past. It has eight legs but, unlike a spider, its circular body is all in one section.