Invertebrate nymphs in the Wye and Backstream

Our Riverfly Monitors are pleased to share these short videos of Caddis and Mayfly nymphs.

These cased Caddisfly (Limnephilidae) were netted during riverfly sampling in the River Wye at Kingsmead near High Wycombe in January 2022. This family may build their cases from sand or sticks in the river.
Cased Caddisfly nymphs (Limnephilidae) – YouTube

These mayfly were caught during a river fly count in Backstream (a tributary of the R. Wye) at Beech Road ford near High Wycombe in February 2022. They are one of the largest mayfly, inhabiting the sediment in flowing rivers, and are an attractive food for fish. Note the feather-like gills which is characteristic of this family. They remain as nymphs for at least 1 year.
Large mayfly nymphs (Ephemera) – YouTube