Nymph

A nymph resembles an insect or stage of insect living underwater. Leeches, mayfly nymphs, caddis fly larva, and diptera can all be imitated by nymphs.

Normally a nymph is tied on a heavier hook, sometimes with an added weight in the body or head to keep it underwater during presentation.

Nymph technique

Nymphs can be fished successfully upstream or down. A large percentage of what fish eat is found living underwater and imitated by nymphs. Without the benefit of seeing the fly, the flyfisherman must distinguish a fish's take from the normal tug of river current. Many nymph fishermen rely on small bobbers, brightly-colored yarn, or other strike indicators to determine when a fish has taken the nymph.