Few flies effectively imitate the shape and movement of the Isonychia nymph. The Isonychia, aka the Slate Drake, nymph is a fast and strong swimmer so the nymph is best fished with a wet fly swing or like a small streamer. This pattern uses materials that imitate the fast movements of the natural so that even at rest the body appears to be moving. When not at rest on the stream bottom the natural nymph is in near constant motion.