Understanding insect life cycles is a core concept in most freshwater fly fishing. It’s hard to find an introductory book that doesn't discuss the development of mayflies, caddisflies, and stoneflies. But what about all the other common creatures that live in rivers? Let’s take a look at some important life cycle details for sculpins, whitefish, suckers, minnows, crayfish, and several other animals that frequent a typical trout stream. We compiled the basics, fly recommendations, and stick around to the end where we conclude with some take-homes for the streamer angler.