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The operculate (Operculate: Lidlike; usually used to describe the pair of enlarged elytroid gills (called the operculum) which some silt-dwelling mayfly nymphs like Caenis and Eurylophella have developed to shield their other gills from debris.) gills of a Caenis nymph.
Troutnut.com is a collection of pictures and information about fly fishing. Fly fishermen, fly tiers, and trout enthusiasts of all stripes can learn more about life beneath the surface of trout streams, as well as how to better imitate aquatic insects with artificial flies to catch trout. There are aquatic insect pictures, underwater pictures, landscape pictures, and a comprehensive reference to the common names of trout stream insects.
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