Most striper flies imitate baitfish, but there are times the fish want crabs, and that is where the crab fly comes in. When striped bass are rooting green crabs on a flat, or you are chasing structure-loving tautog, a good crab pattern is the difference-maker.
What it imitates
Crab flies, from flats-style Merkin patterns to heavier tog versions, imitate a small crab: a flat, sinking body with legs and claws and enough weight to get down and sit on the bottom the way a real crab would. Green, tan and olive tones match our green crabs.
How to fish it
The key is the sink and the sit. Cast ahead of a cruising, tailing fish, let the crab drop to the bottom, and give it a tiny twitch, a fleeing crab, when the fish closes in. On the flats it is a sight-fishing fly; for tautog it is fished tight to structure. Let it get down and stay down.
Tip Do not overwork a crab fly. Real crabs sit and scuttle, they do not swim steadily, so let the fly sink and rest, then give it the smallest hop when a fish is close. Stripping it like a baitfish looks unnatural to a crab-feeding fish.