The Frilly Arrow Crab, Stenorhynchus seticornis, also known as the Decorator Arrow Crab, is a long-legged spider-like invertebrate that has small branch-like frills extending from its limbs. They can grow quite large, given the size of their limbs, to a maximum diameter of 10 inches, but usually grow mature to about 7 inches. Interestingly, the Frilly Arrow Crab augments its camouflage by attaching algae and other things found in the tank to its body. The Frilly Arrow Crab likes tanks with spacious live rock openings allowing it space to hide. They are hardy invertebrates but have been known to nip at some crustaceans and smaller, less mobile, fish. The Frilly Arrow Crab accepts most prepared aquarium foods as a supplement to their scavenger feeding habits. Overall, the Frilly Arrow Crab is a stunningly unique addition to any reef tank and is a hardy invertebrate that will add to any reef tank.