The muscular thresher shark cuts quite a figure as it navigates through its deepwater domains. Also called the "thrasher shark," this species possesses a distinctive large tail that resembles the arc of a rainbow. The tail is so large that it accounts for 33 percent of the shark's total body weight. Common threshers have a countershaded body, dark blue-gray above and white underneath. It has small jaws, but can use its tail to corral and even kill fish. The first dorsal fin is much, much bigger than the second; the pectoral fins are curved. Like other mackerel sharks, it has an anal fin, 5 gill slits, 2 dorsal fins, no fin spines, mouth behind the eyes, and no nictitating eyelids. It is a very strong swimmer and can even leap out of the water. It is mostly nocturnal (most active at night). Like a giant sea rake, the tail of the thresher shark helps to herd bony fishes and to whack at them, if necessary, before consumption. Usually this shark's hunting technique involves stirring the water around schools of fish, which traps them in a mini whirlpool. The terrified fish huddle together, making them a perfectly concentrated potential meal for the shark. It then zooms into the fish huddle, mouth agape. It also eats squid, bony fishes; stunning the prey with its tail before feeding. The thresher shark can swim at high speeds in short bursts and may even leap high out of the water if threatened or provoked from above. Can reach common maximum depth ofT 1,640 feet