Banded kokopu the dorsal and anal fins are positioned close to the tail fin, which is short and square. The caudal peduncle is short and deep, with thick fleshy flanges which join the tail fin. Adults are usually a dark, earthy brown or olive brown, with pale yellow vertical bands along the body. The belly is light coloured and unpatterned. Behind the operculum and above the pectoral fin is a silver or white mark, and sometimes a darker mark behind this. The bands either fade out top and bottom, or fork and crisscross the back of the fish. In small fish the
Caudal luring are a number of other behavioural interpretations for a wiggling appendage, and luring-like motions are associated with several other behavioural contexts (e.g., defence, stress, etc.). Caudal luring is thought to have evolved from a caudally localised intention movement (a behaviour derived from locomotor movements). Essentially, the act of remaining stationary while sensing prey produces general nervous system excitation that gets released in the form of tail movements. Caudal luring is not merely tail undulations, but must specifically be attractive to prey. Caudal distraction is another behaviour used by snakes, and the tail motions are very similar to caudal luring. The