Astronesthes richardsoni chin is ribbon-like and lacks a bulb or swelling at its tip. The dorsal fin has 12 to 14 soft rays and the anal fin has 13 to 18. The origin of the dorsal fin is behind the insertion of the pelvic fins. There is a dorsal adipose fin anterior to the caudal peduncle, and a small ventral adipose fin just anterior to the anus. There are two rows of photophores (luminous spots) on each side of the underside of the fish, numerous other photophores on the head and body and a luminous patch on the edge of the preoperculum;
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