A small cuttlefish of rubble and debris, often hunting alongside a goby.
A small cuttlefish, mantle around 7 cm. The identifying features are large eyes set on two lateral protuberances, short longitudinal skin ridges that can be raised into flaps, a line of small blue spots along the base of the fin, and a light brown to greenish yellow-brown ground colour with white mottling and scattered white spots on the head. Like the flamboyant cuttlefish it walks along the bottom, pulling itself forward on the ventral arm pair together with a pair of raised flaps on the underside of the mantle, and the two are confused for that reason — but this animal never produces the yellow and magenta display or the red arm tips. Against other small regional cuttlefish the blue fin-base spots and the raised eye protuberances are the characters to look for; several congeners are not reliably separable underwater. WoRMS now places it in Ascarosepion, as A. bandense, under the same 2023 revision; Sepia bandensis is the name in general use.
Nocturnal. It frequently associates with sea cucumbers and sea stars, riding or sheltering alongside them. An ambush predator on crustaceans and small fish, camouflaging and then striking with the two feeding tentacles. It breeds from about five months old, mates head to head, and lays clusters of five to forty eggs about a month later; hatchlings are under 6 mm. Life is short even by cephalopod standards, on the order of six months to a year. Much of what is known about its life history comes from the aquarium trade, where it is heavily kept, rather than from the wild.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
