Wunderpus

Smaller than it looks in photographs: the mantle reaches about 3.6 cm and the whole animal about 23 cm, against roughly half a metre for the mimic octopus. The arms are long and slender and the eyes sit on elongated stalks. The ground colour is rusty brown to brownish-red, carrying white spots and bands with sharp, clean edges, including a ring of about six white spots around the rear lip of the mantle. The suckers are yellowish-cream. Against the mimic octopus: no white V on the rear mantle, no white line along the sucker bases, crisper pattern edges, longer eye stalks, and one or two reddish-brown patches that pulse between the eyes. Size is a useful backstop, since the mimic is about twice as large.

The white markings on the mantle are individually unique and hold their arrangement for at least ten weeks, which means an animal can be identified from a photograph — volunteers matched images of the same individual with about 82 per cent accuracy. For a site returning to the same slopes year after year that is worth knowing: your pictures can tell you whether it is the same animal. It is crepuscular, coming out of the burrow in the half-light at dusk and dawn and often occupying the same burrow for a long stretch. It forages two ways, probing its arms into crevices and parachuting the web over a patch of sediment to trap whatever is under it. Solitary. Females lay around two thousand small stalked eggs and die once they hatch. Density is extremely patchy — nothing for months, then as many as five animals in a 25 m² patch. The mimicry sometimes attributed to it appears to be borrowed from its sister species; the phylogenetic work that looked at mimicry in this group attributes none to this animal.