A tiny sand octopus, 9 cm (3.5 in) at most, with arms several times the length of a body that is barely bigger than a thumbnail. It is sand-colored, raises small skin papillae to break its outline, and can vanish under the surface without leaving a mark on it. Motionless, it is effectively invisible.
Moving is the problem, because an octopus crossing open sand is worth eating. This one solves it by not looking like an octopus at all: it flattens its body, sweeps all eight arms back into a single trailing outline, and swims in short glides just above the bottom, exactly reproducing the shape, speed and stop-start rhythm of a small flounder. Sand-dwelling flatfish are ignored by many predators that would take a soft-bodied mollusc instantly.
The imitation extends to the details: it holds the same low profile, launches at the same angle and settles the same way. Video comparisons of the octopus and the flounder swimming side by side are the reason this behavior is accepted as true mimicry rather than a coincidence of body shape.
It eats small crustaceans taken from the sand, is active mainly at night, and is one of the animals that makes a slow muck dive over featureless bottom worth doing.
- sand-colored and barely 9 cm, arms several times the body length
- raises small skin papillae and vanishes against sand
- swims flattened with all arms swept back, gliding like a small flounder
- on open sand away from reef
Why it's threatened
The threats to this species are unknown.
Threat classification from the IUCN Red List.
