Cephalopods
Mimic Octopus
Thaumoctopus mimicus · Cephalopod mollusk — family Octopodidae; described in 2005 after its late-1990s discovery on Indonesian muck
Plenty of octopuses match backgrounds; the mimic octopus impersonates other animals. First noticed on Sulawesi muck in the late 1990s, it forages exposed on bare silt in daylight, and its survival act is a repertoire: flattening into a gliding flounder, trailing banded arms like lionfish spines, or hiding all but two arms in a burrow and waving a convincing banded sea krait. Which impression appears seems to track which predator threatens. Longer lists get claimed — jellyfish, anemones, mantis shrimp — and deserve some skepticism; the core three are well documented. The animal itself is slight, brown-and-white banded, arms like linguine, probing worm holes across featureless slopes. Whole dives at black-sand sites are built around finding one. Stay off the silt, follow at arm's length, and let the show be voluntary.
Where and when to see one
"Resident" means most dives at that destination encounter them; "seasonal" means reliably present in the listed months; anything else is a bonus, not a plan.
| Destination | Reliability | Months | Notes |
|---|---|---|---|
| Bali & Nusa PenidaIndonesia | Occasional | Year-round | |
| Lembeh StraitIndonesia | Occasional | Year-round | |
| AnilaoPhilippines | Occasional | Year-round | |
| Dumaguete, Dauin & Apo IslandPhilippines | Occasional | Year-round | |
| Banda Sea & AmbonIndonesia | Occasional | Year-round |
Best month, at a glance
Understanding them
Habitat: Bare silt and black-sand flats near river mouths and muck bays, foraging around worm holes and burrows it can dive into.
Range: Indo-Malayan region — Indonesia and the Philippines through to northern Australia and New Guinea.
Behavior: Forages exposed in daylight on featureless bottom, switching between impersonations — a gliding flounder, trailing lionfish-like arms, or a banded sea krait waved from a burrow — apparently matched to the threat at hand.
Diet: Small crustaceans and fishes probed out of burrows with linguine-thin arms.
Size: typically around 0.4 m; documented up to 0.6 m (arm-span; the arms are strikingly slender).
How to behave around one
Follow at arm's length off the bottom, never dig, corral, or bait, and let every impersonation be the animal's own idea.
Conservation
Not reliably assessed; its narrow, developable coastal habitat and value to dive tourism argue for keeping muck bays healthy.
Charted sites known for them
Watch
From the official channels
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