Coconut octopus

Amphioctopus marginatus

Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Octopodidae
Genus: Amphioctopus
Species: Amphioctopus marginatus

The coconut octopus (Amphioctopus marginatus) is a small, clever octopus famous for carrying coconut shells and clam shells across the sand to use as a portable shelter. It is one of the few invertebrates known to use tools, and watching one stack two shell halves under its body and 'stilt-walk' away is a highlight of any muck dive.

Its mantle is usually only around 8 cm long, with an arm span of roughly 15 cm. It is typically brown to beige with darker veining, pale suckers and a distinctive dark, mottled pattern, and like other octopuses it can change colour and skin texture in an instant. It feeds mainly on small crabs, shrimp and clams.

Coconut octopuses live on sandy and silty bottoms across the tropical Indo-Pacific and are a regular find on black sand slopes in the Philippines, where discarded coconut shells and bottles make perfect homes. They are most active around dusk and on night dives.