The Veined Octopus or Coconut Octopus is the only invertebrate known to use tools, and one of only two octopuses known to exhibit bipedal behaviour by “walking” on two of its legs.
Coconut octopus in Lembeh © Marco Carnovale
Originally discovered in 1964, Amphioctopus marginatus lives in the tropical waters of the western Pacific Ocean.
The species is commonly known as Veined Octopus, named after the distinct dark brown lines that branch over the mantle and down the arms of the animal. The edges of their arms are often darkened in contrast to the white-blue suckers.
Coconut Octopus © franklin tom
Another common name for these molluscs is Coconut Octopus, which relates to a very peculiar and interesting behaviour of the species: it carries coconut shells and clam shells across the ocean floor and uses them to build fortresses.
Many species of octopuses are known to play with toys or use foreign objects as shelter, but the sophisticated behaviour of the Coconut Octopus is far more complex.
When they find two halves of clam or coconut shells that fit together they bury themselves inside with their strong suckers sealing the shells tightly together, creating the perfect refuge from predators.
But this is not the unusual part of the animals’ behaviour. Scientists are fascinated with the fact that the Coconut Octopus is the first invertebrate known to carry and maintain objects for future use. Interestingly, while the octopuses are transporting the shells, they receive no protection from them.
In fact, they have developed a unique way to carry their gear across the ocean floor in a unique locomotion movement that appears like walking on two of their arms while holding the shells safely in the others. The octopus’ movements seem to be burdened by this technique, yet they will not let go of a perfect pair of shells until a better option crosses their path.
This is how scientists believe the species has evolved from hiding in large empty bivalve mussel shells to seeking shelter in clean and light coconut shells, which are found more recently around the shoreline of busy populated areas.