The Amazing Coconut Octopus

The most common octopus species to be found on the black sand sites of Lembeh Strait also happens to be one of the most interesting critters anywhere. The veined octopus, which is more commonly called the coconut octopus, is a firm crowd favourite. It is much larger than the bluering or hairy octopus and less shy than the mimic and wonderpus. Not poisonous, this octopus has developed remarkable building skills which help it to survive, creating portable fortifications that can be opened and closed using their powerful arms and suckers.

They are often found using discarded coconut shells as a home base, but will use whatever is at hand, including shells and bottles along with bits of plastic or wood. The home can be buried in the sand or sitting right out in the open. Once large enough, this clever species will even carry their mobile home with them as they move in order to find acceptable hunting grounds, with crabs being the preferred prey.

Like all octopus, the coconut octopus is curious and aggressive. They normally leave their home to hunt, often as far away as twenty meters, retreating to shelter if threatened. They can dig into the sand if necessary and often seek shelter on the prowl, so are not always found in a protective structure. I sometimes offer shells and watch as this intelligent critter tries out the new shelter, often leaving their existing home, or parts of it, for the upgrade.

Also like any octopus, the veined octopus can change colour and texture as well as mimic other creatures. The best bit of mimicry I have ever witnessed happened to be by one of this species, rather than the mimic octopus, which seems to have a better publicist. I came across one doing an excellent impression of a hermit crab, walking on arm tips, with the body copying an off-center shell of the type often used by bona fide hermit crabs. Once I was less than a meter away and still approaching with interest, it decided that the mimicry wasn’t working and abandoned that shape for the shapeless lump that this species often uses when out in the open; not offering any extending bit that may be bitten off by a passing opportunistic predator.

This fascinating cephalopod can be found throughout the year, day and night, but certain times seem to bring higher densities, where we not only see them every muck dive, but can find ten or more on a single jump at certain sites. When is the best time to see the coconut octo? It can vary, but October is always a good month for sightings and in 2020 they were seen in high numbers in early February, which was a bit odd.