Thaumoctopus

Lore & Background

The mimic octopus was first discovered in 1998 off the coast of Sulawesi, Indonesia, on the bottom of a muddy river mouth. It has since been found throughout the Indo-Pacific, from the Red Sea and Gulf of Oman to New Caledonia, and from the Gulf of Thailand and the Philippines to the Great Barrier Reef, with most documented observations from Indonesia. It primarily inhabits areas with sand or silt at depths of less than 15 m, preferring river mouths and estuaries over reefs.

Appearance-wise, the mimic octopus is a smaller octopus, growing to about 60 cm total length, with arms about the diameter of a pencil at their widest. Small horns protrude from each eye. Its natural color is light brown/beige, but it usually takes on a bold striped white and brown pattern to scare off predators by imitating poisonous species. According to DNA sequence analysis, the second evolved trait was the simultaneous development of its lengthy arms and its flatfish-like swimming ability.

Behaviorally, the mimic octopus uses a jet of water through its funnel to glide over sand while searching for prey, which mostly consists of small fish, crabs, and worms. It has been observed mimicking numerous species, including lionfish, sea snake, jellyfish, and zebra sole. Its mimicry of flatfish may be its preferred guise; a 2008 study showed nearly 500 instances of flatfish mimicry by a single individual over five days. The octopus may intelligently use mimicry based on the situation, such as mimicking a banded sea snake when harassed by damselfish.

Reader's Guide

The mimic octopus stands out from other octopus species because of its extraordinary ability to mimic and imitate a wide variety of species. While most animals that mimic can only mimic a single animal, the mimic octopus can switch between up to 18 different marine disguises, changing not only its color but also its shape and behavior. This ability is used both defensively, to elude predators, and offensively, through aggressive mimicry to approach wary prey—for example, by mimicking a crab as an apparent mate.

Its significance extends to understanding evolved behavior in cephalopods. Mimicry in this species is considered an evolved behavior, and the octopus's large brain—containing roughly 300 million neurons, with each arm having its own neural network—allows for rapid learning, camouflage, memory, and motor control. The mimic octopus and its close relative the wunderpus are the only animals known to actively imitate several different animals to avoid predation, making them unique in the animal kingdom.

The species has been observed in opportunistic mimicry with a jawfish and can also mimic sessile animals such as small sponges, tube worm tubes, or colonial tunicates. While colorblind, their bodies are quite reflective, allowing them to blend in with surroundings like sand, coral, rocks, and algae even when not swimming.

Did You Know?

• It can mimic up to 18 different marine animals, changing color, shape, and behavior.
• The octopus uses aggressive mimicry, such as imitating a crab as a mate, to approach wary prey.