Lilliput Longarm Octopus

Macrotritopus defilippi, commonly known as the Lilliput longarm octopus or Atlantic longarm octopus, is a small marine cephalopod that dwells in the Atlantic Ocean, the Mediterranean Sea, and certain areas of the 🌊 Indian Ocean, including the coast of 🇸🇴 Somalia. These creatures prefer shallow, sandy environments at depths ranging from 5 to 200 meters (16 to 656 feet). They are small, with a maximum length of 9 cm (3.5 inches) and a weight of 56.4 grams (about 2 ounces).

The octopus is renowned for its incredible camouflage abilities, marked by a yellowish-brown color that helps it blend seamlessly with its surroundings. Its skin can vary in appearance to match sandy or gravelly substrates, and it might develop small papillae and light and dark arm barring. When motionless, it is notoriously difficult to spot, and it can hide completely beneath the sand without leaving a trace.

This species is particularly interesting for its mimicry abilities. In the Caribbean, the octopus mimics the swimming behavior of the plate fish (Bothus lunatus), a local flounder species. The octopus can imitate the flounder’s movement by swimming in a flattened posture with its arms trailing alongside, making it appear less like an octopus and more like the flatfish. This mimicry likely functions as a defense mechanism, deterring predators by resembling a hard-to-swallow flounder.

Like other octopuses, Macrotritopus defilippi is gonochoric, meaning individuals are distinctly male or female. After mating, males die soon after spawning, while females perish after brooding. Males engage in display behaviors to attract females, and during mating, they use a modified arm to transfer sperm to the female's mantle cavity, where fertilization usually happens. The resulting embryos hatch into planktonic larvae before settling on the seabed as adults.

This species was previously recognized just from larvae found in the Caribbean, which showcase notably long third arms. These larvae have an extended-arm posture and can swiftly jet through the water when alarmed. As they mature, they become more adapted to life on the seabed and less active during the night.

Overall, Macrotritopus defilippi's unique adaptations and behaviors illustrate the fascinating survival strategies employed by marine creatures in diverse ocean habitats.