Rare Deep-Sea Squid Tricks Predators by Hiding Its Head in Mud

A Hidden Master of Disguise

Hiding deep in the Pacific Ocean, a rarely seen cephalopod may be one of nature's most cunning masters of disguise. In March 2023, an underwater rover captured footage of this squid while it was traversing the seafloor at a depth of around 13,500 feet (4,100 meters). Just moments before, however, it was engaged in a peculiar disappearing act.

In a recent study published in Ecology, researchers described how this undescribed species of whiplash squid appeared to emerge from nowhere. Upon reviewing the video footage, they noticed that the squid had been buried under mud, with its tentacles rising from the seafloor. While it's unclear what the squid was doing with its head in the ground, this behavior might have been an attempt to avoid predators or a clever ruse to lure unsuspecting prey.

A Discovery in the Ocean Abyss

The footage of the squid was taken in an abyssal plain, a region located between 10,000 and 20,000 feet deep. This area is one of the least explored parts of the Earth, making it a challenging environment for scientific research. Abyssal cephalopods and other marine life are not easy to observe due to their low abundance and avoidance behaviors, which have made it difficult for scientists to fully understand the biodiversity of these depths.

The researchers conducting the new study were performing visual surveys in the eastern Clarion-Clipperton Zone (CCZ), a section of the Pacific abyssal plains that has attracted attention for potential deep-sea mining activities. A remotely operated rover equipped with multiple cameras was moving along the seafloor when it encountered the squid. The squid’s mantle, or main body, was nearly 4 inches long, and its bright white tentacles extended to about 8 inches in length.

Based on its size, wide elliptical fins, and relatively short arms, the researchers believe the squid likely belongs to the Mastigoteuthidae family, also known as whiplash squids. Only one other squid of the same potential species had previously been observed in the CCZ.

Hiding in Plain Sight

The rover's footage revealed that the squid was initially buried under mud, positioned upside down with both of its tentacles extending upward. But what was it trying to achieve in this situation?

Whiplash squids have been observed in a "tuning fork" posture, where they hover over the seafloor with their heads down and their tentacles spread apart to catch slow-moving prey, similar to fly paper. However, the behavior documented in the study appears to be entirely different.

Some cephalopods, like octopuses, are known to bury themselves using their arms as shovels, while cuttlefish pump water to scatter the seafloor substrate and cover themselves with falling particles. In the case of the whiplash squid, the researchers have proposed two theories involving masquerading behavior.

One theory suggests that the squid may have been disguising itself as a stalk-like organism, such as glass sponges or tube worms, to avoid predators like beaked whales or other cephalopods. Alternatively, the squid could have been pretending to be a harmless structure to attract and capture seafloor prey like crustaceans, which often visit sponge stalks and coral colonies—areas known for high biodiversity in the ocean abyss.

Elusive Squids

Whether the squid was hiding from predators or waiting to catch prey, this behavior may help explain why squids are so difficult to find on the abyssal plains. The researchers emphasize that cephalopods play a crucial role in benthopelagic trophic food webs, acting as both predators and prey for larger apex predators.

"The need for further investigations targeting cephalopods, such as the use of camera platforms, is urgent to protect the functional complexity and biodiversity of the abyssal Pacific seabed," the researchers concluded.