Rare Deep-Sea Squid Captured Camouflaging as Ocean Stalks

Researchers have documented a rare behavior in a deep-sea squid that appears to disguise itself as stalk-like structures on the ocean floor. This discovery was made in the Clarion-Clipperton Zone during a visual survey using a remotely operated vehicle (ROV) in March 2023. The findings were recently published in the journal Ecology.

Uncovering Hidden Behaviors

At a depth of approximately 4,100 meters, the ROV’s cameras initially captured what seemed to be biogenic stalks—organisms resembling glass sponges or tube worms. Moments later, a squid swam rapidly across the camera’s view, surprising the research team who had not detected its presence prior to this footage. Upon closer examination, the team realized the squid had been buried in mud among polymetallic nodules and only emerged just before being recorded.

“The squid only became obvious after it abandoned this behavior and swam away, disturbed by the proximity of the ROV,” the study authors explained. The squid exhibited short arms and elongated white tentacles, measuring about 10 centimeters in mantle length and 22 centimeters in tentacle length. It is believed to be a previously undescribed species from the family Mastigoteuthidae.

Masquerading in the Deep Sea

This behavior, referred to as “masquerading,” may serve a dual purpose: concealing the squid from predators, such as beaked whales, or ambushing prey. By remaining motionless, the squid conserves energy, a strategy that can be more efficient than active hunting. This observation marks the first documented instance of masquerading in a deep-sea cephalopod.

Historically, whiplash squids had been encountered only once in the Northeast Pacific abyss, with a total of only four cephalopods observed in the region since seabed surveying began in the 1970s. The scarcity of sightings has led researchers to believe that their populations are low. However, this recent discovery suggests they may simply be adept at remaining hidden.

The authors emphasize, “As with the number of genetic species, the occurrences and distributions we report here are most certainly an underestimate, since cephalopods can self-disguise as well as sense and potentially avoid underwater sampling vehicles.” Such vehicles have been the primary means of gathering ecological and taxonomic knowledge in the abyssal Pacific.

Understanding the behavior and diversity of deep-sea cephalopods is increasingly important as these ecosystems face threats from climate change and seabed mining. The study highlights the need for more targeted research utilizing unobtrusive camera platforms to explore these habitats further before they are irrevocably altered.

As the abyssal plains encompass more than half of Earth’s surface, this research underscores the vast unknowns that exist within these depths. By enhancing our knowledge of species like cephalopods, scientists can better inform conservation strategies in regions targeted for resource extraction.

This study, authored by Alejandra Mejía-Saenz and colleagues, illustrates the complex life habits of cephalopods in the abyss and signals a need for heightened awareness and research efforts as we navigate the challenges facing our oceans.

The article was written by Krystal Kasal, edited by Gaby Clark, and reviewed by Robert Egan, ensuring adherence to rigorous editorial standards.