Like their cephalopod cousins the octopuses, cuttlefish are masters of disguise.

As they hunt, these marine predators send waves of color across their skin. The rainbow display stops prey in their tracks, granting the cuttlefish just enough time to shoot out two specialized hunting tentacles at lightning speed and snatch them into range of their deadly beaks.

But can cuttlefish actually mesmerize prey with their colorful skin changes? Or is something fishier at play?

Experts told Live Science that cuttlefish are ingenious hunters, but that there's likely an even more mysterious process than hunter to prey hypnosis going down on the seafloor.

A calculated hunter

Cuttlefish are visual hunters, using their large, complex eyes to locate and track potential meals. In general, their strategy involves a slow, stealthy approach, said Bret Grasse, the manager of cephalopod operations at the Marine Biological Laboratory in Woods Hole Massachusetts.

"The cuttlefish will slowly approach the prey so as to not alert the unsuspecting shrimp, fish or crab," Grasse told Live Science in an email.

During their approach, cuttlefish often put on a showy display, producing moving bands across their body. These displays are produced by a combination of light-reflecting pigment cells known as iridophores, leucophores and chromatophores. These cell types contract and expand to produce specific colors and patterns, all within milliseconds.

Some may wonder whether this trick can mesmerize prey, but scientists don't think that's the case.

Hypnosis, defined as a mental state of increased relaxation and altered awareness, is thought to be a uniquely human psychological state. There is very little research on whether fish can be hypnotized, but a 2005 study found that pushing a steady stream of water through the snapper (Chrysophrys auratus) put them in an immobile state similar to being hypnotized. Another study looked at sedative hypnotic drugs like benzodiazepines and barbiturates and their effects on zebrafish, finding that the fish had molecular receptors for these drugs, which helped render them immobile. However, whether fish can be visually put into a state like hypnosis has yet to be directly studied.

And while some animals, such as chickens, can be induced into trance-like conditions of tonic immobility, an involuntary, temporary state of unresponsiveness that happens when humans or animals experience extreme trauma, it's unlikely that the cuttlefish's color changes "hypnotize" their prey, Connor Gibbons, the cephalopod facility manager at Columbia University told Live Science. Instead, some researchers believe that the color show serves as an ingenious disguise.

As waves of different colors ripple down the cuttlefish's body, the shape of the animal becomes less obvious to its prey, so they may not see the cuttlefish as a threat to flee from, Gibbons said.

"It's only part of something looming at them, which they're like, 'I don't know if you are a predator? Are you just passing waves? What are you?'" Gibbons said. "And then by that time, it's too late."

Once they get close enough, the cuttlefish shoots their two long, specialized feeding tentacles from small hidden pouches near the animal's mouth at their prey.

"The closest thing I can compare it to is the tongue of a chameleon extending out to grab an unsuspecting insect," Grasse said. "Cuttlefish feeding tentacles will fire out in the blink of an eye before the prey can react and escape."

Then, the prey is pulled toward the cuttlefish's mouth, pierced by its sharp, chitinous beak and injected with venom. The use of the venom helps the cuttlefish reduce their energy usage when hunting "as the cuttlefish does not want to use unnecessary energy and struggle against the prey while it's trying to eat," Grasse said.

However, the notion that cuttlefish flash colors to hide their body shape is only one idea of why cuttlefish perform these strobing color displays. Other researchers, including Grasse, describe them as a way to distract their prey.

"Essentially, they are trying their best not to alarm the prey to their presence," he said. By breaking up the size of their bodies, cuttlefish can convince their prey they're not as large or alarming as they may seem.

Whether the light shows are for disguise or distraction still needs parsing out, Gibbons said, and scientists also need a better understanding of how the cuttlefish controls its deadly dermal display. "The jury is still out on exactly what is happening," he said.

How much do you know about octopuses? Find out with our octopus quiz!

A bizarre squid has been filmed haunting the northeastern Pacific Ocean for the first time.

Researchers spotted the bigfin squid (Magnapinna) via remote video while using an uncrewed submersible to explore underwater mountains, known as seamounts, at a depth of more than 10,000 feet (3,000 meters) off the coast of California.

The footage, captured Aug. 7, represents the first confirmed live observation of a bigfin squid in the northeastern Pacific, according to the Monterey Bay Aquarium Research Institute (MBARI), whose scientists made the discovery with collaborators from the National Oceanic and Atmospheric Administration (NOAA).

Olívia Soares Pereira, a deep-sea ecologist and postdoctoral fellow at MBARI, said the squid was hovering over the seafloor with its arms and tentacles bent at a 90-degree angle — what the researchers called the "elbow pose."

"Based on the behavior of other deep-sea squids, we believe this pose could be a part of their feeding tactics," Pereira told Live Science in an email. "The arms and tentacles are extended so they do not get tangled up and passively capture prey that sticks to them."

Bigfin squid are the deepest-dwelling known squid and have been found more than 20,000 feet (6,000 m) below the surface. Most of the animals' total length comes from their tentacles and arms, which can be 20 times longer than their bodies. The individual in the video was about 4.1 feet (1.25 m) long, including body, tentacles and arms, according to MBARI.

The last time MBARI researchers encountered a bigfin squid was off Hawaii in 2001, though around 70 have been observed or collected in total, according to MBARI. Pereira said she saw two other bigfin squid during an expedition to the Mid-Atlantic Ridge — located along the Atlantic Ocean floor — with the Schmidt Ocean Institute earlier this year.

"When we saw this one, I couldn't believe my luck!" she added.

The team was piloting MBARI's Doc Ricketts submersible when they encountered the squid near the Davidson Seamount at a depth of around 10,751 feet (3,277 m), about 80 miles (130 kilometers) southwest of Monterey, during a 10-day Seamount Hotspots expedition between Aug. 3 and Aug. 12.

The researchers were investigating life around the Davidson Seamount and Sur Ridge, which are biodiversity hotspots within the Monterey Bay National Marine Sanctuary, a massive federally protected area off central California. Although these areas are known to be teeming with life, a bigfin squid was not on the list of animals the researchers expected to see.

"We were looking for thriving communities of deep-sea corals and sponges, brooding deep-sea octopus, and feeding beaked whales," Pereira said. "Finding a rare animal that we weren't specifically looking for highlights the incredible diversity and habitat complexity of this region."