What crabs see before they are eaten by crabkai

In May 2023, Matteo Sandton was photographing squid on shallow water coral reefs around Indonesia. The marine visual ecologist at the University of Bristol in the UK planned to document the predator's approach to hunting from the perspective of prey. Essentially, it's about seeing what it's like to be a crab.

He wanted to see certain hypnotic camouflages displaying their use of squid during attack. However, this crown had an innovation that showed its own innovation.

“When I first saw these hunting displays, it was probably one of the coolest things I've ever seen,” Dr. Sandton said.

In a series of dives next year, he and his team filmed over 200 squid hunts from the crab-eyed view. In a study published last month in the journal Ecology, scientists documented four elaborate body patterns of squid used, including what appears to be a leaf or coral mimic. Squid displays may somehow hack the visual system of their prey. It may hide their movements or convince the crabs that they are harmless flora and fauna.

Squid is a master of deception. Just like octopus cousins, animals have skin filled with pigment-filled cells and piston-like muscle pumps. They can camouflage almost instantly to hide from predators, for example, blend into the seabed, or disguise rocks and algae. At the laboratory, scientists observe some of these sophisticated behaviors as squid hunts. However, this hunting ability is rarely studied in the wild.

Using GoPro cameras, plexiglass plates and live crabs, researchers photographed broadclub squid around the islands of Kri and Mansuar in eastern Indonesia. In all cases, within a few feet of crab, the squid took one of the four forms described in the study, using names that evoke combat skills.

In one form, as it passes through the stripes, the squid turns gray, passing a rhythmic black stripe through its body. Researchers may be a threatless move to hide the looming presence.

With leaves, the squid becomes pale green, twisting slowly, resembling mangrove leaves that float on the water column.

During the coral branching, they adopt a coral pattern, raising their arms and creating a similar appearance to Stagone's coral.

For pulse techniques, the squid pulls its arm up and into the cone, pulsing a black wave towards the tip. This could mimic anything that is not threatening, such as small fish, researchers suggest.

Trevor Wardill, a sensory neurobiologist at the University of Minnesota, said the pattern movements “give more time to squid as we get closer.” He added that he wonders “how did you build such a system so that even young animals can do this?”

Squid used the branching coral technique more frequently than 12% when hunting purple mangrove crabs. This suggests that you may be adjusting the display to certain prey.

“The fundamental question is how innate responses these are, or whether we can flexibly mix the different components of our behavior and learn about different situations.

Sometimes the squid quickly switched his disguise. In other words, they are tactical cephalopods used to block predators. They must expose themselves as squids have to move into hunting, Dr. Osorio said, and the display may be the same to confuse predators with their prey.

Rachel Brother, professor of neuroscience, cognition and behavior at the University of San Diego, said: “It represents a very sophisticated level of motor coordination.”

Findings also suggest that squids have a larger display repertoire than those studied in the lab. Perhaps the captured squid didn't feel the need to hoodwink food that was already dead, Dr. Sandton said.

Or perhaps they're a bit boring.

“I'm always in the wild,” he said. “And I think animals should be seen in the wild.”