Deep Diver

Deep Diver

Marine biologist William Gilly talks about using Crittercam to research the behavior of giant Humboldt squid.


6 - 12+


Earth Science, English Language Arts, Experiential Learning, Geography, Geographic Information Systems (GIS), Human Geography, Physical Geography, Social Studies, Civics, U.S. History

NGS Resource Carousel Loading Logo
Loading ...

Inside the Hopkins Marine Station’s Gilly Lab, Dr. William Gilly stares at black-and-white footage of a Humboldt squid. The new footage was gathered using a Crittercam, a camera designed to be mounted on a wild animal. The clip shows a squid interacting with other members of its species. In the distance, other squid flicker and flash like disorienting strobe lights.

Gilly, a professor at Stanford University, often works out of his lab at the Hopkins Marine Station in Pacific Grove, California. Hopkins is a Stanford-affiliated marine laboratory located about 80 kilometers (50 miles) south of the university’s Palo Alto campus.

In 2009, Gilly and the crew of National Geographic Channel’s Dangerous Encounters With Brady Barrtraveled to the Gulf of California to attach soda-bottle-sized Crittercams to Humboldt squid, which can be up to two meters (six feet) long.

According to Gilly, who has studied the striking cephalopods for more than two decades, the first Crittercam fastened to a Humboldt squid’s body didn’t stay secure for very long. “The squid lasted about two or three minutes,” he says. “Then, all of a sudden, there were 20 or 30 other squid just attacking it. So they ripped the camera off and ripped the whole sleeve that held the camera onto the squid and just tore the whole thing off the squid. Luckily, the whole camera assembly was buoyant, and we ended up getting it back.”

“I guess we learned that squid must be able to sense red light, and it must really piss them off,” he says.

Although that scene must have been dramatic, other Crittercam footage was more interesting to Gilly. This footage showed the giant sea creatures interacting with one another. “We learned about this flickering that goes on,” Gilly says. “We never saw that before. They don’t seem to do that if they are in a tank or something like that.”

“I don’t know what its real role for the squid is,” he says of the flickering. “If it’s doing it when it’s 150 feet [46 meters] deep in the ocean, there’s no patterning of light at those depths. It gets filtered out pretty quickly, but at the surface, it would be useful as camouflage.”

In the future, Gilly hopes Crittercam will help reveal what Humboldt squid do when they are 198 meters (650 feet) below the surface of the ocean, where they spend most of their time. “Are they feeding at depth during daytime?” Gilly asks. “We know they are embedded in a school of food from the sonar. So I just can’t believe they are down there surrounded by their favorite food, and they are just not eating it. It would be nice to show that.”

Gilly also thinks that Crittercam might be able to help scientists uncover whether Humboldt squid use flashing to communicate with one another, possibly while attempting to secure food.

“It would be nice to see about this coordinated hunting stuff,” he says. “If they really do that under different conditions, that would be really interesting because then there may be different signaling to animals going from individual feeding to cooperative feeding. Maybe, they talk about it by flashing or something.”

In addition to Crittercam, Gilly and other marine biologists use sonar, remotely operated underwater vehicles known as ROVs, and tags to research squid. Tags placed on the animals measure depth, temperature, and light in an effort to learn about squid behavior.

“There are good images from MBARI [the Monterey Bay Aquarium Research Institute] from their ROV work where you can see a squid eating different kinds of food,” he says. “They basically have different styles for different things. Lanternfish they sort of pick one at a time with their arms. Bigger fish they come up and shoot their tentacles out and grab it. Things like krill—that are just abundant in a big swarm—they just open their arms up and rake them in like a net.”

Amazing Adaptability

While many other marine populations are plummeting, the Humboldt squid’s numbers actually seem to be growing. Their range, which used to be from Chile to Southern California, has expanded so much that Humboldt squid have been found as far north as the waters off Alaska.

“I think the numbers are going up as well as the range, so I think there are more squid in a bigger area,” Gilly says.

Gilly attributes the Humboldt squid’s recent successes to its adaptability regarding changing water temperatures and oxygen levels in the Pacific Ocean.

“The thing that impresses me most is that no matter what aspect of them you look at they are perfectly designed to be a success,” he says. “Especially in a time of changing climate and climate variability, their adaptability is really amazing.”

Since the Humboldt squid’s presence in the Pacific Ocean is growing, it’s a critical time for Gilly and other marine biologists to learn about this animal with Crittercam and other tools.

“If you were to sit down and design an organism that is a winner as the climate changes, this would be it,” Gilly says. “This is what the top predator will look like.”

Fast Fact

Flicker and Flash
Humboldt squid, which live hundreds of feet below the surface of the ocean, are bioluminescent. They have organs called chromatophores in their skin which change color and reflect light.

Marine biologists only recently learned that Humboldt squid are able to briefly light up their bodies and flicker at each other. The scientists are not quite sure what purpose the flickering serves.

The flickering phenomena is different than Humboldt squid flashing. The flashes happen when a squid turns from white to red. While flashing is a synchronized display, flickering is an ongoing, unpredictable series of dark and light patterns.

Fast Fact

Crafty Carnivore
If you were to sit down and design an organism that is a winner as the climate changes, this would be it. This is what the top predator will look like.
Dr. William Gilly, marine biologist, talking about the Humboldt squid

Fast Fact

Old School
Founded in 1892, Hopkins Marine Station was the first marine laboratory on the west coast of North America. (Only the Marine Biological Laboratory, in Woods Hole, Massachusetts, is older.) Hopkins Marine Station was named after Timothy Hopkins, an early supporter of Stanford University, the school with which the research station is still affiliated.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Stuart Thornton
Jeannie Evers, Emdash Editing, Emdash Editing
Kara West
National Geographic Society
Last Updated

May 20, 2022

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.


If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.


Text on this page is printable and can be used according to our Terms of Service.


Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources