First-ever colossal squid captured on video | What scientists say it reveals

A colossal squid was filmed in its natural environment by scientists for the first time since its identification and naming 100 years ago, according to the Schmidt Ocean Institute.

"This is a once-in-a-lifetime situation; these types of discoveries don't come along very often," Michelle Taylor, the expedition's chief scientist and professor at the University of Essex, told ABC News.

The sighting occurred on March 9 during a 35-day expedition searching for new marine life in the waters off the South Sandwich Islands in the Atlantic Ocean, the institute said in a press release shared on Tuesday.

The footage, captured by a remotely operated vehicle from the institute, reveals a juvenile colossal squid, nearly one foot long with a see-through appearance, at a depth of almost 1,100 feet, the institute said.

This marked the first time a colossal squid was spotted in its natural environment alive, with previous occasions occurring when it was caught or brought to the surface by fishermen, Taylor said

"It's very challenging to understand the biology, ecology and the behavior of an animal if you've only ever seen dead specimens or on the surface, not in the mid-water area, which is a natural home," Taylor said. "You get a real feel for its behavior and how it moves around its natural environment."

At first, Taylor and her team did not realize this "beautiful, glassy squid" could be a colossal, since they did not have an expert on board. They did not suspect it was this creature until someone watching a livestream of the footage commented, "Is that a juvenile colossal squid?"

"When we first watched it live, it was so beautiful, so we were already quite mesmerized by this stunning little squid. Then to find out that it was something so special, that was a real beautiful moment," Taylor told ABC News.

A traditional colossal squid, also known as Mesonychoteuthis hamiltoni, is estimated to grow up to 23 feet in length and can weigh as much as 1,100 pounds, "making them the heaviest invertebrate on the planet," the institute said.

Despite a giant squid being the longest invertebrate, the colossal squid is the "beefiest," Taylor said.

One of the most distinguishing characteristics of the squid is the "presence of hooks on the middle of their eight arms," the institute said.

The Schmidt Ocean Institute has captured the first confirmed footage of "at least four squid species in the wild," including the Ram's Horn Squid in 2020 and the Promachoteuthis in 2024, with "one more first sighting yet to be confirmed," the institute said.

"These unforgettable moments continue to remind us that the Ocean is brimming with mysteries yet to be solved," said Jyotika Virmani, the Schmidt Ocean Institute executive director.

Taylor said she hopes viewers of the squid footage recognize the "wonder of our planet," specifically the ocean.

"People want to go into space and we have all this beautiful, uncharted territory on our own planet," Taylor said. "There are still so many amazing, incredible things left to discover; we've only scratched the surface."