Giant group of octopus 'moms' discovered during deep sea expedition: 'It's suicide'

A group of more than 100 octopus "moms" and their eggs were found clustered about 2 miles below the ocean's surface off the Pacific coast of Costa Rica. (REUTERS/Jon Nazca)

A group of more than 100 octopus "moms" and their eggs were found clustered about 2 miles below the ocean's surface off the Pacific coast of Costa Rica by a group of scientists during a deep-sea expedition.

The researchers made the surprising discovery while exploring the Dorado Outcrop, a rocky area of the ocean floor created by an underwater volcano, with a drone.

“When I first saw the photos, I was like ‘No, they shouldn’t be there! Not that deep and not that many of them,” Janet Voight, associate curator of zoology at Chicago's Field Museum and an author of a new study on the findings published in "Deep Sea Research Part I," said in a statement online.

The pink, "dinner-plate-sized" octopuses — a never-before-seen species of the genus Muusoctopus — were gathering around cracks in the outcrop, where warm liquids are released. The fact the octopuses were drawn to warmer temperatures shocked Voight, who has been studying the cold water creatures for years.

"It doesn’t make sense for deep-sea octopuses to brood eggs in warm water like this: it’s suicide."

— Janet Voight,

"It doesn’t make sense for deep-sea octopuses to brood eggs in warm water like this: it’s suicide," the Field Museum explained in a post on its website. "Exposure to higher temperatures jump-starts their metabolism, making them need more oxygen than the warm water can provide."

Scientists counted at least 186 eggs attached to the rocky surface, though none had "any sign of developing an embryo."

"All in all, not a great place to start an octopus family," the Field Museum commented.

But there is light at the end of the tunnel, Voight says. The sheer number of octopuses discovered in the area indicates there may be a climate nearby suitable for the "monsters of the sea."

“Octopus females only produce one clutch of eggs in their lives. In order for this huge population to be sustained, there must be even more octopuses to replace the dying mothers and eggs that we can see,” Voight said.

"All in all, not a great place to start an octopus family."

— Field Museum

Voight, along with fellow authors and researchers Geoff Wheat and Anne Hartwell, shared footage of the octopuses with deep-sea biologists. They hope to continue studying and learning from the odd behavior — and maybe even make more startling discoveries.

“The focus of [our] expeditions to Dorado Outcrop was to study a cool hydrothermal system. In doing so, we discovered this fascinating congregation of brooding octopuses,” Wheat, a geochemist at the University of Alaska Fairbanks, said in a statement. “This is only the third hydrothermal system of its type that has been sampled, yet millions of similar environments exist in the deep sea. What other remarkable discoveries are waiting for us?”