Deep-sea creatures were hatching as scientists found nursery. It may be a new species

A distinctly alien-looking nursery was located atop a sunken mountain off Central America, and scientists arrived just in time to see the tentacles of an unfamiliar species emerging from the eggs.

It was a type of deep sea octopus.

The unnamed outcrop about 100 miles west of Costa Rica has now been deemed one of only three octopus nurseries known to exist, according to the Schmidt Ocean Institute.

“The discovery of a new active octopus nursery over 2,800 meters (1.7 miles) beneath the sea surface ... proves there is still so much to learn about our ocean,” Schmidt Ocean Institute Executive Director Jyotika Virmani said in a news release.

“The deep-sea off Costa Rica rides the edge of human imagination.”

It is believed the site is home to “a new species of Muusoctopus, a genus of small to medium sized octopus without an ink sac,” officials said.

The nursery is small — “about the size of two small cars end to end” — and about a dozen octopuses in the brooding position were seen, according to Beth Orcutt of the U.S.-based Bigelow Laboratory for Ocean Sciences.

“Each brooding mother is typically protecting about a dozen eggs each. During observation of one octopus, we observed the release of at least 10 baby octopus within a few minutes, with a few eggs remaining with embryos still inside,” she said. “There may be other nurseries on this outcrop. However, we were only able to explore a fraction of it during our expedition.”

Two of the world’s three known octopus nurseries are off Costa Rica, she said. The third is the Davidson Seamount off Monterey, California.

The other Costa Rican nursery, (discovered in 2013, is known as the Dorado Outcrop, which covers an area the size of a football field. As many as 100 females have been seen at the site, the institute says.

Both nurseries off Costa Rica are adjacent to low-temperature hydrothermal vents, suggesting the octopus species seeks out such vents for brooding their eggs, officials say.

The institute’s 19-day Octopus Odyssey expedition visited five other “never-before-seen seamounts” in the region to see if they hosted nurseries. The expedition team included 18 international scientists and came back with evidence several new species may have been discovered, officials said.

None of the seamounts they visited are protected as part of marine sanctuaries, officials said.

Costa Rica’s west coast “is home to numerous seamounts,” most in an area where volcanoes sprout from tectonic plate boundaries. However, the Dorado Outcrop is a rare and unusual “off-axis” seamount where hydrothermal vents are cooler due to being farther from the plate boundaries, experts say.

“The low-temperature fluid that emerges on these seamounts is not the result of volcanic activity but comes from the natural cooling of the Earth’s crust,” experts say.

This story was originally published July 3, 2023 at 7:12 AM with the headline "Deep-sea creatures were hatching as scientists found nursery. It may be a new species."