Newly discovered sea creatures had to be ‘burped’ to get back home, researcher says

Although its name and likeness are ubiquitous, very little is actually known about the nautilus, a sea creature distinguished by its hallmark spiral-shaped shell.

However, three new species of nautilus have been discovered near a cluster of islands in the Pacific Ocean, shedding light on the enigmatic creature’s evolution and habitat, according to a study published on Jan. 25 in the peer-reviewed journal ZooKeys.

“Nautiluses are seemingly everywhere in our lives - art, gym equipment, math, designs, furniture, jewelry, mining companies,” Gregory Barord, one of the study’s authors, told McClatchy News over email. “Yet, very few folks know anything about the living animal that is inside the shell and fewer have ever seen a live nautilus.”

Researchers observed the previously undocumented cephalopods off the coasts of Fiji, American Samoa and Vanuatu, according to the study.

Baited traps were dropped several hundred meters into the ocean in order to catch the creatures, which were then hauled onto boats.

After the specimens were photographed and sampled, they were dropped back into the water and escorted home by attentive divers who “burped” them, researchers said.

“When we take nautiluses out of the water, they are still using their hyponome (funnel) to ventilate,” Barord said. “When this happens, air can get trapped in the shell and if it is not burped out, the nautilus becomes positively buoyant and cannot jet down back to its home, 300 meters below.”

Following the expedition, shell characteristics, such as size, pigmentation and stripe patterns were analyzed and used to identify three unique species, researchers said, adding that there are likely many more waiting to be discovered.

Their species diversity stems from the isolation of nautilus populations, researchers said. Because their shells will implode in the deep sea, and the surface water is too warm, they cluster themselves in habitable pockets of the ocean.

Researchers said the three species were found on the eastern end of the Nautiluses’ habitat.

Their discovery “provides insight into evolutionary radiation of the genus and clarification for future conservation practices,” according to the study.

“The fact that we were able to combine the morphology and genetics to differentiate these species provides a foundation for managers and other officials to begin to efficiently identify distinct species of nautilus shells that may come through as trade products,” the study said.

Despite the discovery of three new species, many questions about nautiluses, including those related to their diet, mating habits and predators, remain unanswered and require further examination, Barord said.

“Ironically, the thing we know best about nautiluses is how quickly their populations decline as a result of unregulated fisheries,” he said. “Our conservation group, Save the Nautilus, thus, is trying to learn as many things as possible about their biology, behavior, and conservation as we can to prevent future decline and potential extinction, even as fisheries most likely continue.”

Nautilus populations have declined by as much as 80% over the past few decades as a result of commercial interest in their shells and meat, according to Oceana, a non-profit focused on conservation.

This story was originally published February 22, 2023 at 4:19 PM with the headline "Newly discovered sea creatures had to be ‘burped’ to get back home, researcher says."