New Frilled Giant Pacific Octopus Discovered in Alaska

Enteroctopus dofleini, or the North Pacific giant octopus, pictured here, is thought to be related to the frilled giant Pacific octopus. Kirt L Onthank/Wikimedia Commons

Updated | Scientists have discovered a new species of giant Pacific octopus swimming right under their noses. Suspected for years, this is the first time researchers have confirmed the species both genetically and visually.

Distinctive fleshy "frills"

Called the frilled giant Pacific octopus, the mysterious creature has a bumpy ridge across its body, weird fleshy "eyelashes" and two white spots on its head.

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The newly discovered frilled giant Pacific octopus. The mysterious creature has a bumpy ridge across its body, weird fleshy “eyelashes” and two white spots on its head. D Scheel

Scientists published two papers on the species in the American Malacological Bulletin in November; one on its genetics and one on its body patterns. The research is part of Alaska Pacific University's Alaska Octopus Project.

The more common giant Pacific octopus—or Enteroctopus dofleini—is the largest known octopus in the world. The animals live around the coastal Northern Pacific and are found from Japan to California. The monstrous beasts can weigh more than 150 pounds.

Now a species related to the Enteroctopus dofleini has been discovered.

The existence of another species has been suspected since at least 2012, Earther reports. Alaska Pacific University and U.S. Geological Survey researchers found different DNA among giant Pacific octopuses in Alaska's Prince William Sound. After taking tissue samples, the scientists released the animals back into the wild.

This left the task of visual identification to Nathan Hollenbeck. He cataloged the distinguishing features of the species as part of his undergraduate senior thesis at Alaska Pacific University.

Shrimp-fishing bycatch

Instead of hunting down the animals himself, Hollenbeck left the catching up to local shrimp fishers. This allowed him to take a proper look at the creatures when accidently caught in hauls of shrimp. Every now and then, giant octopuses find their way into a baited shrimp pot—often with their bellies full of the shellfish.

"Usually the octopuses have eaten the shrimp," Hollenbeck told Earther, "so there's a lot of shrimp shells and legs and antennae."

David Scheel, Hollenbeck's adviser and co-author on the research and a professor of marine biology at the Alaska Pacific University, said, "Presumably, people have been catching these octopuses for years and no one ever noticed," Earther reports.

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A shrimp fisher holds one of his catch. Every now and then, giant octopuses find their way into a baited shrimp pot—often with their bellies full of the shellfish. Athit Perawongmetha/Reuters

Less invasive genetic testing

As well as documenting the way the newly discovered species looks, Hollenbeck and his team tested a swabbing method of DNA sampling. Rather than snipping chunks of tissue from the animals like the 2012 researchers, his team used simple foam-tipped swabs and some salty preservation buffer.

They were able to match the different DNA samples to the weird-looking frilled octopuses. Related but distinct, they are a "genetic sister" to the standard giant Pacific octopus.

Different bodies, different lifestyles

What seem like quite small differences between the species might be indicative of more distinct lifestyles. The frill, for example, might be a sign of these differences.

Scheel told Earther, "I've been thinking: Why would an octopus have a ledge coming off its body like that? Maybe we're seeing differences in their habitat selection and ecology reflected by differences in their body."

Further work must be done to properly catalog the new species which, as yet, has no official Latin name.

This article has been updated to include a photograph of the newly-discovered frilled giant Pacific octopus.