Enteroctopus dofleini, also known as the Giant Pacific octopus is known as the biggest of all octopuses. However, recently scientists discovered that the Giant Pacific octopus is at least two species. Scientists accidentally discovered a new GPO species off the coast of Alaska, although it hasn’t yet been specifically named.
The new species, which is called the frilled giant Pacific octopus by the scientists who discovered it, was found when Nathan Hollenbeck and David Scheel from Alaska Pacific University took a look at shrimp by-catch which is a part of Hollenbeck’s senior-year thesis. Hollenbeck who is an undergraduate student at the university, and Scheel, a professor, discovered that not all octopuses that came in the bait-pots for shrimp were GPO.
Researchers, in order to catch shrimp, inserted shrimp pots with bait into the water, leaving the bait there for a day. Sometimes, octopuses get into the pots together with the shrimp, mostly because they eat the shrimp in the pots. Scientists caught a total of 21 cephalopods, where six were discovered to be of an unknown type.
“They were identified by an absence of longitudinal mantle folds, the presence of a lateral mantle frill comprised of a semi-continuous line of broad merged papillae forming a frill or flap along the mid-lateral mantle, the absence of papillae or rugose texture on the ventral mantle below the frill, and two distinctly separated frontal white spots (rather than a single simple or compound spot, or none),” the scientists said in a press release.
Basically, the GPO lacks the frill along the length of its body, which inspired the new species’ name that scientists are using until they come up with a scientific name. Another difference between the GPO and the other octopus is that the Giant Pacific octopus has one frontal white spot, while the new species has two.
In order to make sure that this is actually a new species, scientists ran a genetic comparison with dofleini and nucleotide sequence data, which revealed that they are two separate species.
“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,” Scheel told Earther in an interview.
The GPO can grow to over 150 pounds in weight, but adults mostly weigh around 33 pounds. The largest octopus of the new species that researchers found was a female specimen which weighed about five pounds, meaning that the newly discovered individuals could be juveniles.
More details about the distant cousin of the Giant Pacific octopus can be found in a paper that was published in the November edition of the journal American Malacological Bulletin, titled “Body Patterns of the Frilled Giant Pacific Octopus, a New Species of Octopus from Prince William Sound, AK.”
Another study included Sheel earlier this year. The study identified a rare octopus colony in the settlement off Australia’s east coast, revealing octopuses are not as solitary as originally thought.