By Jonny Lupsha, Wondrium Staff Writer
A sea creature that washed ashore near Seattle may be a seven-armed octopus, Live Science reported. The bright red swimmer surfaced at Ebey’s Landing on Whidbey Island, Washington, August 29. Cephalopods are jet-propelled.
According to Live Science, a recently beached cephalopod sparked curiosity and debate among marine biologists. “A mysterious, many-armed sea creature—initially described as a large ‘red glob’—lying on a rocky shore in Washington has drawn in cephalopod experts across the country, each wondering what this gelatinous animal is,” the article said.
The most likely answers, which included the East Pacific red octopus and vampire squid, proved false, leading scientists to consider that it may be a seven-armed octopus (Haliphron atlanticus).
“The seven-armed octopus is an animal of ‘least concern,’ meaning it’s not considered to be threatened, according to the International Union for Conservation of Nature. However, its population size is unknown; and scientists know little about its habitat.”
Active swimmers in the ocean make use of their unique physiologies to navigate the sea. Invertebrates like the seven-armed octopus are no exception.
Passing the Swim Test
Several criteria make a species of a marine life a better or poorer swimmer—fins not necessary.
“Those basic characteristics are, first of all, streamlined in shape, and second, energy efficient and effective propulsion,” said Dr. Harold J. Tobin, Professor in the Department of Earth and Space Sciences and Director of the Pacific Northwest Seismic Network at the University of Washington in Seattle. “We’re all familiar with the idea that there is a certain shape that’s aerodynamic, if you think of cars and airplane design and things like that, or wind design—you know that a kind of teardrop shape is the one that is called aerodynamic and that’s for a very good reason.
“It’s the shape that, in a wind tunnel, produces the least drag and the least turbulence.”
Dr. Tobin said that the rounded front of a teardrop shape helps separate air lines around the shape; so air has an easier time moving above, around, or below the shape. However, water is far thicker than air, so minimizing drag is even more important underwater. If we consider the shape of the head of a creature like a squid or octopus, it’s easy to imagine the water flowing all around it as it propels itself through the ocean.
Why Not Call It a Septopus?
The seven-armed octopus Haliphron atlanticus is an invertebrate—more specifically, a cephalopod. Dr. Tobin said that squids, octopi, and mollusks make up most cephalopods, and they get their name because they all have tentacles, like feet, that come out directly from the head. He also said that they have a decentralized nervous system, with parts of what we could consider a brain distributed throughout the tentacles as well as the head.
“They have a body or mantle that they primarily move around by jetting water out of jets, so they’re basically jet-propelled,” he said. “They feed very effectively by using those tentacles to capture prey and move it into their mouth and move it into their gut. They have lots of other interesting adaptations like the ink that are produced by squids and octopus to confuse prey and predators.”
Although they don’t swim in the sense that fish do, with fins, these jet-propelled creatures swim nonetheless. Due to their torpedo-like shapes, Dr. Tobin said they’re remarkably efficient swimmers. Squid often swim in schools and were long thought to be slow-moving creatures, but nothing could be further from the truth.
“Mid-water squid in particular are very rapid swimmers, very active predators, and very successful organisms over a very long period of time in the history of the ocean.”
Edited by Angela Shoemaker, Wondrium Daily
Dr. Harold J. Tobin contributed to this article. Dr. Tobin is Professor in the Department of Earth and Space Sciences and Director of the Pacific Northwest Seismic Network at the University of Washington in Seattle. He earned his BS in Geology and Geophysics from Yale University and his PhD in Earth Sciences from the University of California, Santa Cruz.