This Rare Octopus's Mating and Preying Habits Have Cephalopod Fans Psyched

A super-cool but little-known octopus has totally psyched the cephalopod community. Researchers recently resurrected scientific inquiry on the larger Pacific striped octopus (LPSO), which has so far turned out to be a complete black sheep in the octopus world.

In a study published in the journal Plos One, cephalopod experts focus on the larger Pacific striped octopus' quirky behaviour as well as its unique colorings. Their study also confirms the findings of cephalopod expert and painter Arcadio Rodaniche, who started studying the species in Panama in the 1970s.

"Arcadio came across this unusual octopus in Panama in the 1970s. He kept them in large aquaria and made a number of interesting observations," Roy Caldwell, co-author of the paper and a biology professor at the University of California, Berkeley, told me.

Rodaniche, an early advocate of the species, observed and spoke of the octopus's unusual appearance and quirky behaviors both in the wild and in captivity during the 1970s, said Caldwell. However, back then, his observations were deemed way too out there for the wider cephalopod community, and the larger Pacific striped octopus was largely ostracized from research circles.

In 2012, Caldwell and Christine Huffard, a researcher at Monterey Bay Aquarium Research Institute, resurrected research on the enigmatic octopus, and actually confirmed Rodaniche's initial findings, which stated the octopus' unique coloring and behavior. This subsequently fired up the curiosity of cephalopod biologists worldwide, and now everyone wants a piece of the research pie.

So what makes this octopus so unique? For starters, the larger Pacific striped octopus (there's also a lesser Pacific striped octopus) has unconventional mating and reproductive habits and eccentric predatory behaviors, and is pretty friendly as far as cephalopods are concerned. It's also a real fashionista, sporting high-contrast patterns and colours that encompass everything from pales to dark reddish-brown colors to black with white stripes and spots.

"The most hypnotic aspect of their behavior is predation," Caldwell told me. While all octopi pounce on their prey and poke their arms into crevices and cavities to spook potential prey, the LPSO is different. "When it sees prey, it'll crawl out and stalk their prey," said Caldwell. He described how the LPSO reached out a tentacled forearm over its prey, scrunched up the tip and used it to tap its so it jumped back towards the waiting octopus.

A video showing a larger Pacific striped octopus preying on a shrimp.

Perhaps the most exciting discovery around this octopus is its peculiar mating strategy.

Instead of transferring sperm packets to the females at a distance like other species, males and females of the larger Pacific striped octopus actually cling to one another in a close beak-to-beak, sucker-to-sucker embrace while mating. These octopi like staying in the same position to share a meal, and are happy to cohabit the same den. The females octopi can also lay many clutches of eggs and continue to feed, mate, and lay even more eggs, after her current batch of eggs start hatching. This contrasts to other octopus species where the female meets a sudden and untimely death after producing just one clutch of eggs.

Next up, the researchers want to observe the larger Pacific striped octopus' behavior in the wild. They think that they'll glean some sharper insights into this octopus's quirky character as it interacts in larger groups. Back in the 70s, Rodaniche actually caught up to 40 individuals living together in tropical Eastern Pacific waters, kibbutz-style.

Caldwell told me, however, that there had only been five recorded sightings of groups of larger Pacific striped octopus in the wild. Caldwell said that to date, there wareere roughly 300 known species of octopus, but that existing knowledge of octopus was mainly based on a dozen or so species. The main reason for this, he said, is that octopi usually inhabit deeper waters, and it is incredibly hard for researchers to investigate them in the wild.

"There may be more octopi with similar behavior to the larger Pacific striped octopus, but we just don't know yet," said Caldwell.

After so many decades of scientific neglect, the cephalopod community are finally affirming Rodaniche's observations, and aiming to unravel the scientific mystery around what makes this alternative octopus species so unique and different from the rest.