Slowly sneaking up on its prey and carefully reaching an arm over to tap it on the shoulder, the larger Pacific striped octopus startles its food into its arms. As if this recently observed behavior weren’t weird enough, the bizarre cephalopod breaks many of the accepted norms associated with octopus behaviors. Normally, octopuses are solitary, mate very tentatively due to the female’s habit of eating the male, and only lay a single clutch of eggs before dying. Yet members of this particular species have been found living in groups of up to 40, mate mouth-to-mouth, and produce multiple clutches over a period of months.   

“I've never seen anything like it,” explained Roy Caldwell, who coauthored a paper on their ecology and behavior published in PLOS ONE. “Octopuses typically pounce on their prey or poke around in holes until they find something. When this octopus sees a shrimp at a distance, it compresses itself and creeps up, extends an arm up and over the shrimp, touches it on the far side and either catches it or scares it into its other arms.”

The octopus was first observed by Aradio Rodaniche, a biologist from Panama, in the 1970s when diving in Nicaragua. He eventually wrote up his discovery and in 1991 submitted his paper describing the new species to the Bulletin of Marine Science… which rejected it on claims that the behaviors he described were too bizarre and weird. The cephalopod passed into obscurity, until Caldwell rediscovered it a few years ago and decided to keep some in captivity. Yet still to this day, the larger Pacific striped octopus lacks a formal scientific name.  

^{A larger Pacific striped octopus showing off its beautiful coloration while displaying to its mate. cephhead/YouTube.}

Alongside an amazing hunting strategy, they also display rather strange mating behaviors. Rather than doing the deed briefly once at arm’s length, the pair cohabit together, sometimes even sharing meals. Over a period of months, they will mate multiple times, grasping each other sucker-to-sucker and beak-to-beak, as if kissing.

Despite being called the larger Pacific striped octopus, the cephalopod is actually quite diminutive in size, with females reaching only 7 centimeters across (3 inches) and males coming in even smaller at less than 4.5 centimeters (2 inches). They often show black and white patterning of stripes or spots, but can change to other colors, which they often do while displaying or mating. They normally live in murky water 45 meters deep (150 ft), near estuaries, adding to the difficulty of studying them in the wild.   

“Personally observing and recording the incredibly unique cohabitation, hunting and mating behaviors of this fascinating octopus was beyond exciting – almost like watching cryptozoology turn into real-life zoology,” said Richard Ross, who has been studying the octopuses with Caldwell. “It reminds us how much we still have to learn about the mysterious world of cephalopods.”