More than thirty years ago, a Panamanian biologist named Arcadio Rodaniche observed unusual behavior in a rare octopus and tried to publish his observations. Finding his anecdotes and intricate ink illustrations of the creature too unbelievable, the scientific journal rejected his work.

So goes the prelude to biologist Roy Caldwell’s current study of twenty-four Larger Pacific Striped Octopuses in his laboratory, which picks up where Rodaniche left off. And among the strangest behaviors Caldwell’s research team at the University of California, Berkeley, saw were related to mating.

What’s so exciting about octopus sex? In the case of Caldwell’s octopuses, they are freaks in the sheets. They mate aggressively—tangled in tentacles—with the female almost appearing to eat the male. On top of that, they also discharge streams of ink.

Most other species of octopuses are nowhere near as daring as Caldwell’s. Female octopuses are known to be dangerous cannibals that devour with their beak-like mouths. This is not so fun for the males, who cautiously hand over their sperm, resisting the femme fatale at tentacle’s length. For them, sex is dreary, yet still a life or death ordeal.

Caldwell’s octopuses, in comparison, fight dirty yet get along at the end of the day. They share a den and eat food together. They aren’t biting off each other’s heads, but “sucker marks” (think octohickies) hint at other devilish antics. Social behavior like this is almost unheard of with octopuses.

Accompanied by photographic and video recordings, Caldwell’s research was published in PLOS ONE last August. “These are animals that live in a habitat that often gets ignored,” says Huffard, a marine biologist who worked with Caldwell. “This is just one that has lots of potential for study and conservation efforts.” Huffard got involved with Caldwell’s current study “right as the stories got stranger and stranger.”

Perhaps the ocean is like the Internet—the deeper we go, the weirder the stuff we find.