Glacial Errata, No. 72

One: Hapalochlaena lunulata

The cutie known as the Blue-ringed octopus is a beautiful, tiny little fella, not even four inches long, who lives in coral reefs in the Pacific and Indian oceans. Truly one of the prettiest species of octopuses, but those little blue rings are there basically to warn you to stay away, as they are one of the most toxic marine animals in the world. If threatened, they will first try to flee, but if cornered, they’ll flash their iridescent rings in a pattern at about one second intervals, and if you are somehow stupid enough to still try to pick a fight with these small, lovely little creatures, they will seriously fuck your shit up. Their venom instantly paralyzes the victim, so that they are unable to signal for help or indicate distress, though they remain conscious and alert, so they can be fully aware as their body stops working—death happens, ultimately, through the failure of the diaphragm to breathe. Somewhere between 11 and 16 humans have gone out this way. Seems bad.

Two: Tremoctopus violaceus

The rather unique-looking blanket octopus, on the other hand, relies on another strategy altogether: blanket octopuses are immune to the stings of the Portuguese man-o-war, and so females have been observed ripping off the stinging tentacles of passing man-o-wars, and using them as clubs, either for defensive or offensive purposes.

Three: Thaumoctopus mimicus

The mimic octopus is great because it can imitate several different kinds of other animals. It has been observed acting as a sole fish, lying flat on the ocean floor, or as a manta ray, shaping its tentacles behind it into the ray’s iconic tale. It can mimic a poisonous lionfish as well, matching its white and brown banding and spreading out its tentacles to match the lionfish’s spines. Scuba divers have also reported mimic octopuses transforming into seahorses, nudibranches, eels, jellyfish, and mantis shrimp as well.

And then there is perhaps my favorite trick of the mimic octopus. Damselfish, who can be aggressively territorial, will occasionally harass the mimic octopus. But the damselfish is preyed on by the banded seasnake, and somehow the mimic octopus knows this, so when it’s bothered by the damselfish, it will dive into a hole, and stick out two arms, with which it will use to mimic a black-banded sea snake. What a guy!

Four: Octopus cyanea

The Big Blue, or Day Octopus, was observed a few years ago punching fish, which, relatable. Just straight up socking groupers with a tentacle. Getting out some aggression, letting off some steam after a rough day maybe. But after observing the behavior more closely, we know now why. It turns out that the octopus collaborates with other species of fish (usually blue goatfish and groupers) in group hunts, where blue goatfish act as scouts, locating prey, and then the octopus moves in and flushes out the fish, so everyone can have a little snack. However, sometimes some of the fish (usually the groupers) don’t really pull their weight, and show up just at the end to mooch off the others’ hard work. The octopuses do not put up with this, and they will straight up punch these slackers to let them know what’s up.

Five: Enteroctopus dofleini

Finally, if you’ve never watched this video of this Giant Pacific Octopus dreaming, please do so. It’s two minutes of the most amazing footage you will ever see. And if you’ve already seen it, you no doubt already know what I mean, and you’ll happily watch it again, because it never ceases to be amazing.