It’s been too long since I’ve been able to return to the longstanding B-plot of my blog: The science of our cephalopodic peers. Really outstanding squid science doesn’t come along very often, in part because the enigmatic beasts — particularly the deep-living ones — are so hard to study. They roam mostly in solitude, generally eschewing contact with one another: The flesh UFOs of the briny deep. But every one in a while we get some really good video evidence of their activity. And what do we find?

Frenetic orgies of gay squid sex.

That’s the conclusion of “A shot in the dark: same-sex sexual behavior in a deep-sea squid”, the title of which ought to win some sort of literary award. The researchers got their hands on footage of 108 Octopoteuthis deletron, a squid that lives at mesopelagic depths (i.e. 200 meters to 1,000 meters). What the scientists were looking for was evidence of how, precisely, these squid mate with each other.

Here’s the thing: Given how deep O. deletron live, they don’t have much light to work with. Scientists have always suspected that the male squid have no idea whether the partners they randomly encounter during their plutonian wanderings are, y’know, female. So what does O. deletron do? Sniff out some subtle odor? Detect some faint bioluminescent marker of the sex of its potential partner?

Nope. It’s much simpler.

They just try to have sex with anything they come in contact with.

When the scientists took screengrabs of the squid, they found that the male and female squid were equally like to display evidence of having had sex with another dude. During sex, the male ejaculates packets of sperm towards its partner, which implant themselves in the partner’s skin. (The packets are called “spermatangia”, and there’s an animation of how it works here that is very cool but which you may not want to watch just before you eat or something.) Anyway, the fact that the male squid and female squid were equally shot up with sperm indicates that “male squid routinely and indiscriminately mate with both males and females.”

Why aren’t they more careful? Because the cons of trying to mate with anything that moves (it’s inefficient; you lose a lot of sperm that way) are outweighed by the fact that if you try to carefully verify the sex of the rare squid you encounter, you might never have sex. It’s a volume business. Or as the researchers put it:

The combination of a solitary life, poor sex differentiation, the difficulty of locating a conspecific and the rapidity of the sexual encounter probably results in the observed high frequency of spermatangia-bearing males in this species. Apparently, the costs involved in losing sperm to another male are smaller than the costs of developing sex discrimination and courtship, or of not mating at all. This behaviour further exemplifies the ‘live fast and die young’ life strategy of many cephalopods.

Finer scientific prose cannot be had.

This sort of indiscriminate gay male sex has not been observed in other flavors of squid, by the way. Apparently male Octopoteuthis sicula have been found with spermatangia implanted in their skin, but in that case it appears to have been a sort of autoerotic mistake. If you’re a squid having sex it’s super dark, you can’t see anything, and there are a lot of limbs flailing around … so apparently it’s pretty easy to shoot yourself with your own sperm. (Or as the authors put it: “Accidental self implantation during mating with a female is also a possibility.”)

By the way, that paper is available for free in full text; it’s only four pages long and is really a blast to read, so go check it out!

(That picture is from the Monterey Bay Aquarium Research Institute!)