Yup, those are barnacle balls. ON A CRAB.
Barnacles are usually pretty harmless. They attach themselves to a rock, stay inside their shell, and spend their lives filter feeding while trying not to say or do anything offensive. Sure, they might be kind of sharp, and you might’ve cut your foot on one before, but that was your fault. The barnacle was just sitting there quietly, swaying its weird little body in the current, whistling whatever tune it is that barnacles whistle, until you came along and stomped on it. But there is one barnacle that’s not so innocent. In fact, I’m pretty sure that it might be one of the most repulsive, invasive, and opportunistic creatures in the world – and I’m including your ex-wife/husband. It’s called the rhizocephalan barnacle.
Rhizocephalan barnacles don’t really have bodies, at least not in the traditional sense. They’re more like a root system in a tree – if the root’s eventual goal was to blow a hole in the tree and hang its reproductive organs out for the world to see like some kind of lewd flasher. And of course, if you’ve ever seen a tree, you know this is not what root systems do. Maybe that tree in Poltergeist, but that thing was also a kidnapper.
So here’s the deal: let’s say you’re a crab. You’re cruising around, pinching things and waving your eye-stalks around, cracking lobster jokes with the other crabs, when you feel a slight prick on your gills. Your shell is thinnest there, so it might worry you a bit, or it would if you had the brain capacity to worry. You know what that prick was? The larva of the rhizocephalan barnacle quietly injecting its guts into you. This little tube of barnacle guts is called a vermigon, and if you’re a crab, it is most definitely not something you want inside you.
Now that the vermigon has taken up residence, it starts to grow, feeding on the crab’s fluid-filled cavities. At this stage, it’s called the interna. It starts branching out like a root throughout the entire body of the crab, focusing on the digestive tract where there are plenty of nutrients to keep a life-sucking parasitic barnacle bent on eventual mind-control alive. For some reason, the host crab’s immune system doesn’t seem to get the message that there’s another creature growing inside it, and never tries to kick it out. Well played, barnacle.
Once it’s all grown up, the interna – remember, that’s the name for the life-stage that the barnacle’s in – busts a hole through under the crab’s tail flap, then hangs a sac of gonads (disgusting) out, like some kind of ball-dangling exhibitionist. They’re attached to the host’s body by a stalk that emits pheremones to attract male larvae, who will eventually land on the gonads and inject their vermigon – that little tube of barnacle guts – into it. Ah, the magic of life.
Remember earlier when I called the rhizocephalan barnacle a “life-sucking parasitic barnacle bent on eventual mind-control”? Here’s where the mind-control part comes in. Crabs carry their own eggs under the tail flap. Some species of rhizocephalans are able to castrate the crab using chemicals, then trick the crab into taking care of their gonads as though they were the crab’s own eggs. It even works if the crab is a male, and would have never exhibited those behaviors in the first place.
So next time you’re eating a crab, be sure to check for a disgusting living root system that’s worked its way through the meat. Don’t eat it, unless you want to risk having a barnacles gonads bursting out of your abdomen like an Alien. Nah, that wouldn’t happen. Or would it?
An artist’s rendition of what it be like to be a crab full of barnacle. Bad.
