Body-snatching Barnacles and Zombie Crabs

I stole the title to this post because I loved it so much (and I couldn't think of something better). Turns out not all barnacles are conical-shelled crustaceans that began life as free-floating plankton. Some barnacles are the scourge of any crab they encounter.

When the female Sacculina barnacles invades a crab's body, she does so in an amorphous gelatinous form. She then sends roots throughout the crab's body and begins to feed on it while she grows into a tumorous growth. She even carves out a little spot (the barnacle equivalent of a studio apartment) for the male Sacculina so that she might have baby Sacculinas. But the barnacle doesn't stop there.

Photo source: hku.hk
She seizes control of the crab's mind and forces it to do her bidding. The crab ceases to grow and looses the urge to mate. Instead, it unwillingly devotes itself to caring for the barnacle's eggs, using all of its time and resources to do so (disciplining the barnacles youngsters when they get rowdy, reading to them, singing lullabies just before nap time, etc.). The barnacle even alters the physiology of a male crab so that it becomes a female, so that it might better tend to the eggs.

Come on. I know all creatures need to make a living, but some just take it too far. Some parasites manage to be beneficial, and some become tongues. This one just owns its host in every conceivable way and then discards it. My neighbor has a mooching, parasitical son, who I now suspect might be a variant of the Sacculina barnacle.

Thanks for the link, anonymous.