And now for some creepy parasitic procreation! When it comes to parasites, it's hard to choose from the array of weird, brilliant and often really troubling modes of self-replication. However, a lowly barnacle called rhizocephalans has a strategy so Machiavellian it deserves some attention here.
Rhizocephalans — we'll call it rhizo for short — doesn't look like your ordinary barnacle. As a young larva, rhizo floats around in hopes of encountering a passing crab. Given the size of the ocean, the chances are slim, but rhizos are produced in vast quantities, so a few are bound to find their targets.
Once a rhizo makes crab-fall, it latches on, develops a little syringelike appendage and injects its cells into the crab's system. The rhizo cells find their way to their host's sinus and there begin to grow a root system that spreads everywhere, eventually poking out in exactly the spot where a female crab would carry its eggs. The parasite then lays its own eggs there in a little sac.
For reasons not yet fully understood, if the crab happens to be a male it will actually change shape, widening its abdomen to more closely resemble a female. Also unknown is how exactly the rhizo convinces its host that the parasitic eggs it's carrying around are actually crab eggs. Then, as though in a scene from "Being John Malkovich," the parasite directs its host out to deeper waters where it can avoid predators and competition for food.
It's all a bit unsettling. But is it as disturbing as Hymenoepimecis argyraphaga? Read on to compare.