Tuesday, November 26, 2013
Saturday, November 23, 2013
Stop me if you’ve heard this one before. A fish walks into a bar and takes a seat. The bartender asks what he wants to drink, but the fish doesn’t say anything. So the bartender asks, “What, cat got your tongue?” The fish grabs a cocktail napkin and writes out, No, actually, it was an isopod. An isopod got my tongue and by “got” I mean she ate it.
That joke may not be funny to you, but it’s hilarious to the tongue-eating isopod. You see, in the Gulf of California there actually exists a critter, Cymothoa exigua, that targets a fish by infiltrating its gills and latching onto its tongue. It proceeds to not only consume the organ, but will then replace it with its own body, providing the fish with a new fully functioning tongue it uses (probably a bit begrudgingly) to grind food against tiny teeth on the roof of its mouth.
If you can believe it, this is a love story at heart. And the rose snapper’s face is the stage on which it unfolds.This remarkable attack is the only known instancein the animal kingdom of a parasite functionally replacing an organ of its host. And while C. exigua targets several other fish, attaching to their tongues and draining their blood, only with the rose snapper does it devour and completely replace the organ as an operating structure, according to marine biologist Rick Brusca of the University of Arizona. And he stresses that while there are hundreds of such species of tongue-targeting isopods, contrary to many media reports, only C. exigua can actually truly assume the duties of the organ.
These isopods are protandrous hermaphrodites: They first mature into males, but then switch sexes to become females. The magic starts when more than one C. exigua lands in a given fish’s gills. When the first one infiltrates it begins to mature into a male, but when the second one appears, said Brusca, it “stimulates the first one to change sex and become a female and crawl from the gills up through the throat and attach to the tongue, and then this new second one is the male that will impregnate her.”