Nice and Weird: Dispatches from The Depths of Parasitology

It feels like a homecoming: I'm among hundreds of people who live for parasites.

I arrived in Arlington Texas this afternoon to attend the annual meeting of the American Society of Parasitologists. I'm going to give a talk tomorrow about the public awareness of parasitology, talking about my long-term relationship with the beasties in books, articles, blogs, and beyond. But till then, I get to hang out with parasitologists. I've met a lot of the people here over the years, like the leech-master Mark Siddall, and I've read the work of a lot of people I'm just meeting (work on things like how lice jumped from gorillas to human ancestors).

And I'm also hearing new people talking about research I've never heard before--"nice and weird," as one parasitologist described the species she studies. I heard about a parasite in Nebraska, a flatworm called a trematode (Halipegus eccentricus), that scientists discovered living in the ears of bullfrogs. But the trematodes in their ears are all adults. Matt Bolek from the University of Nebraska described how he and his colleagues had figured out the rest of the parasite's life cycle. The parasites release their eggs from the frog ears, which then get scarfed up by snails, where they hatch and start to develop. Then they leave the snails and swim in search of little aquatic invertebrates called ostracods. The ostracods get eaten by the larvae of damselflies, which then mature and fly into the air, only to be devoured by frogs. The parasites escape the damselflies and move through the bodies of the frogs to their ears. One trematode, four hosts.

And you thought your commute was long.

Tomorrow I'll blog about more of these marvelous beasts.

[Image courtesy of Matthew Gilligan]

[Update: In answer to commenters--that's an invertebrate known as a isopod that's eaten the fish's tongue and is now sitting where the tongue used to be. Nice and weird, baby.]

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Whoa, what is that thing on the fish?

How do the eggs get out of the ears of the bullfrog? Are the eardrums punctured?

By Dale Hoyt (not verified) on 28 Jun 2008 #permalink

I happen to be in Arlington contemplating a career in science writing... should you casually mention a restaurant in the area, you may find a fan listening at your feet. ; )

-Peace, Pteryxx