Muses: Parasite of the Day

If you’ve read other blog posts here or followed us on Twitter, you’ve likely noticed that we kind of like parasites. A lot. And whether or not you can muster up the same fascination, it’s kind of hard to argue against their importance; roughly 40% of species on earth are parasitic, and as many as 75% of relationships in all foodwebs involve a parasitic interaction of some kind.

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Tirelessly working to inform the world of every last one of these amazing lifeforms is the brilliant blog Parasite of the Day. Writing up the unique behaviours of nematodes, hookworms, flukes and wasps with equal clarity and care, authors Tommy Leung and Susan Perkins have created what might actually be the best resource of its kind. I think what I like most about it is that it takes the appeal of its subject matter as implicit. There are no attempts to downplay the grossness or apologize for the squeamishness that might result from reading the posts.

Another extremely admirable thing about Parasite of the

This just in: Twitter users like cats (#MyParasite poll)

A couple of days ago we posted the first of a series we’re going to call “treasures”: stories about random things in science that we think are beautiful, surprising, amazing or just plain cool. They’re going to be paired with the little circular image icons on our homepage, which we’ll begin rotating, so over time visitors to our site will see a changing set of discoveries. Tuesday’s treasure was the tongue-eating sea louse, a parasitic crustacean that lives inside the mouths of fish—and does exactly what its name says.

Toxoplasma gondii. Photo © Ke Hu and John Murray, under a Creative Commons Attribution 2.5 Generic license.Once we tweeted the post, a flurry of folks started tweeting back naming their favourite parasites, so we decided to start a poll, using the hashtag #myparasite, for favourite parasite. We’ve storified the discussion here.

The results were, perhaps, predictable: people on the Internet like cats. Or, as one responder said, our parasitic overlords tell us to like cats. And by

Treasures: The tongue-eating sea louse

One of the things I love about science is the appreciation it can inspire for things I might otherwise consider horrifying, or just gross. One great example of this is Cymothoa exigua, also known as the tongue-eating sea louse. I should mention that the animal in question doesn’t necessarily “eat” the host’s tongue in the conventional sense: It latches on and consumes blood and mucus until the tongue completely shrivels up. Then the isopod crustacean stays right where it is and switches to just grabbing part of whatever the fish eats and slowly growing larger, before eventually detaching and swimming away. A few things about this before we go back to the whole wonder and fascination part…

Cymothoa exigua inside its host. Photo © Matthew R. Gilligan, Ph.D.First, if this doesn’t seem very healthy for the fish, that’s because it’s not. That much is pretty intuitive. What’s odd is that it’s not as unhealthy as you might imagine: while the overall fitness of host fish is negatively impacted, tongue-replacing isopods rarely cause death by themselves. Fish can apparently live just fine without a tongue,