"So, naturalists observe, a flea has smaller fleas that on him prey; and these have smaller still to bite ’em; and so proceed ad infinitum."
- Jonathan Swift

August 18, 2010

August 18 - Profilicollis altmani

Parasites that have complex life cycles involving marine creatures really baffle me - the odds of them completing their life cycle just seems so unlikely - and yet they do. Profilicollis altmani is a species of acanthocephalan (thorny-headed worm) that uses mole crabs (Emerita spp.) as its intermediate hosts and then infects shore birds like Herring Gulls as the definitive host. The adult parasite attaches to the intestines of the bird and then will release eggs into its feces where they somehow make their way to new foraging crabs. This parasite is also of recent interest because it appears to have jumped hosts into sea otters, where it can cause fatality. The otters are not normally hosts of these parasites, but perhaps are becoming infected as a result of eating prey that they normally do not.

Photo by Tricia Goulding, Romberg Tiburon Center for Environmental Studies, San Francisco State University.

7 comments:

  1. Cool parasite with an interesting life cycle. Check out http://limpetsmonitoring.org to find out about a sand crab monitoring program that surveys the prevalence of these parasites inside the crabs.

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  2. I happened to stumble upon this blog the same day you posted P. altmani, which happens to be the acanthocephalan I am studying for my master's degree! I think that acanthocephalans are really an interesting group that deserve to be researched more. I actually took that picture above from one of my crab dissections! :)

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  3. Wow - very cool. May I credit you, Tricia?

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  4. Sure, that would be great! Thanks!! I'm doing my research at the Romberg Tiburon Center for Environmental Studies, SFSU.

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  5. Our group in Invertebrate Zoology have seen this on the gills of our Scylla serrata during disection. Can we say that any crab can become an intermediate host for Profilicollis altmani?

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  6. I did some more research about other crab gill parasites and I've compared our samples to the other parasites and realized that our sample was not Profilicollis altamani but Octolasmis mulleri XD

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