Apr 9, 2009

Blood-filled Barnacles

Morgan saw that I had been on a spree of posting on marine parasites and predators, and so thought to add some more ugly to the salty stew.

You're looking at what is described as "red, sausage-sized structure [which] is the external portion of an unusual, parasitic barnacle, Briarosaccus callosus." Charming. These barnacles, which turn red as they become engorged with crab their own hemoglobin (thanks for the correction, anon3), render their hosts sterile, use the crab's energy to produce swarms of baby parasitic barnacles, and can even induce the crab to protect the barnacle and assist with larval release.

Photo source: Tom Shirley via NOAA





















The only danger I've ever thought of in association with barnacles is the occasional knee or palm scrape I get when I clamber about tidal pools. But then, my experience has been limited to benign barnacles (a possible band name), and I'm not a crab. I can't imagine what it would be like to have a blood-filled barnacle sticking out of my belly button and telling me what to do. Suddenly ticks and lice don't seem so bad.

Thanks, Morgan. And good luck with your BA thesis.
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10 comments:

  1. Anon3April 09, 2009

    "These barnacles, which turn red as they become engorged with crab hemoglobin"

    That doesn't sound right (I know you took it from the NOAA site). From my own experience drawing crab hemolymph (the "blood"), most crabs have clear hemolymph with a greenish or bluish tint to it. I guess that particular group of crab scould be different, but I highly doubt it.

    http://www.cityweekly.net/utah/article-6138-the-straight-dope-there-will-be-blood.html

    "After hemoglobin, hemocyanin is the second most commonly encountered blood pigment, and plenty of other arthropods (including lobsters, crabs of the nonhorseshoe variety, and assorted insects) and mollusks (among them snails and octopuses) have blue, copper-based blood."

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  2. Anon3April 09, 2009

    Aha, it's not CRAB hemoglobin, it's barnacle hemoglobin.

    http://www.bioone.org/doi/abs/10.1668/0003-1569%282001%29041%5B1057%3AOOCRP%5D2.0.CO%3B2

    "Hemoglobin is present in Branchiopoda, Ostracoda, Copepoda, rhizocephalan Cirripedia and one suborder of amphipodan Malacostraca, while hemocyanin has been described in Malacostraca."

    (translation: barnacles (cirripedia) have hemoglobin, while crabs have hemocyanin (Malacostraca)).

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  3. Raging WombatApril 09, 2009

    Thanks for the correction, anon3. I've fixed it. Are you the same anon3 of mystery catfish fame?

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  4. RasmusApril 09, 2009

    Speaking of parasites...

    http://people.smu.edu/eheise/Leucochloridium_paradoxum.htm

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  5. Anon3April 09, 2009

    "Are you the same anon3 of mystery catfish fame?"

    Yep

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  6. Raging WombatApril 09, 2009

    Right on. Again, thanks for the correction.

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  7. AnonymousApril 09, 2009

    I don't think that's a barnacle. I think it looks more like an electric eel. In fact, I'm sure it's an electric eel and can say with 100% certainty: electric eel.

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  8. Raging WombatApril 09, 2009

    Oh no! The debate rages on!

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  9. ktbug ladydidApril 10, 2009

    exactly what part of the photo is the barnacle?

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  10. UnknownApril 13, 2009

    Um, I believe it's the cleaned carapace of a cooked spiny lobster. Someone is having a good laugh right now.

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