Pyura Chilensis, the living rock

This is not a geode. It's an animal. An apparently delicious animals with clear blood, whose body is accumulates surprisingly large amounts of a rare metal used to strengthen steel.

This is Pyura chilensis—an immobile ocean creature. Besides the other traits I mentioned, P. chilensis is also capable of both sexual and asexual reproduction. At the Running Ponies blog, Becky Crew explains the results of a 2005 study that detailed the creature's breeding habits for the first time.

The results showed that P. chilensis is born male, before becoming cosexual – having both male and female gonads – in its adolescence as it increased in size. The researchers also found that given the choice – that is, if situated around other individuals – these organisms prefer to breed via cross-fertilisation, writing, “Given that more events of natural egg spawning followed by successful settlement and metamorphosis were recorded in our paired specimens and in our manipulated cross trials … it appears that cross-fertilisation predominates in this species.”

Manríquez and Castilla also found that a greater number of fertilised eggs resulted from the paired specimens, which suggests that cross-fertilisation, or reproducing with another individual, predominates because it is more effective. This assumption was strengthened by the fact that individuals that had cross-fertilised before being put in isolation took at least two months before successfully producing offspring via selfing. However, they were careful to note that while cross-fertilisation was preferred, selfing did not produce inferior offspring. “No perceptible differences in fertilisation, settlement and metamorphosis success among self and outcross progeny were found,” they reported. This suggests that when stuck alone in the ocean, selfing provides an advantageous opportunity for loner P. chilensis individuals to still pass on their genes.

Read the rest of Becky Crew's post to learn more about Pyura chilensis


  1. And looking at that picture the first thing that comes to my mind, naturally, is, “I’m a doctor, not a bricklayer.” 

    And after reading the article and learning that vanadium is the metal the animal accumulates, and that it’s eaten raw or in salads, what comes to mind is Spalding Gray and his macular pucker, caused, according to one of his doctors, by a buildup of vanadium in his system.

    1. We need to get Leonard Nimoy over there stat if we want to communicate with this thing.

      1. You’re third.
        (And Ryan Lenethen beat me to it, the darned tribble!)(That insult sounded better before I typed it.)

  2. I predict rapid identification of the mechanism for selective vanadium uptake, followed by patents, and commercial vanadium production from seawater soon to follow.  Oh wait, I just made prior art – now its all open source FTW. :)

  3. Buargh…. Piure is disgusting. I really don’t understand how my grandma loves to eat that stuff so much. I believe it has to have one of the strongest odors among seafood and the taste is like drinking yodine.

      1. People generally eat them mixed with onions, parsil and lots of lemon juice. Crazy people (and the divers that harvest the stuff) just open them and eat them directly.

    1.  Yeah, I remember eating some years ago. The shell had a consistence like a soft plastic covered in sand and the taste was so strong in iodine it required a lot of white wine to swallow.

    1.  Ah, you beat me to it. Isn’t that a cool fact? Yup, they’re chordates, which means they have spinal cords, but they’re invertebrates, so no spines.

      Speaking of weird sea creatures and what flies are more closely related to, barnacles are arthropods, meaning they’re much more closely related to flies than to clams, limpets, anemones, starfish, chitons… Counterintuitive, at least to me.

      1. yeah, that one always surprises  people (me included when I took  zoology many years a go). the telling thigns is the meat. if you eat barnacles you’ll see the meat is very much like crab meat. very tasty too. unlike piures which I hate.

  4. Living rocks… we’re one step closer to finally having real Pokémon.
    Geodude, I choose you!

  5. The Silicoids have the traits Lithovore, Repulsive, and Tolerant.  Unfortunately, we are unable to sign treaties with them.

  6. The story right above this one is about a woman getting her head cut off, then you scroll down and see that pic.  Oofah!

  7. I thought that it looked much more like the inside of a tomato than say… beef or meat.  Still, I think:  urk urk, DO NOT WANT.  (Plus, I don’t like tomatoes).

  8. Gees this takes me back to my school days. We had a science (biology) excursion and so our terrible adolescent bunch descended on a local (Sydney, Australia) tidal rock shelf and explored, doing untold damage. We were instructed to leave things where we found them but you know, 16 year old boys. The most fascinating were the turnicates (sea squirts) that had attached themselves onto the rocks in a carpet that was 10 – 20 centimetres thick. Aptly named “sea squirts” too. I didn’t realise they were edible but they are amazing critters. These days I live further north and although the water is warm and inviting the rock pool life is much poorer. Not many sea squirts. The lesson I took away from that day was that sometimes the most surprising things require you to look more carefully.

  9. Andrew Zimmern ate this on Bizarre Foods. And yes, he likened it to the Horta from Star Trek.

  10. “An apparently delicious animals with clear blood, whose body is accumulates surprisingly large amounts of a rare metal used to strengthen steel.”

    I think this sentence needs just a little fixing up.

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