Living the Scientific Life (Scientist, Interrupted)

Hagfish and Their Slime

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I learned about hagfish in my vertebrate zoology courses. Basically, hagfish are mysterious jawless fishes that live in the ocean. Despite being classified as vertebrates by many zoologists, they lack vertebrae, thus they are considered to be very primitive fishes. When threatened, hagfish secrete a mucus that forms threadlike fibers similar to spider’s silk. When mixed with water, a small amount of this mucus can tranform itself into an astonishingly huge slimeball, as seen in the video below the fold. It has been observed that hagfishes use this slime as a self-defense mechanism. After danger has disappeared, they rid their bodies of this slime by tying themselves into a knot. The knot travels from their head to their tail, ridding their body of the slimeball.


  1. #1 biosparite
    April 27, 2007

    Gives me a whole new appreciation for Bush, Cheney and Gonzales.

  2. #2 ACW
    April 27, 2007

    I don’t think most modern taxonomists include hagfish in the vertebrates, although they are clearly more closely related to vertebrates than the other chordate outgroups (the tunicates and the lancelets).

    In order to solve the nomenclature problem, chordate taxonomists instroduced a new taxon, the craniates, which contains two daughter taxa, namely vertebrates and hagfish. Chordates as a whole are now considered to be divided into three groups: tunicates, lancelets, and craniates.

  3. #3 matt
    April 27, 2007

    And, horrifyingly, the slime can be used in baking as an egg substitute!

  4. #4 Diane in Ohio
    April 27, 2007

    Eeeeeeww – Is the composition of this “SLIME” safe to eat? YUCK – now I’m skipping supper! Although Matts’ link did have some good prospects for potential use…

  5. #5 Chris' Wills
    April 28, 2007

    Aren’t eel skin wallets actualy made out of hagfish in the USA?
    I vaguely remember that from an episode of mythbusters.

    As for cooking with the slime,; who is going to collect it?

  6. #6 daedalus2u
    April 28, 2007

    This is very interesting. I am working with autotrophic ammonia oxidizing bacteria, and have found that they are commensal surface bacteria for many eukaryotes. They oxidize ammonia leaking through the skin into NO and nitrite. So far, I have found good biofilms on lobsters, clams, mussels, turtles, and earthworms. Frogs and perch didn’t have one. I suspect that the NO the biofilm produces may be a good feeding signal for preditors. The only source of NO in the environment is going to be the surface of living organisms which would be good to eat.

    If hagfish do have such a biofilm, a lot of it likely stays with the slime and produces a NO decoy signal, sort of like the flares that aircraft release to decoy heat seeking missiles.

    I suspect the hagfish slime would be similar to the mucus that is the basis of bird’s nest soup.'s_nest_soup

    If hagfish slime did evolve as a preditor decoy, it probably does taste pretty good. It might even have compounds that provide the illusion of satiation, so the preditor doesn’t go looking for something more substantial.

  7. #7 Monado
    June 8, 2007

    I stumbled across this Straight Dope article about eelskin wallets demagnetizing bank cards. At the very bottom it mentions that “eelskin” is usually “hagfish skin.”

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