Biology

Jellyfish Nematocysts

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This might be one of those relatively “simple” systems that could–like the bacterial flagellum–become a primary example used by ID proponents.

http://www.eurekalert.org/pub_releases/2006-05/cp-nro050306.php

By using an electronic ultra-high-speed camera, researchers have characterized the explosive discharge of stinging jellyfish nematocytes and show that this event represents one of the fastest cellular processes in nature. The research is reported by Thomas Holstein of the University of Heidelberg and his colleagues in the May 9th issue of Current Biology.

Nematocysts (also known as cnidocysts) of jellyfish and other cnidarians are giant exocytotic organelles of the stinging cells used for prey capture and defense. These miniature cellular weapons contain a cocktail of hemolytic and neurotoxic poisons, making some cnidarians the most venomous animals known. Injection of the toxins requires an effective release mechanism that breaks the physical barrier of the prey’s outer-surface tissue. It was known already that a high pressure (15 MPa) drives nematocyst discharge, and that stylets can penetrate even thick crustacean shells. However, neither the kinetics nor the forces involved were known, simply because discharge is so fast that it had not been previously resolved by conventional high-speed imaging.

To clarify these issues, the researchers studied nematocyst discharge with an electronic framing-streak camera at a framing rate of 1,430,000 frames per second. They show discharge kinetics of nematocysts in Hydra to be as short as 700 nanoseconds, creating an acceleration of up to 5,410,000 g. The researchers calculate that although the accelerated mass is very small (~1 nanogram), a pressure generated at the site of impact is more than 7 GPa, which is in the range of that generated by some bullets, and sufficient to penetrate the cuticle of crustacean prey. The researchers propose that the high speed of discharge is caused by the release of energy stored in the stretched configuration of the collagen-polymer of the nematocyst capsule wall. This ingenious solution allows the cellular process of vesicle exocytosis to release kinetic energy in the nanosecond range by a powerful molecular spring mechanism.

7 Replies to “Jellyfish Nematocysts

  1. 1
    crandaddy says:

    Oh come on, Patrick! Surely you don’t think such a thing might actually have been designed do you? What are ya gonna tell us next? The Earth is flat, maybe? The sun is really Helios riding his chariot across the sky, perhaps? Everybody with any sense knows that designers of nature don’t exist design in nature is untestable nonsense! πŸ˜†

  2. 2
    jpark320 says:

    Dang that primordial soup can really “cook” something up huh?

  3. 3
    Mats says:

    When I read what you posted, Pat, I couldn’t help but reminding one thing that is trully amazing:

    “Biologists must constantly keep in mind that what they see was not designed, but rather evolved.” – Francis Crick (Nobel Prize Laureate in Physiology and Medicine), “What Mad Pursuit,” 1990, p.138 [Emphasys mine]

    I believe Dr Phil Johnson would ask “Why do they CONSTANTLY need to remind themselves of that?”

    It must be hard to be a Darwinisn biologist. Imagine you working in a field where you had to constantly deny what is screaming in your face. 😐 (Intelligent Design)

  4. 4
    Lurker says:

    It must be hard to be a Darwinisn biologist. Imagine you working in a field where you had to constantly deny what is screaming in your face.

    I guess the Darwinist aren’t familiar with the phrase “If it walks like a duck….”. Ya know, if it looks designed maybe it really is. Even Dawkins can see the design, but chooses to keep reminding himself that its not designed. That’s what delusional people do, right?

    “There is a better reason for studying zoology than its possible ‘usefulness’, and the general likeableness of animals. This reason is that we animals are the most complicated and perfectly-designed pieces of machinery in the known universe.”

    Dawkins, R., “The Selfish Gene”

  5. 5
    Mats says:

    *gasps* Did Richard Dawkins really say “designed” and “machinery” in the same breath?

  6. 6
    Joseph says:

    Funny, but it was my 8th grade research paper on sea jellies and nematocysts that started me down the road of wanting to be either a zoologist or a marine biologist.

    The smallest sea jelly also has the most powerful poison. If you get stung by a sea jelly pour vinegar on the spot. (do not urinate on it)

    (It was also very fortunate for me that electronics was my first love. I say that because I “had it out” with a couple of bio profs when evolutionism just did not fit the data we observed in the wild or in the lab.)

  7. 7

    Compare the https://en.wikipedia.org/wiki/Warnowiaceae which have nematocysts inside their single cell – oh, and an eye of some sort to boot.

    Ah, there seems to be a slight problem for Wikipedia in explaining how the two types of creatures both have the same weapon (https://en.wikipedia.org/wiki/Nematocyst_(dinoflagellate)):

    ‘It is unclear whether the relationship between dinoflagellate and cnidarian nematocysts is a case of convergent evolution or common descent, although molecular evidence has been interpreted as supporting an endosymbiotic origin for cnidarian nematocysts.’

    Andrew

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