Friday, October 8, 2010

Apple #486: Jellyfish

I went to a nearby aquarium with some friends this summer.  I meant to do a Daily Apple entry about some of the fish & animals & creatures I saw there, but I've only just now remembered.  So I give you: jellyfish.

I don't know what kind of jellyfish this is because the aquarium decided to get all entertainment-y, and they took all the "boring" stuff off their signs, such as the names for the animals.  But I do know this is some kind of jellyfish.  It was in a tank with curved glass on the outside and it was lit up with that bright pink light so the jellyfish would be visible.
(Photo by the Apple Lady)

Some Nice, Easy Facts
  • Jellyfish have existed for more than 650 million years.  That makes them older than dinosaurs, older than sharks.
  • Individually, each jellyfish lives for about three to six months.
  • Jellyfish never stop growing. However, since they don't live very long, "never" for most jellyfish is a short time.

This jellyfish was in a different tank than the pink one. I don't know what species it is, but it's a different one than in the first picture.
(Photo by the Apple Lady)

  • A group of jellyfish swimming together is called a smack.

This is a whole bunch of jellyfish.  A smack of them, I should say.  The colors didn't come out too well in the photo, but the frondy things -- which I guess must be tentacles -- are green on some of them, pale purple on others, and pale pink on still others.
(Photo by the Apple Lady)

  • Female jellyfish store their fertilized eggs in their "oral armpit," which is actually more mouth than armpit.
  • One fertilized egg turns into a polyp, which is sort of like a  seed pod.  The polyp generates more polyps off of itself.  The polyps  break open and inside of each one are several tiny jellyfish.

Jellyfish #3
(Photo by the Apple Lady)

    • Jellyfish are pretty simple, anatomically speaking. They do not have:
        • brain
        • central nervous system
        • circulatory system
        • respiratory system
        • bones
        • scales
        • shells
    •  Jellyfish do have:
        • epidermis (skin)
        • gastrodermis (skin around the digestive system)
        • mesoglea (fancy word for the jelly-like goo)
        • rudimentary digestive system
        • nematocysts (stinging cells)
    • Not all types of jellyfish have tentacles. The stinging cells might be on other surfaces of their bodies.

    Ah, don't these jellyfish look nice and peaceful, almost as if they're dancing?
    (Photo by the Apple Lady)

    The Rest of the Story

    You might be tempted to think that jellyfish are pretty and colorful and nice and simple.  But jellyfish are actually much more complex and capable than you might think.  In fact, it's possible that they could be taking over the world.  Or at least, the oceans.

    • Because of overfishing, jellyfish are able to reproduce pretty  much at will and with far fewer predators.  As a result many of our  oceans are approaching what scientists call a "jellyfish stable state,"  which will be when jellyfish effectively rule the ocean.
    • Echizen jellyfish, for example, are growing like mad off the coast of  Japan probably because of overfishing. This species can get to be over 7 feet in diameter and weigh more than  660 pounds. 

    This is the Echizen or Nomura's jellyfish, which live off the coast of Japan. Pretty dang huge.
    (Photo from Beer Steak)

    • Another species of jellyfish can avoid death.  Not by dodging predators or anything so basic as that.  They can make their cells literally get younger.
    • The fancy name for this process is transdifferentiation, and only the Turritopsis Nutricula jellyfish can do it.  In transdifferentiation, as a cell develops, it gets younger instead of older.  So basically this jellyfish, when it's had enough of aging, can make itself revert to a polyp state and essentially rebirth itself.
    • As far as scientists know, these jellyfish can do this over and over again, indefinitely.
    • Another type of jellyfish, the sea wasp or box jellyfish, kills more  people per year than any other creature in the ocean.  Including sharks.
    • That box jellyfish, by the way, has 24 eyes and 64 anuses. And 64 mouths as well; jellyfish use the same orifice for eating food and expelling  wastes.

    Here are a couple of pictures to show you what a box jellyfish looks like. Its cap -- for lack of a better word for it -- has a dome-like top and it comes down quite a ways over the tentacles. If you see one of these, get the heck away from it fast!
    (Photos from Destination-Scuba and Scubadoc, respectively)

    • What makes any jellyfish's sting so virulent is, to quote a scientist from a National Geographic video, "all the blood cells that are exposed to a jellyfish's venom will immediately swell up and explode." 

    If You Get Stung
    • If you've been stung by a box jellyfish, you've got 3 minutes to get the venom off you before you die.
    • Other types of jellyfish, it's not so dire, though it can be extremely painful.

    Jellyfish sting
    (Photo from

    Box jellyfish sting
    (Photo from Scuba-doc)

    • If you're having trouble breathing or swallowing, or if you're having chest pain, get thee to a doctor immediately.
    • Best thing to do is--no, not urinate on it--is first, get any stuck-on tentacles off of you.  Don't use your bare hands but use tweezers, a gloved hand, a stick--anything to peel off those  tentacles.
    • Then as soon as possible, rinse the area with any one of the following liquids.  In order of preference, most to least effective:
        • Vinegar
        • Rubbing alcohol
        • Either of the first two diluted with salt water
        • Salt water
    • Fresh water, ice, or hot water can make the nematocysts (stinging cells) release more toxins, so you definitely want to avoid using those.
    • If you've gotten stung around the eye, then use a ton of fresh water -- a gallon of it -- so as to overwhelm the nematocysts with a liquid that won't sting the crap out of your eye still further.
    • Even after you've plucked off the stingers you can see and after you've rinsed, you still probably haven't gotten all the stinging cells off of you, so apply shaving cream or baking soda or cornstarch or mud or sand to neutralize the stinging still further.  Then shave.  If you don't have a razor handy, use something like a credit card or a hotel key to scrape the area as best you can. 
    • Then rinse again with vinegar or alcohol.
    • Finally, wrap the area in an Ace bandage the same way you'd wrap a sprain, and take some aspirin.
    • After you've rinsed and bandaged yourself, you might want to go see a doctor anyway.  The doctor can give you Benadryl to calm any itching, steroids to reduce any inflammation, and pain medication if necessary.  It's also easy for jellyfish stings to get infected days later, so you may need antibiotics too.
    • A final word about the urine thing: some people say it helps reduce the sting. But it's a gamble. The thing in urine that works to neutralize the nematocysts is ammonia. But most people's urine has a far greater amount of fresh water than ammonia.  So urinating on a jellyfish sting can actually increase the pain, the same as pouring fresh water on it would.

    Some places in Australia where box jellyfish are particularly prevalent have gigantic hydrants like this one filled with vinegar.  This is because vinegar is the best thing to use to rinse off jellyfish stings.
    (Photo from Life in the Fastlane)

    Aquatic Community, Jellyfish Facts
    Roy D'Silva,, Facts About Jellyfish
    Beer Steak, Jellyfish Facts

    Scienceray, Weird But True: Jellyfish Facts
    Simon Crisp, Asylum for All Mankind, Giant Echizen Jellyfish Invade Japanese Waters
    Rod Brouhard,, How to Treat a Jellyfish Sting, Jellyfish Stings Treatment
    WebMD, Jellyfish Sting Treatment

    1 comment:

    1. This is interesting. I enjoyed reading this. I hope I never get stung by a box jellyfish!


    If you're a spammer, there's no point posting a comment. It will automatically get filtered out or deleted. Comments from real people, however, are always very welcome!