22 October 2011

Wherein we learn about the "ampullae of Lorenzini" - updated with amazing video

Addendum to the original post (below).  A tip of the hat to expatQLD, who after reading the post below searched YouTube and sent me a link to the video showing this lady at work.  As it started I thought I was watching computer graphics because of the unbelievable abundance of sea life; then when I saw her rubbing the snout of the shark I realized this was Cristina Zenato at work.

By all means, click the fullscreen icon [bottom far right corner] to get full enjoyment of this video !!

From the DailyMail:
...She induces the 'tonic' state in the shark using a little-known technique of rubbing the ampullae of Lorenzini - the name given to hundreds of jelly-filled pores around the animal's nose and mouth... The pores act as electroreceptors detecting prey moving in the electromagnetic field around the shark - but also for some reason rubbing them turns 'Jaws' into a sleeping baby.

Ms Zenato uses her ability to put the sharks in a sleepy state to educate other divers, remove parasites and even take out fishing hooks caught in their mouths.

Mr Meier, a commercial photographer who specialises in underwater, nature and travel, said he hoped to raise awareness of the plight of sharks. He said: 'We kill millions of sharks every year, with the majority of those having their fins cut off while still alive and then thrown back into the water to die a slow, agonising death. 
I remember reading reports years ago of surfers or swimmers defending themselves from sharks by hitting the shark on the nose; it was said to be an effective deterrant.  Perhaps this report offers a biologic basis for that observation.


  1. Do all shark whisperers cast odd shadows?

  2. There was a horrible report of several thousands of sharks being killed for their fins off the coast of the Galapagos Islands. http://www.guardian.co.uk/environment/2011/oct/19/shark-massacre-colombia

    Someone should start a rumor that eating just one bowl of shark fin soup will make a person impotent for life! It seems that's about the only way to stop such incredible greed -- cut off the market for it.

  3. Shark "finning" is an abomination far as I'm concerned.

    Don't get me wrong: I eat meat. BUT that doesn't mean I feel I can do anything I want to a living thing capable of feeling pain.

    If you're gonna eat an animal, kill it as fast and humanely as possible and use as much of it as possible. Maiming something and then tossing it away to die slowly is unbelievable.

  4. Check out the video. Then end is worth waiting for.


  5. Haven't heard the punching trick...
    I thought the first step was you were supposed to jam your hand into the back of their open mouths to gag 'em.
    Then gouge out the eyes with your stump.
    Har har har har

  6. expat - WOW, just WOW. I've added the video and bumped the post to the top of the blog.

    Thank you.

  7. I think Orcas may use their own version of the technique to feed on Great Whites

  8. The sound track doesn't really fit the video, but the song is fabulous.

    What a kick it must be to have those fearsome creatures literally in the palm of your hand...

    --Swift Loris

  9. "Ampullae of Lorenzini" sounded familiar when I was looking at the purchase of a Shark Shield and reminded me of this post. I recently bought a boat and have been doing a bit of snorkeling and "aquanaut"ing. My family and I have seen quite a few small sharks around and are a bit nervous that there might be larger ones around the corner. Thus my looking at the Shark Shield. Apparently the Ampullae of Lorenzini are very sensitive to certain electrical fields. It is this sensitivity and apparently great pain produced by electrical fields that is the basis for this device being used as a shark deterrent. (The testimonial page on their website has page after page of personal accounts of encounters with sharks while wearing the device.) It must be that electrical stimulation of the ampullae is painful but physical stimulation overcomes that pain and acts like a sedative. Not unlike nose hairs being sensitive to minor irritations yet able to handle someone picking his or her nose. It's to do with thresholds. Nevertheless I'd rather irritate a shark's nose hairs than rub it while I am in its domain. By the way, good tip on saving text before attempting to sign in. I just lost this comment (but saved it) whilst signing in.


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