Tuesday, April 17, 2012

Mantis Shrimp

     Joe Sugura and two of his friends just got back from Water Cay Lodge on Grand Bahama Island. They had a great trip with lots of bones including some big bones (up to 27 inches at the fork). Joe also hooked (albeit briefly) an approximately 18 lb. permit, but what was really cool was what a large bonefish disgorged when he landed it. Apparently, the bonefish had eaten, but not completely swallowed this shrimp and it was disgorged virtually intact. I think this is a tan or cream mantis shrimp. If someone knows differently, please let me know.

     In all the years I have been bonefishing, I rarely see mantis shrimp on the flats and I have seen only one other mantis shrimp actually inside the gut of a bonefish. In the stomach of almost all of the shark-killed bonefish that I have examined, I have seen mostly tan crabs and the rare worm or tiny shrimp (less than one inch). I did see in a big bone's stomach what I thought to be an olive mantis shrimp on Abaco many years ago. It was fairly well digested so it was hard to say for certain what it was. 
     This photo of the mantis shrimp makes the old adage "any color will work in the Bahamas as long as it is tan" resonate a bit more eh?!!  

     Also look at the fly in the bone's mouth. It's not hard too see why he jumped on it after his snack of mantis shrimp! 
     Thanks Joe for taking the photo and passing it on!! This info should generate some interesting patterns!


  1. It's hard to tell from the photo but that might be either a thalassinidae (ghost shrimp family) or a stomatopod (mantis shrimp). One way to tell is to inspect the second set of legs. Mantis' will have either "smashers" (which look like boxing gloves or spears (which look like a praying mantis' graspers). Ghost shrimps will have tiny claws. The rest of their bodies look very similar without magnification. I think ghost shrimp are much more common in the Bahamas and on sand flats. Although mantis shrimps do occur in the Bahamas, the ones that live in sand are almost always the spearing type. The smashers tend to live in more rocky / coral environments where they find burrows. Another clue is that most mantis shrimp are brightly colored whereas the ghost shrimp are usually pale sandy colors.

    I really should get over to the UC Museum of Paleontology and check out their stomatopod exhibit. They're fascinating critters.

  2. Thanks Doug.
    I can always count on you for good info!
    I'll pass this info on to Joe Sugura!
    The Bahamians call mantis shrimp "thumb smashers". I have known a few old time guides that can call bonefish out of the mangroves by popping water with their fingers. The bonefish think it is a mantis shrimp and comes to investigate. I've seen it done a couple times. Once by the guide of Crazy Charlie fame.
    There is some evidence that the smasher on a mantis shrimp reaches incredible speeds due to a bubble of air that is produced upon release of their murderous appendage. Apparently, a vacuum is produced causing sonic cavitation. This is all about the physics of water pressure and vapor pressure.
    The strike causes the same or similar effect caused by the space shuttle at reentry. Cavitation is an extremely potent fluid dynamic phenomenon which occurs when you have areas of water moving at extremely different speeds. And when this happens, it can cause areas of very low pressure, which results in the water literally vaporizing. And when that vapor bubble collapses, it emits sound, light and heat, and it's a very destructive process.
    If this is true, this animal's appendage reaches the highest speeds in the animal kingdom.
    Look at this video if interested:
    Doug, do you know anything more about this?

  3. Mantis Shrimp rule here in Hawaii. On many flats they are the preferred Bonefish food item. www.BonefishHawaii.com

    1. Hi Captain Rick,
      Nice website and man you have some BIG bones!!

  4. Hey Scott - That is consistent with what I've read about how the "smasher" type of mantis shrimp attack their prey (and enemies too I think). I've read about people's fingernails being split open by large mantis shrimp. Mantis shrimp are one of the coolest, and most unique animals we can find on the flats. The galleries on this site are really nice: http://www.blueboard.com/mantis/

    I'm pretty sure the "rainbow mantis" pictured on page 2 of the galleries is the one Coach Duff and I tried to catch on the reef flat in Hawaii. It was bright yellow when we found it. Neither of us had the guts to try to grab it by hand.

    1. ...and that is why you still have thumbs and/or legs Doug!!...
      given the tiger shark on Andros!

  5. Anyone know what colored eyes the Bahamian mantis shrimp have? Ververka makes his out of nylon and Charlie Craven made his Junk with green eyes. Thanks.