Results 1 to 4 of 4

Thread: The frog that pokes its bones through the skin to make claws

  1. #1
    Super Moderator twitchy2.0's Avatar
    Join Date
    Aug 2008
    Location
    Milliways
    Posts
    55,679

    Default The frog that pokes its bones through the skin to make claws

    'Horror frog' breaks own bones to produce claws
    "Amphibian horror" isn't a movie genre, but on this evidence perhaps it should be. Harvard biologists have described a bizarre, hairy frog with cat-like extendable claws.

    Trichobatrachus robustus actively breaks its own bones to produce claws that puncture their way out of the frog's toe pads, probably when it is threatened.

    David Blackburn and colleagues at Harvard University's Museum of Comparative Zoology, think the gruesome behaviour is a defence mechanism.

    The researchers say there are salamanders that force their ribs through their skin to produce protective barbs on demand, but nothing quite like this mechanism has been seen before.
    The feature is also found in nine of the 11 frogs belonging to the Astylosternus genus, most of which live in Cameroon.

    Instant weapon

    "Some other frogs have bony spines that project from their wrist, but in those species it appears that the bones grow through the skin rather than pierce it when needed for defence," says Blackburn.

    At rest, the claws of T. robustus, found on the hind feet only, are nestled inside a mass of connective tissue. A chunk of collagen forms a bond between the claw's sharp point and a small piece of bone at the tip of the frog's toe.

    The other end of the claw is connected to a muscle. Blackburn and his colleagues believe that when the animal is attacked, it contracts this muscle, which pulls the claw downwards. The sharp point then breaks away from the bony tip and cuts through the toe pad, emerging on the underside.

    Hirsute horror

    The end result may look like a cat's claw, but the breaking and cutting mechanism is very different and unique among vertebrates. Also unique is the fact that the claw is just bone and does not have an outer coating of keratin like other claws do.

    Because Blackburn has only studied dead specimens, he says he does not know what happens when the claw retracts - or even how it retracts. It does not appear to have a muscle to pull it back inside so the team think it may passively slide back into the toe pad when its muscle relaxes.

    "Being amphibians, it would not be surprising if some parts of the wound heal and the tissue is regenerated," says Blackburn.

    Males of the species, which grows to about 11 centimetres, also produce long hair-like strands of skin and arteries when they breed (see image). It is thought that the "hairs" allow them to take in more oxygen through their skin while they take care of their brood.

    Spiky snack

    In Cameroon, they are roasted and eaten. Hunters use long spears and machetes to kill the frogs, apparently to avoid being hurt by their claws.

    "This is an incredible story," says Ian Stephen, curator of herpetology at the Zoological Society of London, UK. "Some frogs grow spines on their thumbs during breeding season, but this is entirely different."

    "For me, it highlights the need for a lot more research on amphibians especially in light of the threat of mass extinctions," he adds.

    The existence of frogs with erectile claws like cats was first described by Belgian zoologist George Boulenger in 1900 in frogs found in the French Congo, now the Republic of Congo.
    'Horror frog' breaks own bones to produce claws - life - 28 May 2008 - New Scientist


    The frog:



    OK, the REAL frog:



    they have the same sideburns too.
    As Canadian as possible under the circumstances

    --------------------------------------------------------------------------------------------------------------------


    "What's traitors, precious?" -- President Gollum

  2. #2
    Elite Member Rondette's Avatar
    Join Date
    Jan 2006
    Location
    Between uncertainty and acceptance
    Posts
    4,544

    Default

    lol at the Wolverine compo.

    I wanna see it with it's claws out!

  3. #3
    Elite Member panda's Avatar
    Join Date
    Oct 2005
    Location
    Hotlanta, GA
    Posts
    1,937

    Default

    nature is awesome!

    Petunia Pearl

  4. #4
    Elite Member Honey's Avatar
    Join Date
    Dec 2006
    Location
    England
    Posts
    59,915

    Default

    Amazing

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 47
    Last Post: September 27th, 2008, 01:31 PM
  2. Celebrity skin and bones
    By NicoleWasHere in forum Weight
    Replies: 2
    Last Post: May 4th, 2008, 07:42 PM
  3. Replies: 14
    Last Post: March 25th, 2008, 01:25 PM
  4. Does the make up that says it clears your skin actually work?
    By ChangingEventually in forum Beauty and Skincare
    Replies: 4
    Last Post: February 20th, 2007, 09:39 AM
  5. Kate Bosworth skin and bones
    By teeyiu in forum Weight
    Replies: 24
    Last Post: October 7th, 2006, 01:33 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •