Home | Field studies and notes | Research Update – Perret’s Night Frog (Astylosternus perreti) Defends Itself with Skin-Sheathed Claws

Research Update – Perret’s Night Frog (Astylosternus perreti) Defends Itself with Skin-Sheathed Claws

Harvard biologist David Blachurn knew he was onto something unusual when a benign-looking frog he was examining in Cameroon, West Africa kicked out and left him with a bleeding cut.  Unusual indeed – an article  (23 August 2008) in Biology Letters describes the hidden claws of Perret’s night frog as the only vertebrate claws known to break through the skin in order to become functional.  Some, or possibly all, of the other 10 frogs within the genus Astylosternus are also equipped with skin-covered claws on their toes (the fingers are clawless).

Suriname Toad with Eggs on BackThe frog’s sharp, curved claw is actually the last bone of the toe, and pierces the toe’s skin when a specific tendon is flexed.  It is assumed that the claw retracts after use and the skin heals, but further study is needed.  Other amphibians that experience “self-inflicted” wounds include the Surinam toads, Pipa spp., whose young push through the skin of the female’s back when ready to swim off on their own and the ribbed newt, Pleurodeles waltl.  The ribs of this newt pierce the skin of the back, carrying toxins with them, when the animal is threatened.

Despite the massive trauma caused by the emergence of 80+ fully formed little frogs, the skin of breeding Surinam toads (P. pipa) under my care appeared well-healed within 24 hours.  I’m sure there are some compounds that may be of medical use to people hidden in the body chemistry of this and other amphibian species.

Of course, people living within the habitat of Perret’s night frog have long known of its odd defense and even utilize specially-constructed spears when hunting it, to avoid being injured.

The only other frogs known to have claws are members of the family Pipidae – the various African clawed and dwarf African clawed frogs.  I have observed both putting their claws, which are always exposed, to interesting uses (more to come in future articles).

You can read more about this frog and related species at:

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  1. Pingback: Research Update – Perret’s Night Frog (Astylosternus perreti) Defends Itself with Skin-Sheathed Claws | Pet Reptile Supplies

About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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