Crested Gecko. Photo by author

Sunday, April 10, 2011

A Gecko With Five Hands?...

All the geckos found in the genus Rhacodactylus have prehensile tails.  This adaptation gives them the ability to grab objects such as twigs and vegetation (Black, 18).  In the image below my one crested gecko can seen hanging their entire body from the pen.  The tail gives them extra support in reaching difficult places and incase of falling they have a better chance in grabbing something in the fall.  Increasing their chance in survival in the wild, due to them being an arboreal species and spending most of there time in the trees.


On the tip of the tail is a flattened pad with lamellae located on the underside.  Lamellae are the structures that give them the abiltiy to climb walls and glass.  The pads give them better grip in their tail strength.  When handling crested geckos and other rhacodactylus you can feel the pad "sticking" to your skin.  Another adaptation that the tail has that is common a lot in the lizard world is the ability to drop their tail when they feel threatened also called autotomy.  Most geckos have fracture planes between each tail bone, making it easy to detatch their tail without losing the entire tail, which then can be regenerated.  However with some species of rhacodactylus they cannot regenerate lost tails.  Crested geckos only have one fracture plane located at the base of the tail making them unable to regenerate a lost tail.  Most geckos seen in the wild are missing tails due to predators (Black, 18-19). 

In the wild they have only chance of using this defensive strategy in escaping from a predator, once they drop their tail they no longer have that multi-tooled tail.  Using their prehensile tail ability in climbing and used as support in their arboreal habitat, why do you guys think that once they lose their to tail they cannot regenerate it?  Why does this adaption exist for crested geckos in having only one fracture plane and not multiple like most other species?

2 comments:

  1. Do they never regrow their tail or is it only after adulthood? I would think, depending on the life expectancy, that it wouldn't grow back it's tail for saving energy or so that a predator does not have an extra long appendage that could be an easy target in order to snatch up the gecko.

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  2. I think the reason some geckos cannot regrow their tails has to do with the type of cells that are located in that area. Perhaps only having one fracture plane is why they don't regrow their tails. It is possible geckos with multiple fracture planes have special regenerative cells at each of these planes. Maybe the crested gecko doesn't regrow it's tail because it lacks the cells that encourage regrowth.

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