How does a lizard lose its tail?
Certain animals voluntarily shed a body part in response to attempted predation. Lizards losing their tails when they are pulled by a predator is well known. This self-amputation is called autotomy.
The severed tail continues to wiggle for about 30 minutes. Studies have shown that the severed tail follows an elaborate repetitive and diverse motion, which includes flips up to 3 cm in height. The wiggly motion very often distracts the attention of the predator, thus enabling the lizard to escape.
Now, researchers at Aarhus University have found the answer to what allows lizards to shed their tails easily. They found that tail autotomy occurs at preformed horizontal fracture planes. In the case of tail autotomy within the vertebra, the tail gets fractured or split at a distinct preformed area of weakness. Studies have shown that lizards aid the process of autotomy by “contracting muscles around the fracture planes”.
The muscle contractions are supposed to “facilitate splitting of the skin and muscles to complete the release of the tail”.
According to their findings published in December 2012 in the journal PLOS ONE, the mechanism of tail autotomy in Tokay gecko is determined by pre-formed ‘dotted lines’ in the fracture planes, which are maintained by adhesion and microstructures seen at the terminal end of the muscle fibres also likely play a role in releasing the tail.
The pre-formed fracture surfaces are found at specified intervals all along the lizard’s tail.
