Goldenarcher1328
New Member
As an owner of chameleons it has fascinated me that they're tongues are used with such speed, grace and precision. After doing my research, i've decided to put up a post on what i have learned and how i see it. Feel free to pitch in more info or correct me if i have something backwards. 
At the back of a chameleons mouth there is a "U" shaped bone called the Hyoid bone, attached at the center of this bone is a long, cartilaginous tapering horn called the Hyoid horn. A chameleon's tongue is hollow and sits sheathed over this Hyoid horn.
When a Chameleon is not taking aim at its prey, the tongue along with this mechanism is located at the bottom of the mouth, with the base seated in the throat just behind the head, as seen here http://www.chamaeleon-terraristik.de/assets/images/cSkelett8.jpg . Upon locating prey, a chameleon will "take aim" Positioning the head in such a manner that it is aligned with the prey item, the chameleon meanwhile is shifting the whole mechanism forward while muscles raise the Hyoid bone above the lower jaw bone.
At this point in time the chameleon is ready to fire.
The tongue of a chameleon is made up of three basic parts according to most people. The Tip of the tongue which is a larger, sticky pad used for "grabbing" prey items. The center of this sticky pad is tense, allowing the outer edges to flow around the prey item when contact occurs. This creates a vacuum effect, effectively suctioning the prey item to the tongue.
Next we have two types of muscles, Accelerator muscles which are responsible for propelling the tongue down along the hyoid horn and Retractor muscles which are responsible for reeling in the tongue after firing.
The muscles used to accelerate the tongue are much like sphincters. Each ring of muscle squeezes against the hyoid horn, slipping down along the tapered horn. Because the horn is tapered, the can further tighten by simply moving further down the horn, thus propelling the tongue down the horn. Ontop of this sphincter like muscle there is an elastic like collagen which is wrapped along the hyoid horn, this is attached at one end, to the hyoid horn and at the other end, to these accelerator muscles this acts as a biological "slingshot". Imagine a rubber band stretched along a pencil, at rest the elastic like collagen is like this rubber band pulled all the way back, upon releasing the rubber band, it is propelled off the tip of the pencil along with anything attached to the rubber band. Once the tongue is fired, the chameleon must simply "follow through" with the shot and wait for impact.
Chameleons will generally aim for the head of the prey to minimize the risk of a struggle. Upon retraction of the tongue the chameleon will close its eyes to prevent injury.
Retractor muscles function in a very different way, because speed is not essential to reeling in prey, you will notice that a chameleon's tongue will often collapse upon retrieval. The retracting muscles of a chameleons tongue do not act in the same ways as the accelerators, but act more like a slinky. When fully extended, the retracting muscles are smooth and in their furthest outward position. Upon retrieval, the accelerator muscles relax, allowing themselves to slip back onto the hyoid horn. At the same point in time, the fully extended Retractor muscles begin to contract and pull the tongue back into its resting position.
Now, Imagine all that in 1/16th of a second!
Enjoy!
At the back of a chameleons mouth there is a "U" shaped bone called the Hyoid bone, attached at the center of this bone is a long, cartilaginous tapering horn called the Hyoid horn. A chameleon's tongue is hollow and sits sheathed over this Hyoid horn.
When a Chameleon is not taking aim at its prey, the tongue along with this mechanism is located at the bottom of the mouth, with the base seated in the throat just behind the head, as seen here http://www.chamaeleon-terraristik.de/assets/images/cSkelett8.jpg . Upon locating prey, a chameleon will "take aim" Positioning the head in such a manner that it is aligned with the prey item, the chameleon meanwhile is shifting the whole mechanism forward while muscles raise the Hyoid bone above the lower jaw bone.
At this point in time the chameleon is ready to fire.
The tongue of a chameleon is made up of three basic parts according to most people. The Tip of the tongue which is a larger, sticky pad used for "grabbing" prey items. The center of this sticky pad is tense, allowing the outer edges to flow around the prey item when contact occurs. This creates a vacuum effect, effectively suctioning the prey item to the tongue.
Next we have two types of muscles, Accelerator muscles which are responsible for propelling the tongue down along the hyoid horn and Retractor muscles which are responsible for reeling in the tongue after firing.
The muscles used to accelerate the tongue are much like sphincters. Each ring of muscle squeezes against the hyoid horn, slipping down along the tapered horn. Because the horn is tapered, the can further tighten by simply moving further down the horn, thus propelling the tongue down the horn. Ontop of this sphincter like muscle there is an elastic like collagen which is wrapped along the hyoid horn, this is attached at one end, to the hyoid horn and at the other end, to these accelerator muscles this acts as a biological "slingshot". Imagine a rubber band stretched along a pencil, at rest the elastic like collagen is like this rubber band pulled all the way back, upon releasing the rubber band, it is propelled off the tip of the pencil along with anything attached to the rubber band. Once the tongue is fired, the chameleon must simply "follow through" with the shot and wait for impact.
Chameleons will generally aim for the head of the prey to minimize the risk of a struggle. Upon retraction of the tongue the chameleon will close its eyes to prevent injury.
Retractor muscles function in a very different way, because speed is not essential to reeling in prey, you will notice that a chameleon's tongue will often collapse upon retrieval. The retracting muscles of a chameleons tongue do not act in the same ways as the accelerators, but act more like a slinky. When fully extended, the retracting muscles are smooth and in their furthest outward position. Upon retrieval, the accelerator muscles relax, allowing themselves to slip back onto the hyoid horn. At the same point in time, the fully extended Retractor muscles begin to contract and pull the tongue back into its resting position.
Now, Imagine all that in 1/16th of a second!
Enjoy!
