Autodax: Feeding in Hydromantes platycephalus

Feeding in Hydromantes platycephalus

Salamanders of the genus Hydromantes in the family Plethodontidae have the longest tongues of any salamanders, by absolute as well as relative measure. This genus of salamanders can extend the tongue more than half the length of the body, excluding the tail. That's a 5cm long tongue in quite a small animal! The species in this movie is Hydromantes platycephalus, which is from the Sierra Nevada mountains of California. It lives at high elevation in rocky areas along streams and at the edges of snow packs. It uses its webbed feet to climb vertical rock faces, and its long tongue to pick off its insect prey. Notice that it moves slightly backward from the recoil of the tongue being launched. The rate of this movie is 2250 images per second.

Below is an animation of the projection of the tongue skeleton (the hyobranchial apparatus) in Hydromantes, which consists of seven cartilaginous elements linked by flexible joints. The frame of reference for this simulation is the tongue, which is why the salamander appears to move backwards. The tongue rests at the tip of the central element at the far right. Notice how the long elements (epibranchials) are flexible and conform to the pathways within the neck and head of the salamander as they move forward and how the joints flex as the apparatus folds into a compact projectile.