Brachycephalus is a genus of tiny Brazilian frogs commonly called pumpkin toadlets. The various species of these frogs average around a half-inch long! These are such small vertebrates that they suffer from a common problem of miniaturization, in that certain organs are just too small to do the job we assume they are for. See, pumpkin toadlets are very bad at the one thing frogs are known for: jumping. They can take off just fine, but land in a fairly haphazard (and comical) way.
A new study tells us that the culprit is the inner ear. The semicircular canals in our ears are responsible for our sense of balance, direction, and orientation. In a pumpkin toadlet, these semicircular canals are about a half a millimeter across, which runs up against the limits of fluid dynamics in biological systems. The frogs, therefore, cannot orient themselves during a jump, so they don't know when or where they will land. On the up side, they are very lightweight and can handle such a fall. Why did these frogs evolve in such a way? Maybe because their miniature size was a greater benefit for their environmental conditions than the loss of balance was a drawback. You can read more about these tiny tipsy toads at Gizmodo.
(Image credit: Ribeiro LF, Bornschein MR, Belmonte-Lopes R, Firkowski CR, Morato SAA, Pie MR.)
#frog #pumpkintoadlet #miniaturization #semicircularcanals #Brachycephalus
