Gyrinophilus is a hemidactyliine plethodontid, like Pseudotriton, which possesses an aquatic larval stage. All salamander larvae capture prey by suction feeding, in which the buccal cavity is expanded rapidly and water and prey are sucked in. The water is then expelled from the gill slits. This larval Gyrinophilus is capturing a tubifex worm. Note the large ventral expansion of the throat, which is accomplished by ventro-caudal swinging of the hyobranchial apparatus (which forms the tongue skeleton in the adult). The background grid is 5 mm.