Americobdella valdiviana is a predator and has only rudimentary jaws. Because of these features, it was originally classified as an erpobdellid leech. A. valdiviana is grey-coloured on the dorsal side with a yellowishventral side. Whethereyes are present in this species is a matter of debate. While Philippi originally described Americobdella valdiviana as having no eyes, other authors have indicated that eyes are indeed present.