Troglomorphism

Troglomorphism is the morphological adaptation of an animal to life in the constant darkness of caves, characterised by features such as loss of pigment, reduced eyesight or blindness, and attenuated bodies or appendages. Several terms are used to describe troglomorphic animals, namely troglobitic, stygobitic or stygofauna, troglofauna, hypogean, or hypogeic.

Troglomorphism occurs in several animal species, with examples among molluscs, velvet worms, arthropods, fish, amphibians (notably cave salamanders) and reptiles. To date there are no examples of troglomorphic mammals or birds. Pickerel frogs are not considered to be part of this category due to their classification as trogloxenes or possibly troglophiles. The first Troglobiont to be described was Leptodirus hochenwartii.