apodal

Apodal is an adjective used in biology to describe organisms that lack feet or legs. The term derives from the Greek apo- meaning without and podos meaning foot. In zoological usage, apodal describes animals that do not possess true feet or locomotive limbs at any life stage. The concept is commonly applied to legless reptiles and amphibians, as well as certain fishes. Examples include snakes (Serpentes), caecilians (Gymnophiona), legless lizards, and eels (Anguilliformes). Some of these species move by muscular contractions and body undulations rather than by feet, yet they remain apodal because they have no discrete feet.

The term is primarily used in taxonomic descriptions and morphological notes as a binary trait alongside the presence of legs. It does not imply the absence of all locomotory structures, since many apodal animals use alternative methods of movement. In fossil descriptions, apodal can indicate the absence of hind limbs in ancestral forms.

Synonyms or closely related terms include apodous, though usage varies by author. In contemporary biology, apodal is a specialized descriptor found in field guides, taxonomic revisions, and morphological databases.