What does autotomy mean?
Autotomy is the ability of certain animals to voluntarily shed or sever a part of their own body, most commonly as a means of escaping predators. The classic example is the lizard that drops its wiggling tail to distract an attacker while it flees; crabs and crayfish may release a trapped claw, and some starfish can discard an arm. Crucially, autotomy is not accidental injury but a controlled, reflexive process, and in many species the lost structure regenerates over time. Biologists distinguish specific forms such as caudal autotomy (loss of the tail). The word is chiefly scientific, appearing in zoology and ecology writing rather than casual conversation, and it derives from Greek roots meaning 'self' and 'cutting'. It is a striking reminder of the remarkable survival strategies found in the animal kingdom.
nounThe voluntary shedding or self-amputation of a body part by an animal, typically as a defensive mechanism, followed in many species by regeneration of the lost part.
- In zoology: the deliberate shedding of a body part (such as a tail or limb) by an animal, usually as a defense against capture, often followed by regrowth.
"When the lizard was seized by the tail, it escaped through autotomy, leaving the wriggling appendage behind as a distraction."
"Crayfish can cast off a claw through autotomy when a predator grabs it."
"The researchers measured how frequently autotomy occurred in gecko populations exposed to high predation."
Rarely pluralized since autotomy is usually treated as an uncountable process; the plural appears only when referring to multiple distinct instances or types across organisms.
"Caudal autotomies were recorded across several lizard species in the survey."
Some lizards can literally detach their own tails to escape predators — and then grow them back.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of autotomy
Autotomy comes from Greek elements: 'autos' meaning 'self' and 'tomos' meaning 'a cutting', so literally 'self-cutting'. The term was adopted into scientific English in the late nineteenth century, when biologists formalized the study of self-severing behaviors in reptiles, crustaceans, and echinoderms. It shares its roots with words like 'anatomy' and 'appendectomy', which likewise use '-tomy' to denote cutting.
How autotomy is actually used
A technical term used mainly in zoology, ecology, and biology; rare in everyday speech. It carries no emotional connotation and is used descriptively rather than figuratively.
Easily confused with autotomy
An automaton is a self-operating machine or robot, whereas autotomy is the biological process of an animal shedding its own body part.