Evisceration (autotomy)

Evisceration, often considered a form of autotomy, refers to the expulsion of internal organs by an animal, typically as a defensive mechanism against predators or unfavorable environmental conditions. While "autotomy" strictly refers to the self-amputation of a body part, evisceration shares the characteristic of being a self-inflicted action for survival. However, instead of limbs or appendages, evisceration involves the ejection of internal organs.

The organs expelled can vary depending on the species, but commonly include parts of the digestive tract, such as the intestines, or respiratory organs. The process can be triggered by physical attack, stress, or changes in environmental conditions like temperature or salinity.

The expelled organs may be unpalatable or distracting to a predator, allowing the animal to escape. In some species, the eviscerated organs are regenerated over time.

Evisceration is observed in a variety of marine invertebrates, including sea cucumbers, starfish, and some mollusks. It is less common in vertebrates. The specific mechanisms and the extent of organ regeneration vary significantly between species.