Autotomy

Lizard tail

Autotomy (from the Greek. Autós - himself and tomé - cut-off) - rejection by the animal itself, when irritated, of any organ or limb.

So, for example, the lizard , pressed by the tail, breaks it off in the middle of the vertebra and leaves, the octopus with a sharp contraction of muscles tears off its tentacle, captured by the enemy, the crayfish - claws, insects and spiders - the legs for which they are caught, the needle-like mice - the skin. Holothuria together with silt eject through the anus the intestines or the Cuvier organs , causing thereby clouding of water, and the latter, in addition, envelop the predator, thereby immobilizing it.

An autotomy serves the animal as a defense against attack: by losing a separate organ, the animal saves life. However, this phenomenon may also be due to the deterioration of environmental conditions, for example, in holothurians with a lack of oxygen and an increased need to lay eggs. The same thing happens in some other animals: for example, hydra lose their tentacles, and turbellaria lose their eyes. In this case, the phenomenon may relate to degeneration .

Lost organs in animals are then restored (see regeneration ).