Autotomy
[22][23][24] There are also examples in which salamanders will attack the tails of conspecifics in order to establish social dominance and decrease the fitness of competitors.
[28] Since the tail plays a significant role in locomotion and energy storage of fat deposits,[17][27] it is too valuable to be dropped haphazardly.
Many species have evolved specific behaviors after autotomy, such as decreased activity, to compensate for negative consequences such as depleted energy resources.
[31] There are also adaptations that help mitigate the cost of autotomy, as seen in the highly toxic salamander, Bolitoglossa rostrata, in which the individual will delay autotomy until the predator moves its jaws up the tail or holds on for a long time, allowing the salamander to retain its tail when toxicity alone can ward off predators.
[32] Regeneration is one of the highest priorities after autotomy, in order to optimize locomotor performance and recoup reproductive fitness.
While regenerating their tails, caudal autotomy is restored at an energetic cost that often hinders body growth or intraspecies interactions.
[26][33] Fossils of reptiles possessing the ability to autotomize that are not within the lizard family have been found that date back to the Late Carboniferous and Early Permian, belonging to the groups Recumbirostra and Captorhinidae.
[38] These and other species of rodent are also known to exhibit a so-called "false caudal autotomy," whereby the skin on the tail slides off with minimal force, leaving only the bare vertebral structure.
[39] Examples of species possessing this ability are cotton rats (Sigmodon hispidus), eastern chipmunks (Tamias striatus), and degu (Octodon degus).
Autotomy serves either to improve the chances of escape or to reduce further damage occurring to the remainder of the animal such as the spread of a chemical toxin after being stung.
[44] Young specimens of two Elysia species, E. atroviridis and E. marginata, can regenerate their whole parasitised body from their head which may have evolved as a defence-mechanism against internal parasites.
These sea slugs are known to be able to conduct photosynthesis via incorporating chloroplasts from algal food into their cells which they use to survive after separation from their digestive system.
Harvesting is accomplished by removing one or both claws from the live animal and returning it to the ocean where it can regrow the lost limb(s).
[50] The autotomy reflex in crustaceans has been proposed as an example of natural behaviour that raises questions concerning assertions on whether crustaceans can "feel pain", which may be based on definitions of "pain" that are flawed for lack of any falsifiable test, either to establish or deny the meaningfulness of the concept in this context.
The male of Nephilengys malabarensis from Southeast Asia breaks off his pedipalp when transferring sperm and plugs the female's genital opening, after which the palp keeps pumping.
[57] Although it is widely believed that a worker honey bee can sting only once, this is a partial misconception: although the stinger is barbed so that it lodges in the victim's skin, tearing loose from the bee's abdomen and leading to its death, this only happens if the skin of the victim is sufficiently thick, such as a mammal's.
