Autotomy of the posterior foot in Agaronia (Caenogastropoda: Olividae) occurs in animals that are fully withdrawn into their shells
Journal of Molluscan Studies
Autotomy is the active shedding of a body part which occurs in a variety of emergency situations including attacks by predators (Stasek, 1967; McVean, 1975; Maginnis, 2006). The immediate advantage of autotomy – surviving an otherwise deadly attack – comes at a price, which may include physical, energetic, behavioural and reproductive costs (Cooper, 2003; Maginnis, 2006). While the evolutionary and ecological consequences of autotomy have been studied most thoroughly in lizards (Clause & Capaldi, 2006; Bateman & Fleming, 2009), the phenomenon also is known from numerous invertebrate taxa, where it involves a wide variety of body structures (Fleming, Muller & Bateman, 2007). In the Mollusca autotomy occurs in bivalves, scaphopods, gastropods and cephalopods; the older literature was summarized by Stasek (1967). Several additional cases have been reported more recently, mostly without detailed information on mechanisms and ecological implications (e.g. Warmke & Almodóvar, 1972; Hughes & Emerson, 1987).
In gastropods various body parts may be autotomized. In nudibranchs autotomy of cerata (outgrowths of the body wall that increase the body's surface-to-volume ratio and facilitate gas exchange) in response to attacks by predatory arthropods and the prey's subsequent escape have been reported repeatedly (Bickell–Page, 1989; Piel, 1991; Miller & Byrne, 2000). Autotomy of the mantle margin has been observed in many nudibranchs (reviewed by Stasek, 1967) and one prosobranch (Liu & Wang, 2002). Mantle autotomy generally appears to be a relatively slow process (Stasek, 1967) and no direct observations of predator–induced mantle autotomy have been published so far. The third category is the autotomy of parts of the foot, usually the posterior portion (‘tail’), which has been observed in all major groups of gastropods (Stasek, 1967). In terrestrial shell–less slugs, ‘tail’ autotomy has been interpreted as a defensive response against predators that attack …
Samantha D. Rupert and Winfried S. Peters (2011).
Autotomy of the posterior foot in Agaronia (Caenogastropoda: Olividae) occurs in animals that are fully withdrawn into their shells. Journal of Molluscan Studies.77 (4), 437-440. Oxford Journals.