Starfish by the starfish in an escape response. The loss of parts of the body is achieved by the rapid softening of a special type of connective tissue in response to nervous signals. This type of tissue is called catch connective tissue and is found in most echinoderms. An autotomy-promoting factor has been identified which, when injected into another starfish, causes rapid shedding of arms. The lifespan of a starfish varies considerably between species, generally being longer in larger forms and in those with planktonic larvae. For example, "Leptasterias hexactis" broods a small number of large-yolked eggs. It has an adult
Starfish Devonian and late Permian, the blastoids were wiped out and only a few species of crinoids survived. Many starfish species also became extinct in these events, but afterwards the surviving few species diversified rapidly within about sixty million years during the Early Jurassic and the beginning of the Middle Jurassic. A 2012 study found that speciation in starfish can occur rapidly. During the last 6,000 years, divergence in the larval development of "Cryptasterina hystera" and "Cryptasterina pentagona" has taken place, the former adopting internal fertilization and brooding and the latter remaining a broadcast spawner. The scientific name Asteroidea was given