Carcinisation (or carcinization) is an example of convergent evolution wherein a crustacean evolves actual into a crab-like make from a non-crab-like make. The term changed into once launched into evolutionary biology by L. A. Borradaile, who described it as “one in every of the rather heaps of attempts of Nature to conform a crab”.
Carcinisation is believed to have happened independently in as a minimal 5 groups of decapod crustaceans, most particularly king crabs, which most scientists think evolved from hermit crab ancestors. The different examples are the family Porcellanidae or porcelain crabs (that are carefully connected to squat lobsters), the hairy stone crab Lomis hirta, the coconut crab Birgus latro, and fair crabs (Brachyura). A prehistoric example is the extinct crustacean advise Cyclida, which evolved their crab-like morphology sooner than the existence of fair crabs.
The example of king crabs (family Lithodidae) evolving from hermit crabs has been particularly well studied, and evidence of their biology supports this notion. As an instance, most hermit crabs are asymmetrical, so as that they match well into spiral snail shells; the abdomens of king crabs, despite the incontrovertible reality that they attain no longer utilize snail shells for shelter, are also asymmetrical.
An distinctive make of carcinisation, termed “hypercarcinisation”, is seen in the porcelain crab Allopetrolisthes spinifrons. Apart from the shortened physique make, A. spinifrons also reveals same sexual dimorphism to that seen in fair crabs, the place males have a shorter pleon than females.