Fission (biology)

Fissiparie describes the ability of certain animals to generate a new organism from severed body parts. This term is best known in connection with the asexual reproduction of some echinoderms. Thus, for example starfish on the rejection of their arms can multiply, with each arm of a new starfish can occur.

Special

Fissiparie as a form of reproduction is known in only 26 of the species of starfish described about 1600, where the mechanism differs greatly between species. In particular, smaller specimens from a population seem to use this form of reproduction. It has been observed that reproduction occurs mainly through Fissiparie under extreme environmental conditions, such as extreme temperature, lack of oxygen, increased salinity ( K ). Experimentally, Fissiparie be triggered eg by transection of the nerve rings at two points or by electric current. Natural Fissiparie has even been observed in a variety of Luidia in the larval stage.

Except for starfish Fissiparie is still known in other echinoderms: In crinoids, sea urchins, sea cucumbers and brittle stars. In addition Fissiparie was in many invertebrate animals, for example in bryozoans, cnidarians, segmented worms, belts worms, acorn worms ( Hemichrodata ), horseshoe worms, worms and spray flatworms described.

In unicellular organisms, this form of reproduction by regeneration as Schizotomie or schizogony is known.

Swell

• Reproduction
• Zoology