Eutely

Eutelic organisms have a fixed number of somatic cells when they reach maturity. The exact number is constant for any one species. Development proceeds by cell division until maturity; further growth occurs by cell enlargement only.

A mature gastrotrich, with visible cells on the surface. Further growth now occurs by cell enlargement only

Most eutelic organisms are small or even microscopic: examples include the nematodes like ascaris, gastrotrichs, rotifers, tardigrades and dicyemida.

Eutelic organisms cannot heal most wounds because they cannot build new cells to replace old cells. So they tend to be r-strategists. They often have many offspring. Gastrotrichs reproduce about once every three days.

Other websites

• List of eutelic animals and other eutelic websites