Echinoderm reproduction is asexual, which means it takes place within the organism itself. It involves the division of the body into two or more parts (fragmentation) and the regeneration of missing parts.
Fragmentation and regeneration require a body wall that can be torn and an ability to seal the resultant wounds. Fragmentation is a common method of reproduction among echinoderms. Asteroids and holothurians are two species known to reproduce by way of fragmentation. In some of these species, sexual reproduction does not occur at all.
Sea lilies, starfish and brittle stars are examples of echinoderms that have a developed ability to regenerate. They can all grow new arms if existing ones are ripped or broken off.