Reproductive System
Typically, fertilization is external when it comes to echinoderms. Reproduction in most echinoderms occurs through the process of mass spawning. The females gather, releasing their gametes into the sea water around them. At the same time, the males release their gametes as well, and the two join, forming an echinoderm egg. (animal diversity.ummz.umich.edu) In some cases, such as in starfish, echinoderms can detach a part of their body and it will regrow into a completely new animal. (www.mesa.edu).