Apoptotic elimination of neuronal cells during metamorphosis of Hydractinia echinata Seipp, S.; Schetter, E.; Schmich, J.; Plickert, G.; Leitz, T. Zoology (Jena) 105(Suppl 5): 14 2002 0944-2006 https://eurekamag.com/research/034/429/034429855.php