Meeting Abstract

P2.46  Monday, Jan. 5  The dissociation of the apical sensory organ of Phestilla sibogae during metamorphosis RUIZ-JONES, G.J.*; HADFIELD, M.G.; Chaminade University of Honolulu, Honolulu guadalupe.ruiz-jones@student.chaminade.edu

The apical sensory organ of Phestilla sibogae undergoes radical morphological changes during metamorphosis. At the beginning of metamorphic induction (1 hour) the ASO is complete with 5 serotonergic neurons (2 type II parampullary and 3 type I parampullay) and 5 ampullary neurons filled with sensory cilia. As metamorphosis proceeds the ASO and serotonergic nerve fibers originating from the ASO that innervate the velum begin to dissociate. The 5 serotonergic neurons of the ASO are no longer present once the velum is lost. The 5 ampullary neurons of the ASO appear morphologically different by the third hour of metamorphosis. By the eighth hour of metamorphosis the ampullary neurons have lost their connections and begun to dissociate. It is evident that by the third hour, in larvae that have lost their velum, the ASO no longer exists. However, it is interesting that the ASO does persist up to the eighth hour of metamorphosis in larvae that have not lost their velum.