Meeting Abstract

116.9  Monday, Jan. 7  Comparative Time-Lapse Studies of Coughing Calcareous Sponges BOND, C; Greensboro College, North Carolina bondc@greensboro.edu

Despite their lack of muscles and neurons, sponges are capable of propagated contractile events, known as contractile waves. These contractions have been studied mostly in demosponges with the typical leuconoid canal design. This present study presents novel time-lapse examinations of contractions in live calcareous sponges with simpler canals: Leucosolenia botryoides (asconoid canals) and Sycon clliata (syconoid canals). Particular attention was paid to contractile events here termed “debris coughs”, in which clouds of debris were ejected from excurrent oscules during a contractile wave. Debris coughs occurred in both asconoid and syconoid sponges: syconoid sponges were observed to cough more frequently and in apparently greater volumes than was seen in asconoid sponges. Debris fields (presumably ejected by a cough) also were seen occasionally with Sycon sponges: these deposits were composed of small round cells of uncertain nature, but they were in the same size range as choanocytes. Putative ingredients of the ejected debris clouds could be sponge cells and/or the residue of organisms (victims of predation and filtration) trapped and consumed in the canals of these highly spiculose sponges.