Meeting Abstract

101.9  Wednesday, Jan. 7  High-speed video reveals capture of particles by direct interception by cilia during feeding of a gastropod veliger. ROMERO, M. R.*; KELSTRUP, H. C. P.; STRATHMANN, R. R.; California State Univ., Los Angeles; University of Washington; University of Washington MelissaRRR20@hotmail.com

Ciliary feeding varies in arrangement of ciliary bands, mechanisms of capture, and concentration of food. Some larvae use opposed parallel bands of preoral (prototroch) and postoral (metatroch) cilia. Hypotheses for the mechanism of particle capture include filtration by adhesion to a cilium (direct interception), but unequivocal evidence for this mechanism has been lacking. High-speed video recordings of gastropod veliger larvae of Lacuna vincta indicated direct interception by prototrochal cilia. Adhesion between cilium and particle was seen when a prototrochal cilium tugged a diatom chain into the food groove while in contact with one part of the chain. In several recorded events, a prototochal cilium overtook a particle during its effective stroke; then moved the particle inward with its recovery stroke and the particle subsequently moved to the food groove. Captures varied, however. In some cases the particle was intercepted multiple times in one capture event. In others several cilia passed a particle without interception. Particles occasionally remained in the area of recovery strokes, indicating retention without adhesion to a cilium. In three events, a particle lost from a prototrochal cilium was intercepted and moved into the food groove by metatrochal cilia. Particles as wide as or wider than the food groove were captured and transported but not ingested.