SS1.08 Sensory Ecology, Neurophysiology and Behavior of Zooplankton
Date: Monday, June 10, 2002
Time: 4:00:00 PM
Location: Carson B
 
JakobsenHH, Western Washington University/Shannon Point Marine Center , Anacortes, USA, jakobsh@cc.wwu.edu
 
Escape of protists in predator generated feeding currents
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The ciliate Strobilidium sp. and two flagellates, Chrysochromulina simplex and Gymnodinium sp., were exposed to predator generated feeding currents and their escape responses were quantified using 2d and 3d video analysis. All three studied organisms responded by escaping at a defined distance to their predators. A critical threshold fluid deformation rate for escape of 3.6/s was estimated in a quantifiable siphon suction flow field for the ciliate Strobilidium sp.. Using previously published models and the critical deformation rate estimated in the siphon flow, the reaction distance of Strobilidium sp. to the copepod Temora longicornis was estimated. The estimated reaction distance of Strobilidium sp. fits closely to those derived empirically in the current study. When the flagellates were exposed to the flow field of the ciliate Uronema filificum, they both escape responded to the feeding current. From the distance at which the flagellates responded to the ciliate, the critical deformation for escape for both flagellates was estimated to range between 6.9/s and 14.5/s.