The question is whether or not a calanoid copepod can take advantage if it suddenly encounters a high concentration of food items.
The animal, Eucalanus pileatus, was tethered to a dog hair. Algae were in the water at natural densities. A micropipette filled with india ink delivered the tracer of the flow (india ink). The flow is generated by the movements of the mouth parts. The inner mouth parts remain motionless until an alga is close-by and detected. Then a fast movement is executed to capture the alga. Thus, the flow is disturbed for a short moment. The question then is: how did the animal “know” that an alga was close-by?
EEucalanus pileatus from the Coral Sea demonstrates a large palette of food handling behaviors. Here the animal has to deal with many algae within a very small time interval. The zooxanthellae are leaky algae – normally they exchange chemicals with their host. The animal senses the food chemically and during the one second feeding bout tries to capture as many as possible
avid Sutton (AIMS at that time) helped us with the food particles. He extracted the zooxanthellae from several soft corals minutes before we used them as food. The movies were made at 500 frames per second; here you see one clip at 30 frames per second. The other persons involved in obtaining this observations were Eleanor Hing-Fay, and Paul Dixon