HR: 15:25h
AN: OS53B-08    [Abstracts]
TI: Planktivorous Fish Recognize Temporal Motion Patterns of Suspended Particles
AU: * Strickler, J R
EM: jrs@uwm.edu
AF: University of Wisconsin - Milwaukee, WATER Institute 600 E Greenfield Ave, Milwaukee, WI 53204 United States
AU: Tsonis, A
EM: aatsonis@uwm.edu
AF: University of Wisconsin - Milwaukee, Dept of Mathematical Sciences, Milwaukee, WI 53201 United States
AB: Small planktivorous fish feed by selective captures of individual zooplankters. We realize that: 1) the predator, as well as the prey is suspended in the water column, which does not provide either with stable reference points; 2) the ambient flow field acts differently on the larger predators than on the much smaller prey; and 3) within the water column there are many suspended particles of lower nutritional value than the zooplankters represent. We investigated in the laboratory whether or not fish can distinguish between small targets moving with different swimming patterns, e.g. particles entrained passively in the ambient water flow versus entrained but actively swimming particles. We created in an aquarium computer-animated stimuli with motion patterns ranging from random to actual swimming motions of live animals. The results show that planktivorous fish can recognize temporal patterns in a visually homogeneous environment. Therefore, blue-water fish must process visual information similar to terrestrial animals processing auditory information.
DE: 4815 Ecosystems, structure and dynamics
DE: 4817 Food chains
DE: 4842 Modeling
DE: 4855 Plankton
DE: 4524 Fine structure and microstructure
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting