SS1.08 Sensory Ecology, Neurophysiology and Behavior of Zooplankton
Date: Monday, June 10, 2002
Time: 2:30:00 PM
Location: Carson B
 
ClarkeRD, Sarah Lawrence College, Bronxville, USA, rclarke@mail.slc.edu
Buskey, E, J, University of Texas, Port Aransas, USA, buskey@utmsi.utexas.edu
Marsden, K, C, Sarah Lawrence College, Bronxville, USA, kmarsden@mail.slc.edu
 
THE COMPLEX EFFECTS OF NEAR-SUBSTRATE TURBULENCE ON ZOOPLANKTON CAPTURE BY BENTHIC CORAL REEF FISH
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The effects of turbulence on planktivory by fishes is usually considered for open water conditions. Here we explore the effects of turbulence on capture of zooplankton near the benthic boundary layer by small “hemisessile” coral reef fish, two species of chaenopsid blennies. With the aid of high-speed videography, we determined that spinyhead blennies attack their prey rapidly, achieving mean maximum speeds of 227 mm/s, whereas roughhead blennies approach more slowly, achieving mean maximum speeds of 124 mm/s. When feeding on non-evasive prey (brine shrimp nauplii), both species have near 100% success under still water conditions, but spinyheads, with their more rapid attack speeds, have greater capture success than roughheads under strong turbulence. When feeding on evasive prey in still water (calanoid copepods with mean maximim escape speeds of ca. 400 mm/s), roughheads, with their stealthy approaches, have greater success than spinyheads. But under turbulent conditions, both species have greater success, with spinyheads now achieving higher capture rates than roughheads. Turbulence may interfere with the ability of the copepods to detect the hydrodynamic signals associated with the approach of their predators.