Heidelberg, K. B.. University of Maryland, Department of Biology, kh59@umail.umd.edu
Sebens, K. B.. University of Maryland, Department of Biology, ks95@umail.umd.edu
Purcell, J. E.. University of Maryland Center for Environmental Science, Horn Point Laboratory, purcell@hpl.umces.edu

 
A MODEL OF CORAL HETEROTROPHY BASED ON PREY BEHAVIOR, CORAL MORPHOLOGY AND WATER FLOW
 
Reef corals feed on demersal and holoplanktonic zooplankton. Zooplankton abundance and composition near the substratum on a Jamaican reef was quantified and compared to coral predation rates. A high-magnification video camera and infrared light were used to quantify differences in prey avoidance, escape, and capture. In low flows, prey behavior was very important in determining capture probabilities, and explained observed selective feeding. In higher flows, capture rates were also strongly affected by flow and coral morphology. Tentacle and polyp sizes alone do not appear to determine the size of zooplankton captured. Some corals with small polyps capture more plankton (per unit coral biomass) than do corals with large polyps. Furthermore, large polyps and elongate tentacles capture prey poorly in high flow conditions, due to deformation in flow. We suggest that corals with small polyps and upright, branching structures represent an optimum feeding morphology for higher flow areas. Our data were used to create a preliminary model to describe feeding effectiveness and estimate the potential contribution of zooplankton nitrogen and carbon to coral energy budgets.
 
Day: Thursday, Feb. 4
Time: 10:45 - 11:00am
Location: Hilton of Santa Fe
 
Code: SS22TH1045H