Ginn, J. A.. Yale University, Jennifer.Ginn@Yale.edu
Miller, T. A.. University of Maryland Center for Environmental Sciences, miller@cbl.umces.edu
Sandford, L. P.. University of Maryland Center for Environmental Sciences,

 
EFFECTS OF SMALL-SCALE TURBULENCE ON INGESTION RATES AND SWIM SPEEDS OF MNEMIOPSIS LEIDYII
 
The MacKenzie et al. (1994) model suggests that small-scale turbulence causes an increase in encounter rate and a decrease in pursuit success, resulting in a dome-shaped response of overall feeding success in larval fish. The assumption that predator swim speeds remain constant and independent of turbulent velocity was tested. Mnemiopsis leidyii was chosen for the study because of its sensory predation, which allowed the assumption that pursuit time for the predator was negligible. Feeding experiments were run in an oscillating chamber with adjustable turbulent velocity, and ingestion rates were determined in initial functional response experiments. Motion analysis was performed on the ctenophores under different turbulent velocities. Overall feeding success of M. leidyii showed a dome-shaped response, indicating that there may be a minimal pursuit time for the predator, or that it is protecting itself in higher turbulence at the cost of feeding. The mean swim speed of M. leidyii increased as a function of turbulent velocity, suggesting that the model's assumption that swim speeds remain constant cannot be made. The results indicate that the model is a helpful tool, but requires specific knowledge of the feeding behavior of the predator and a modification to account for changes in predator swim speed as a function of turbulence.
 
Day: Monday, Feb. 1
Time: 04:00 - 04:15pm
Location: Sweeney Center
 
Code: SS01MO0400S