Sell, A. Woods Hole Oceanographic Institution, asell@whoi.edu

 
PREDATOR AVOIDANCE AND PHYSIOLOGICAL CHANGE? TANK EXPERIMENTS ON VERTICAL MIGRATION BEHAVIOR IN THE COPEPOD ACARTIA TONSA
 
To investigate regulation of migratory behavior in Acartia tonsa and possible coupling of behavioral with physiological changes, I tested the following hypotheses: 1) Diel vertical migration in A. tonsa is regulated by the diurnal cycle in light intensity and is independent of the presence of predators. 2) Migratory behavior of A. tonsa changes in the presence of predators. 3) In response to the presence of predators, respiratory enzyme activities in the electron transport system (ETS) change in A. tonsa. In a newly designed experimental setup consisting of four acrylic tanks (20* 20* 120 cm), I used a motorized video system to take profiles of the vertical distribution of A. tonsa. Experiments lasted 72 hours each, with a 14:10h L: D cycle and profiles taken at 4 h or 6 h intervals (infrared illumination during dark periods). For predation trials, I inserted mesh cages at the water surface to hold the predators and allow for passage of potential chemical cues. Results showed an internal rhythm of migration in Acartia tonsa that existed without exposure to predators. Video recordings from the predation trials are currently being analyzed and will be related to activity of the electron transport system in A. tonsa.
 
Day: Thursday, Feb. 4
Time: 02:30 - 02:45pm
Location: Hilton of Santa Fe
 
Code: SS16TH0230H