algal toxins alter copepod feeding behavior藻毒素改变桡脚类动物的摄食行为.pdfVIP

Algal Toxins Alter Copepod Feeding Behavior 1 1 1 2 3 Jiarong Hong , Siddharth Talapatra , Joseph Katz *, Patricia A. Tester , Rebecca J. Waggett , Allen R. Place4 1 Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland, United States of America, 2 National Ocean Service, National Oceanic and Atmospheric Administration, Beaufort, North Carolina, United States of America, 3 Department of Biology, The University of Tampa, Tampa, Florida, United States of America, 4 Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, Maryland, United States of America Abstract Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major) to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod’s feeding appendages–a ‘‘sampling beating’’ that has short durations (,100 ms) and involves little fluid entrainment and a longer duration ‘‘grazing beating’’ that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. ton