Aquatic Sciences Meeting, Albuquerque 2001

PC03 Undergraduate Education

Date: Tuesday, February 13, 2001

Location: Southwest Hall

Slajer, A, , Shannon Point Marine Center REU of Western Washington University, Anacortes, USA, aim@scientist.com

CHEMICAL INHIBITION OF GRAZING BY AMPHIDINIUM LONGUM

Emiliania huxleyi, a unicellular phytoplankton, is suspected of using dimethylsulfoniopropionate (DMSP) as a defense against grazing. The heterotrophic dinoflagellate Amphidinium longum has been found to selectively eat E. huxleyi strains with low DMSP lyase activity. Some strains of E. huxleyi may leak DMSP, causing a concentration gradient around the cells and deterring Amphidinium. Five chemical analogs of DMSP, in various concentrations, were tested to determine their affects on Amphidinium as they grazed on E. huxleyi 374 and Pyrenomonas salina, which are preferred foods. The effects of 1.0mM concentrations of dimehtylsulfide and Na acrylate on Amphidinium as they grazed on P. salina were also investigated. Finally, E. huxleyi 373 cells (not a preferred food) were treated to try to make them palatable to Amphidinium. I found that both DMSP and glycine betaine inhibited feeding by Amphidinium. None of the treatments could make Amphidinium eat E. huxleyi 373.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks