Choanoflagellate Swarming and Mating (IMAGE) University of California - Berkeley Caption A mating swarm of the marine choanoflagellate S. rosetta, triggered by the bacterium V. fischeri. Tubulin is labeled gold, highlighting the cell body and flagellum, while the protein actin is labeled blue, showing off the organism's distinctive collar. Credit Arielle Woznica and Nicole King, UC Berkeley. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.