07 February 2014
Vol 343, Issue 6171

About The Cover

Cover image expansion

COVER Water swirls in a vortex above two millimeter-sized coral polyps (pink and purple) in "Invisible Coral Flows," which won first place in the photography category of the 2013 Science/NSF International Science & Engineering Visualization Challenge. The vortex, driven by the polyps' wafting cilia, helps the coral draw in nutrients and sweep away waste products. The winning entries are featured in a special section starting on page 599 and at Photo: Vicente I. Fernandez, Orr H. Shapiro, Melissa S. Garren, Assaf Vardi, Roman Stocker/Massachusetts Institute of Technology