Protocooperation among small polyps allows the coral Astroides calycularis to prey on large jellyfish

Predation on the large, venomous jellyfish Pelagia noctiluca by the stony coral Astroides calycularis is illustrated. The coral occurs in the western Mediterranean, while the jellyfish is cosmopolitan in temperate and warm seas. The coral lacks symbiotic zooxanthellae and has small polyps with tiny mouths. It forms cup- shaped colonies on vertical cliffs and caves, in shallow waters. It was thought that its diet was made of small- sized zooplankton and particulate matter. Unexpect-edly, small polyps belonging to the same or different colonies collaborate, allowing the coral to take advantage of large but ephemeral food resources.