Scientists from the Hebrew University of Jerusalem have discovered why some corals use energy to pulsate. These fascinating corals are the only organisms in the ocean besides jellyfish that pulsate. Scientists found out that these corals pulsate in order to move food closed to them. After watching several coral colonies with a camera night and day they found that the coral cease to pulsate and take a half-hour break every single day in the afternoon hours. Analysis of the direction of water flow showed that corals sweeps water up and away from their tissues into the ambient water. Corals need carbon-dioxide during daytime and oxygen during nighttime, as well as nutrients during day and night. for this reason this type of coral pulsates.