Class Anthozoa, Order Alcyonacea, Family Xeniidae, Genus Xenia
Common names: pulse coral, Xenia
Natural origin: Indo-Pacific
Sensitivity (Level 1): Though generally very easy to care for, these corals can be somewhat unpredictable. Some colonies show impressive tolerance and forgiveness of varying conditions while others do not. They are also notorious for sudden and unexplainable death and do not ship well.
Feeding: Specific feeding habits are largely unknown. They are thought to absorb nutrients through their soft tissue (possibly aided by the pulsing of the coral).
Lighting (Level 6 to 10): Xenia can adapt to a wide range of lighting conditions, but seem to prefer more intense lighting. As always, be sure to properly acclimate to knew lighting.
Water flow: Moderate to high water flow is important. Higher water flow may increase pulsing activity.
Placement: Though not aggressive corals, like star polyps, they are relentlessly fast growing when healthy. They can become a nuisance in tanks with slower growing stony corals. When injured or dying, they can release toxins. Carbon filtration and prompt removal of injured/dying species can help control any ill-effects of this toxic release.
General: Pulsing activity is something of a mystery (its function and mechanism are currently unknown). Xenia in aquariums sometimes stop pulsing (often without observable cause) but continue to live and grow regardless. Some aquarists have noticed a cessation of pulsing with low pH and/or alkalinity. Polyps will close at night and when stressed. They may take a few days or even weeks to open up in a new environment.