The Hammer Coral is a large polyp stony (LPS) coral and often referred to as Euphyllia Hammer Coral or Anchor Coral. Its common names are derived from the appearance of its hammer-, or anchor-shaped tentacles. Its polyps are visible throughout the day and night and hide its skeletal base. It may be green, tan, or brown in color, with lime green or yellow tips on the ends of its tentacles that glow under actinic lighting.
It is moderately difficult to maintain, but with proper water conditions in the aquarium, it will thrive. It will require moderate lighting combined with moderate water movement within the aquarium. At night, its sweeper tentacles can extend up to six inches in the reef aquarium, stinging other species of corals and animals. Allow plenty of room between it and other neighboring corals. For continued good health, it will also require the addition of calcium, strontium, and other trace elements to the water.