Galaxea

Galaxea is a genus of colonial stony corals belonging to the family Euphyllidae. These corals are characterized by their star-shaped polyps, which are often numerous and closely packed together, giving the colony a fuzzy or bristly appearance. The tentacles of Galaxea corals are typically extended during the day and night, and they are known for their stinging capability, which they use to capture planktonic food.

The colonies of Galaxea can grow in various forms, including branching, encrusting, or massive structures. The skeletal material, called corallite, is calcium carbonate and forms the hard structure of the reef. These corals are found in a wide range of reef environments, from shallow lagoons to deeper reef slopes, and are common in the Indo-Pacific region. They require moderate water flow and good water quality for optimal health.

Galaxea corals are popular in the aquarium hobby due to their striking appearance and relatively hardy nature. They come in various colors, with green and brown being common. In captivity, they are typically fed with small meaty foods and appreciate stable water parameters. Their stinging tentacles can be a hazard to other corals and invertebrates, so they are often given ample space within an aquarium.