Galaxy Coral

Fascinating facts about the Galaxy Coral

• Galaxea fascicularis colonies begin as small low-domed groups but, as they expand, they become irregular, massively hummocky or columnar and can eventually span up to five metres across. They are a common species on reef slopes throughout the Indo-Pacific, especially where wave action is weak. These corals inhabit depths from two to fifteen metres, preferring gently sloping reef faces.
• A few specialised tentacles of Galaxea fascicularis can be extended to thirty centimetres in length and are used to sweep away nearby organisms, defending the coral's space. These sweeper tentacles are usually tipped with white and contrast sharply with the surrounding tentacles. In reef aquaria the coral must be kept at least thirty centimetres away from other sessile invertebrates, because it will sting intruders with these long tentacles.
• Galaxea fascicularis is a common coral but it requires about eight years to reach reproductive maturity, a slow pace that hampers rapid population assessments. Because juveniles remain in the colony for many years, changes in its status are only evident over long time scales. This lengthy development period, combined with its popularity in the aquarium trade, makes it difficult to gauge the impact of harvesting on wild populations.
• Compared with many reef corals, this species shows a notable tolerance to bleaching. Bleaching happens when higher water temperatures kill the symbiotic zooxanthellae that normally provide most of the coral's energy. Even under such thermal stress Galaxea fascicularis often avoids the severe tissue loss seen in more sensitive corals. It also endures being covered by extra sediment better than most reef builders.
• In 2005 Indonesia shipped 17,550 live pieces of this coral, while Fiji and other nations exported smaller quantities. The species is popular among aquarium hobbyists, increasing demand for wild specimens. Because a colony needs about eight years to reach reproductive maturity, such harvest levels are hard to evaluate for their impact on natural populations. This long maturation period means population changes become apparent only over extended time frames.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Galaxy Coral

Galaxy Coral is one of the Indo-Pacific reef's great paradoxes, a stunning, star-spangled colony that is also one of the most lethal competitors in the ocean. Its polyps glow like constellations in dive torchlight, clustered in mounds that can reach three metres across after a century of slow growth. Beneath that beauty lies chemical warfare: at night the colony deploys 30-centimetre sweeper tentacles to dissolve rival corals and expand its territory. Found from the Red Sea to the Pacific across lagoons and reef slopes, it is both a keystone habitat provider and a remorseless spatial competitor, a reef landlord that simultaneously houses hundreds of species and destroys any rival colony that gets too close.

More ocean life to discover

Browse Feravox