Mar 2
Photo of Ctenella chagius in coral reef habitat

Ctenella coral (Ctenella chagius)

Species: Ctenella coral (Ctenella chagius)

Status: Endangered (EN)

Interesting Fact: Ctenella chagius is the only coral species in the Meandrinidae family to occur in the Indian Ocean rather than in the Caribbean Sea.

Ctenella chagius forms hemispherical colonies which are green, cream or light brown and have wavy ridges across their surface. As in other corals, the colonies of this species are composed of numerous small, anemone-like animals known as polyps. The polyps secrete a hard skeleton which over many generations helps to form a coral reef. Ctenella chagius is found only in the Chagos Archipelago in the western Indian Ocean, where it lives on reef slopes and in lagoons at depths of up to 45 metres.

Like other corals, Ctenella chagius is threatened by climate change, which is likely to cause increased sea temperatures and more frequent, damaging storms. Rising carbon dioxide levels are also making the ocean more acidic, making it harder for corals to produce their hard skeleton, while other threats to corals include human development, overfishing, pollution and invasive species. Fortunately, much of the range of Ctenella chagius is now protected in the world’s largest marine reserve, the Chagos Archipelago Marine Protected Area. This area now needs to be effectively enforced, and further research is needed into Ctenella chagius and the threats it faces.

Find out more about conservation in the Chagos Archipelago at the Chagos Conservation Trust.

Find out more about coral conservation at Reef Check and The Coral Reef Alliance.

See images of Ctenella chagius on ARKive.

Corals feature in ARKive’s new online game – play Team Wild here!

Liz Shaw, ARKive Text Author