A coral that was previously thought to be extinct has been rediscovered in the Chagos Archipelago. The Chagos Brain Coral, Ctenella chagius, is endemic to the Chagos islands in the Indian Ocean. It belongs to a monotypic genus within Meandrinidae, a stony coral family that is characterized by having meandering valleys containing evenly spaced corallites. It was collected and described some 100 years ago but mass bleaching events in 2015 and 2016 were thought to have wiped it out. A century ago it was one of the 25 most abundant corals in the region. In 2020 Dr. Bryan Wilson of the Department of Zoology, at the University of Oxford traveled to the Chagos Archipelago to try and find it, fearing it was lost forever. “I had been waiting so long to have access to these reefs again, to see whether this species had continued to hold on by the very tips of its polyps.”
In a video named On the Edge of Existence: Rediscovering a Lost Coral, Dr. Wilson boards a research vessel headed for the Chagos Archipelago, 500km south of the Maldives, 1500km to the east of The Seychelles, and 3000km to the west of Indonesia. The voyage was part of a collaborative research program including 93 scientists from 24 institutions. Due to Coronavirus, the entire trip had to be aborted, but in 2021 Bryan returned and found it. Because it only comes from a certain region and low remaining wild colony numbers make successful reproduction more difficult, it’s one of the rarest corals in the world. It also faces the continued threat of bleaching events. Ex situ coral spawning guru Dr. Jamie Craggs is featured in the video and assisted reproduction efforts are being made to help bolster the numbers of wild populations. Take a minute to watch the video and lose yourself in the azure blue waters of the Chagos Archipelago.
