A new species of bioluminescent coral has been found in a deep-sea cave near Minamidaito Island in southern Japan.
Discovered 385 metres beneath the surface, researchers from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) believe the light-emitting coral “represents the first report of bioluminescence observed within a deep-sea cave.”
The newly identified species, described in the journal Royal Society Open Science, has been named Corallizoanthus aureus.
Photograph showing the new species, Corallizoanthus aureus. Hiroki Kise et al. Royal Society Open Science
Lying roughly 225 miles west of Okinawa-jima Island, Minamidaito Island (also spelt Minami Daitō or Minami-Daitō) is known for its dramatic underwater landscape. It’s a topography that has long fascinated researchers, but its steep and complex nature makes studying of the area’s marine biodiversity tricky.
To get around this complication, JAMSTEC scientists decided to deploy a remotely operated vehicle (ROV) – a manoeuvrable underwater machine that is controlled from the surface. This allowed them to explore the challenging marine environment with relative ease.
Whilst negotiating a series of karst caves hundreds of metres beneath the surface, the ROV stumbled upon some corals, which, when poked, blinked bright green. Interestingly, the corals didn’t light up spontaneously – they had to be touched.
The researchers suggest that the bioluminescence of the newly identified species may be acting as a kind of ‘burglar alarm’, where animals looking to prey on the corals activate the light, which attracts second-order predators to the scene, scaring off the initial attackers.
Corallizoanthus aureus colony. Hiroki Kise et al. Royal Society Open Science
Top image: Corallizoanthus aureus colony. Hiroki Kise et al. Royal Society Open Science
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