A new species of coral, which contains no symbiotic algae, has been discovered.
The coral was found living on the ceilings of caves up to 35m deep on coral reefs in the Indo-Pacific. It has been given the scientific name, Leptoseris troglodyta, which means "one who dwells in holes".
It differs from its closest relatives in that it contains no symbiotic algae (zooxanthellae), possibly explaining the white appearance of the coral, similar to specimens that have become 'bleached' after losing this algae.
It has a very small polyp size, compared to other corals in the genus and it grows very slowly, possibly because of the lack of zooxanthellae — but that comes in handy, because space on the cave ceilings is limited.
The size, shape and habitat of Leptoseris troglodyta are unique compared to other Leptoseris species. Other species in the genus have symbiotic algae, although many of them are still able to live on deep, poorly illuminated reefs or rocky substrates. From an evolutionary perspective, scientists say that this new species may have lost the capacity to live in symbiosis with zooxanthellae and it may have obtained a smaller corallum size (dwarfism).
Leptoseris troglodyta was found in what is known as the Coral Triangle — a region of the Indian and Pacific Oceans well known among scientists for the biodiversity of its marine life. It is the first known shallow-water agariciid without zooxanthellae.
It's hoped that this discovery can help shed light on the relationship between reef corals and symbiotic algae.
You can read more in the open access journal ZooKeys: Hoeksema BW (2012) Forever in the dark: the cave-dwelling azooxanthellate reef coral Leptoseris troglodyta sp. n. (Scleractinia, Agariciidae). ZooKeys 228: 21. doi: 10.3897/zookeys.228.3798
Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.