HKBU reef study finds three new coral species in Hong Kong waters

Biologists from Hong Kong Baptist University have discovered three new species of hard coral in Hong Kong waters.  

The three new sun coral species discovered this time were named by the HKBU team as Tubastraea dendroida, Tubastraea chloromura, and Tubastraea violacea, and they all belong to the genus Tubastraea.

The samples were collected when the team surveyed coral-eating nudibranchs at Sung Kong and Waglan Island in the eastern waters of Hong Kong.

The research team noted that there were no reported sightings of the new species prior to their find, and the three new species have now joined the existing seven recognized Tubastraea species around the world.

Meanwhile, the team estimated that both Tubastraea dendroida and Tubastraea chloromura are distributed across Japan and the western Pacific, while the Tubastraea violacea could be exclusive to Hong Kong waters.

Similar to most sun corals, Tubastraea dendroida has a typical bright orange color, but instead of growing in clumps like most of its related species, this new species has a tree-like structure. The HKBU team therefore named it “dendroida” to reflect its tree-shaped body.

As for the Tubastraea violacea, the researchers said it stands out from other related sun coral species as its polyp wall tissues and skeleton are violet in color, and it has been named “violacea” accordingly.

Separately, the Tubastraea chloromura has a delicate olive green skeletal wall and a circle of yellow tentacles surrounding its mouth. As a result, the species has been named “chloromura”, with “chloro” and “murus” meaning “green” and “wall”, respectively, the team added.