The charitable organization Coral Sea Foundation has observed Bluelined surgeonfish, Acanthurus lineatus, actively suppressing coral growth at one of its monitoring sites, Lizard Island, on the Great Barrier Reef. Also known as the Lined Surgeon, or Clown Tang, A.lineatus is widespread in the Indo-West Pacific where it is often observed in shallow surge zones. Like many algae grazing surgeons, it is aggressive and territorial, staking out a patch of algae and defending it from rival grazers, but that’s not all it protects its patch from. It prevents the growth of plating corals which would otherwise shade out its algal pastures and future feeding grounds, as the Coral Sea Foundation explains:
“Unlike a damselfish which enhances the growth of juvenile corals so that it can later use them as a framework for its algal farm, the Bluelined Surgeonfish does NOT want corals growing in its territory, especially not plate corals which create shade and therefore compromise the food resource.”
“At our monitoring sites at Jiigurru (Lizard Island) where we have been following the reef recovery, we have noticed that the Bluelined Surgeonfish are actively nipping at the edges of the plate corals in their territories, suppressing their growth and significantly modifying their shape into mushroom-like pedestals. There are quite distinct differences in coral cover between reef crests with and without Bluelined Surgeonfish, and this is a topic that warrants further detailed research.”
Blueline Surgeonfish are widely available and inexpensive in the hobby. Attaining a length of up to 14” they require long tanks with high flow and just like in the wild can become aggressive and territorial when adult. These large, lyre-tailed beauties are generally reef safe although they have been observed nipping at aquarium corals occasionally. This may be why!
Coral Sea Foundation’s aim is to raise awareness of the ecological and social value of the Coral Sea and Eastern Coral Triangle and to be proactive in its sustainable management. More at www.coralseafoundation.net
