Healthy coral reefs are architecturally complex environments sporting a diversity of structures that include corals, overhangs, grooves, tunnels and spurs. This structural complexity is one of the elements that makes coral reefs so visually appealing, but hidden within the reef complex there might be certain shapes that are particularly important for the survival of reef fish.
It is well-known that intricate branching corals are the preferred habitat for many species of small reef fishes, but there is only anecdotal evidence for the structures preferred by larger coral reef fish. We therefore set out to investigate whether or not larger reef fish show a preference for certain shapes of corals, and studied three of the most common growth forms: table corals, branching corals and dome-shaped corals.
We used underwater video cameras to record the behaviour of large reef fish interacting with these corals at a number of sites around Lizard Island in the northern Great Barrier Reef. Careful analysis of the video footage showed a very clear pattern for the majority of the large reef fishes – they vastly preferred table corals over branching or dome shapes.
There were consistently greater numbers of large reef fish gathering around table corals. These individuals tended to be significantly larger than the fish associating with the other shaped corals studied...
