Do epibenthic algae induce species-specific settlement of coral larvae?

Effect of epibenthic algae as species-specific coral settlement inducers was examined by laboratory experiments using six Acropora species. When epibenthic algae grew on artificial plates at three depths ( shallow, middle and deep) on a reef slope over a period of two months, there was no effect as species-specific inducers. However, when the growth period was prolonged to five months, the larvae of Acropora digitifera which dominates on the shallow reef slope mainly settled on the plates that were conditioned at the shallow depth, while the larvae of A. muricata which dominates on the middle slope concentrated on the plates that were conditioned at the middle depth. These results indicate that epibenthic algae may act as a cue for the habitat selection of Acropora corals as a settlement inducer. However, the fact that there was no preference for specific plates in other species suggested that epibenthic algae do not act as a sole indicator in selecting a suitable settlement place for Acropora larvae.