Hosted by the School of Biological Sciences

Once a year after the annual spawning event, the larvae of reef-building corals swim and probe the environment in search for suitable adult habitat. They use a multitude of sensory cues. For example, they must determine whether there is enough light available for their photosynthetic symbionts, then make the decision to attach to a substrate and metamorphose. The larvae are able to do this without any recognisable eye structure or a centralised nervous system. Anatomical examination with electron microscopy and immunohistochemistry can be used to search for their morphologically-inconspicuous photoreceptor cells and try to reconstruct a connectome map of their larval nerve net. Meanwhile, behavioural assays revealed that larvae respond strongly to changes in light by stopping swimming and changing shape. Thier simple light-guided behaviours work effectively to prevent the eyeless coral larva from swimming into and settling in unsuitably dark crevices or deep water.