Brittlestar

Photo: Stefan Pav · © all rights reserved

Ophioderma longicaudum carpets every horizontal ledge surface on the Cape Stavros wall, its five sinuous arms extending to 20 cm and capable of autonomous movement at surprising speed when disturbed. The species plays a significant detritivore role on current-swept walls, processing organic particles that settle on ledges from the water column overhead and recycling nutrients back into the reef system. At night the arms extend vertically into the water column to suspension-feed in a behaviour rarely observed during daytime dives, making a torch dive along the wall a completely different ecological experience from the same site in daylight.