Photographer: Paul Osmond
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An unusual orange spotted version of the polyceridae nudibranch Roboastra gracilis. This species is generally striped rather than spotted, but the hugely disproportioned blue tinged rhinophores and gills are very distinctive.
Like all Roboastra species these are predators, feeding on other nudibranchs. The large oral tentacles are thoughts to help detect and follow mucus trails from its prey.
Image taken on the Monique Bommie dive site on the Great Detached Reef in far North Queensland, Australia. Detached Reef's in this remote area are named as they are near - but not part of - the Great Barrier Reef system.