Photographer: Paul Osmond
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This is a beautiful bright purple color form of a Ferrus Polyclad Flatworm (Pseudoceros cf. ferrugineus) on a coral reef near Mabul Island in Sabah, Malaysia.
Polyclad Flatworms are some of the most beautiful of marine species, with the bright colors normally a signal to predators that the species is poisonous or distasteful to eat.