Three Lined Aeolid - Orienthella Trilineata
This nudibranch feeds on hydroids, and prefers those growing on algae. Like other nudibranchs, the undischarged nematocysts (stinging cells) of the hydroid, are stored in the feathery cerata on its back. Studies of a similar species show that the nematocysts may only last around 4 days before they need to be replaced.
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