Hypselodoris decorata

Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Nudibranchia
Family: Chromodorididae
Genus: Hypselodoris
Species: Hypselodoris decorata

Hypselodoris decorata is a chromodorid nudibranch, part of the colourful family that includes many of the reef's best-known slugs.

It has purple spots, white flecks and banded rhinophores. It looks almost identical to Hypselodoris maculosa, and for a long time the two were easy to mix up. The way to tell them apart is the rhinophores: H. decorata has three dark rings or bands on each, while H. maculosa has only two.

Like other Hypselodoris it feeds on sponges and is usually seen crawling in the open during the day.

To be sure of your ID, get a sharp close-up of the rhinophores and count the bands. That one detail is what separates it from its look-alike.

It appears on page 151 of Nudibranchs of the Philippines.

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