Goniobranchus coi

Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Nudibranchia
Family: Chromodorididae
Genus: Goniobranchus
Species: Goniobranchus coi

Goniobranchus coi is a chromodorid nudibranch and one of the more entertaining slugs to watch on a Philippine dive.

It has a cream to yellow body, a dark brown wavy band just inside the mantle margin, and orange-brown spots on the back. The mantle edge is broad and frilly.

It is famous for mantle flapping. As it crawls along the bottom it waves its mantle skirt up and down, which is why Nudibranchs of the Philippines calls it the Marilyn Monroe nudi. This may increase water flow over the gills, and it is also thought to confuse predators from above. Like other chromodorids it feeds on sponges.

The flapping is best captured on video, so switch modes if you find one on the move.

It appears on page 115 of Nudibranchs of the Philippines.

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