Phyllidiella pustulosa (Cuvier, 1804)

Phyllidiella pustulosa is probably the most often observed nudibranchs in the Marshalls, both because it is common and because it tends to sit out in the open on hard substrates during the day. Like other Phyllidiids, this species has chemical defenses to help prevent it from being eaten. We have seen them at Enewetak, Kwajalein, and Bikini Atolls on a variety of lagoon and seaward reefs from a depth of about 4 down to at least 60 meters.

This is one of several similar species that probably constitute an example of Mullerian mimicry.

The smaller animal in the photo below resembles a form of what we are calling Phyllidiella zeylanica.

Since both of these were found apparently eating the yellow sponge below, I'm guessing that the smaller one at the bottom of the photo, which measures 3 to 4mm in length, is a juvenile Phyllidiella pustulosa.

An anal papilla appears to be protruding from the lower part of the left specimen below.

Created 25 December 2006
Updated 27 June 2008