Phyllidiella pustulosa is probably the most often observed nudibranch 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 1 down to at least 60 meters. It is also one of the most visible nudibranchs at every tropical Indo-Pacific area we have visited, including Hawaii, Pohnpei, Nauru, Chuuk, Fiji, and the Solomons.
This is one of several similar species that probably constitute an example of Mullerian mimicry.
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. These two animals are similar to some web photos of Phyllidiopsis hageni.
The specimen below is presumably a young specimen. It was found at Kwajalein on 22 February 2010.
The one below appeared to be feeding on the brown sponge.
A couple of shots of an individual with its egg mass laid flat against the substrate.
Created 25 December 2006
Updated 8 April 2016
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