In the late 1970s, Hypselodoris peasei was a very common species on subtidal reefs around Oahu. They lived along short walls and in ledges and small caves eating a yellow sponge. Often 20 or 30 or more specimens could be found on a single yellow sponge colony, and their combined grazing could completely wipe out the sponge. This species seems to be active only during the day. At night, the nudibranchs would crawl under the sponge or into crevices to hide.
A few bubbles from the photographer's breathing have collected on the ceiling of a small cave where the nudibranchs below were feeding on yellow sponge.
Here about 16 nudibranchs munch away the last of a sponge colony.
These nudibranchs have eaten part of a sponge colony, exposing a bare patch on the reef.
Created 20 April 2009