Staphylaea staphylaea can be immediately recognized by its blue color, finely pustulose surface, and teeth that cover most of the base. The only similar species is S. limacina, which is much more coarsely pustulose and whose teeth do not extend out over the entire base. Specimens are most often found under rocks on the tops of rubbly lagoon pinnacles. Occasionally they are also found along interisland lagoon reefs such as that near Ebwaj Island (Shell Island) or even right off Kwajalein’s Emon Beach at depths ranging from 1-10m. The black mantle covering the shell often blends in well with their typical food source, a jet black encrusting sponge on the undersurfaces of some rocks. The mantle color does vary, however. Some of the black ones have lots of white spots or white branching papillae. In some specimens, the mantle is more reddish than black. This species ranges through the Indo-Pacific with the exception of Hawaii. The subspecies found in the Marshall Islands is Staphylaea staphylaea staphylaea.
Updated 23 February 2020