A new species of Phyllodesmium (Aeolidoidea) from Guam (Micronesia) is described. Phyllodesmiumguamensis n.sp. is characterized by having two rows of denticles in the radular teeth, this being different from the previously described species of the genus. The shape of the teeth, however, is identical in all the species of the genus, and unique among aeolids. Furthermore, P. guamensis possesses a double row of cerata in the precardiac cluster and up to 10 post-cardiac ceratal rows. Also, P. guamensis shows a very dense accumulation of zooxanthellae in the ceratal digestive gland, which is ramified inside the cerata. This species feeds on at least three species of the soft coral Sinularia: S. polydactyla, S. maxima and a third, undescribed species. The aeolid matches the colour of its prey and is cryptic on the soft coral surface.

Peer reviewed