About Goniobranchus decorus (Pease, 1860)
This species is a chromodorid nudibranch with the scientific name Goniobranchus decorus (Pease, 1860). The body of Goniobranchus decorus is translucent white, marked with opaque white lines, purple spots, and an orange-red sub-surface margin. A white line typically outlines the central region of the back, and this line can extend into white patches that run toward the midline. The midline itself is usually marked with white patches or a broad white stripe with diffuse edges. A small number of purple spots lie within these white markings, and these spots usually form a line down the center of the back, with each spot always surrounded by a white halo. The tips of the rhinophores and the outer portion of the gills are white. This species was originally described from Hawaii. It has often been confused with Goniobranchus setoensis, so many existing records of the species are actually misidentifications. Its confirmed distribution spans the western Pacific Ocean, from Hawaii to the Marshall Islands and New Caledonia. Goniobranchus decorus and Goniobranchus setoensis occur together (are sympatric) in the Marshall Islands. Goniobranchus decorus feeds on sponges in the family Aplysillidae, including the species Chelonaplysilla violacea.
