White-Tentacle Japanese Aeolis (Sakuraeolis Enosimensis)is a sea slug. One of the most characteristic features of the species are the brilliant opaque white spots and specks scattered over the head and cerata. Grows to or more.
Marine planktonic polychaete worms, genus Tomopteris, are relatively transparent until they shine a deep bioluminescent blue. One species, Tomopteris nisseni, is one of the few creatures on the planet to produce yellow bioluminescence.