Encyclopedia

Psychedelic Batwing SlugSagaminopteron Psychedelicum Barely two centimeters long, this tiny sea slug makes an extraordinary amount of visual noise. Its pale body is scattered with irregular orange patches outlined in black, while the edges of its broad side flaps glow with soft orange and white. A warm orange-red head and translucent, speckled gill complete the pattern, giving the little slug an almost candy-colored appearance. When disturbed, those side flaps can beat against the water and send it briefly swimming away from the reef. Size: Up to around 20 mm, with some records reaching approximately 30 mm Range: Indo-West Pacific; including...

Scrambled-Egg NudibranchPhyllidia Varicosa The nickname makes sense at first glance, with bright yellow tubercles scattered across a blue-gray body like little pieces of egg. Although, looking at those rounded yellow patches, it arguably looks more like a collection of fried eggs than scrambled ones. The uneven shapes and raised centers give each marking its own character, while dark lines wind between them across the back. It is an oddly convincing breakfast comparison for an animal that could not look less like anything you would find on a plate. Size: Up to around 100 mm Range: Widespread Indo-Pacific, from the Red...

Kunie’s ChromodorisGoniobranchus Kuniei Creamy yellow spreads across the broad mantle of this nudibranch, crowded with purple-ringed spots that seem to ripple outward from the center. Three deep violet bands circle the edge, giving the body a bold, layered border, while yellow-tipped rhinophores and pale gills rise from the middle of all that color. As it crawls, the wide mantle lifts and falls in a slow rhythm, making the whole animal seem to breathe with its own flowing fringe. Size: Up to around 60 mm Range: Indo-West Pacific; from the eastern Indian Ocean through Indonesia, the Philippines, New Caledonia, Fiji, Australia...

Pyjama NudibranchChromodoris Quadricolor The name suits this nudibranch almost perfectly. Pale blue and white bands run lengthwise across its back, broken by bold dark stripes that give it the unmistakable look of a tiny pair of striped pyjamas. A bright yellow-orange border wraps around the mantle, with matching orange rhinophores and gills adding a lively finishing touch. It is an unusually playful pattern for a creature carrying such a serious warning, since its vivid colors advertise the chemical defenses it gains from the sponges it feeds on. Size: Up to around 50 mm Range: Red Sea, western Indian Ocean, and...