Encyclopedia

Anna’s Chromodoris Chromodoris annae   This nudibranch wears a velvety blue mantle like a soft satin cloak, dotted with scattered black specks that give it a playful, starry effect. Its edges are framed with a bold, glowing orange trim, and its feathery gills and antenna-like rhinophores shine in matching orange, adding pops of brightness with every graceful glide. Size: Up to 50 mm Range: Indo-Pacific; from Malaysia and Indonesia to the Philippines and the Marshall Islands Habitat / Depth: Coral reefs and rocky outcrops, found at depths of 15–30 m Diet: Feeds on sponges, particularly those in the Petrosaspongia group....

Diana’s Chromodoris Chromodoris dianae   A tiny reef jewel, this nudibranch looks like it’s wearing a delicate, hand-painted gown. Its translucent white body is streaked with irregular black lines and dotted with tiny black spots, each detail adding to its intricate design. The edges of its mantle glow with a bright orange trim, while its frilly gills and antenna-like rhinophores are tipped in fiery yellow-orange, popping vividly against its pale canvas. Size: Up to 40 mm Range: West Pacific; reported from the Philippines, Indonesia, and Borneo Habitat / Depth: Coral reefs and rocky outcrops, typically found at depths of 1–30...

Ocellated Wart Slug Phyllidiella ocellata   The Ocellated Wart Slug is a small but vividly colored nudibranch, instantly recognizable for its bold orange body accented with black rings and scattered white-tipped tubercles. These “eye-like” spots create a striking pattern that makes the slug appear almost jewel-like against the reef. Its textured, slightly bumpy surface catches the light, while its slow, deliberate movement adds to its mesmerizing presence. This combination of bright orange, deep black, and crisp white makes it one of the most photogenic and easily identifiable nudibranchs in the Indo-Pacific.   Size: Up to 70 mm Range: Indo-West Pacific;...

Swallowtail Headshield Slug Chelidonura hirundinina   The Swallowtail Headshield Slug is a striking black sea slug with two long tail-like extensions. Its body is decorated with vivid turquoise, green, and orange lines that run along the headshield and tails, creating a dazzling contrast against the glossy black. As it glides gracefully over sandy reefs, these bright neon-like stripes shimmer in the light, giving it a hypnotic, almost magical appearance. Its movement is smooth and ribbon-like, making it look as though it’s dancing across the seafloor.   Size: Up to 40 mm Range: Western Indo-Pacific and Caribbean Sea Habitat / Depth:...

Pink Flatworm Prostheceraeus roseus   A delicate ribbon of pink flowing through the reef, this flatworm looks like a silky streamer unfurling over algae and rocks. Its body shifts from soft rose to gentle purple, each edge traced with a faint white line, giving it a dreamlike outline. As it glides with smooth, undulating motions, it almost seems to dance across the shallow waters, its bright coloration warning predators to keep their distance while leaving a trail of hypnotic elegance behind.   Size: Up to 15 mm Range: Tropical Indo-Pacific Habitat / Depth: Rocky reef habitats, found at depths ranging...

Striped Phyllidopsis Phyllidiopsis xishaensis   A tiny marvel of the reef, this nudibranch wears its stripes like a delicate piece of couture. Its pale blue to creamy-white back is streaked with four bold black lines, each ridge rising slightly to create a textured, almost sculpted look. It glides slowly across coral rubble, its lemon-hued rhinophores swaying gently as it explores. This little striped wonder stands out with its precise, elegant patterning and subtle charm.     Size: Up to 40 mm Range: Western Central Pacific; the Philippines and the Marshall Islands Habitat / Depth: Coral reef slopes and rocky outcrops,...