Desirable Flabellina

Overview

Coryphellina exoptata, often called the "Desirable Flabellina," is a striking nudibranch known for its vibrant coloration and intricate patterns. This marine gastropod is widely distributed throughout the tropical waters of the Indo-West Pacific, where it is frequently observed in coral reef environments.

Appearance

This species is easily recognized by its translucent, pinkish-violet body, which often reveals internal organs. Its most distinctive features include vivid orange rhinophores covered in over 120 densely packed, elongate papillae. The cerata—the finger-like projections on its back—are arranged in linear rows and display a three-part color pattern: a pinkish-violet base, a deep purple subapical ring, and an opaque, cream-yellow tip. The oral tentacles are similarly colored, typically featuring a purple middle section and a cream-yellow tip, though some regional variations exist where the opaque pigment is absent.

Distribution & habitat

Coryphellina exoptata is found across the tropical Indo-Pacific, ranging from the Indian Ocean—including locations like Mayotte and Réunion—to the western Pacific, including Malaysia, Japan, Australia, New Caledonia, and French Polynesia. It inhabits coral reefs, often favoring vertical walls exposed to currents, which support the growth of the hydroids it relies on for food.

Biology & behavior

As a carnivore, this nudibranch feeds on hydroids such as Halocordyle disticha and Eudendrium species. It possesses a specialized defense mechanism: it consumes the stinging cells of its prey and stores them within its cerata to deter predators. When moving, the animal often displays recurved, tentacle-like foot corners. Its reproductive process involves laying pale, pinkish-orange egg masses directly around the stalks of its hydroid food source.