Caramel Nudibranch

Overview

The Caramel Nudibranch (Glossodoris rufomarginata) is a striking marine gastropod widely distributed across the tropical Indo-Pacific. Often favored by underwater photographers, this diurnal species is frequently observed crawling along rocky reefs and coral environments.

Appearance

This nudibranch features an elongated, whitish body densely covered in tiny red to orange-brown speckles, which can give the animal a brownish appearance from a distance. Its mantle is well-developed with a distinctively wavy edge, characterized by a broad white submarginal band and a vibrant orange or reddish outer border. The retractable rhinophores and gills are typically orange-brown with white highlights, and the foot also displays a white margin.

Distribution & habitat

Glossodoris rufomarginata is found throughout the tropical Indo-Pacific, ranging from the Red Sea and East Africa to Hawaii and Polynesia. It inhabits a variety of environments, including rocky bottoms and coral reefs, and is particularly common on shaded cliffs or in protected areas, though it can also be found in more exposed locations.

Biology & behavior

As a diurnal species, it is active during the day and is generally solitary. Like other nudibranchs, it is a simultaneous hermaphrodite, and it reproduces by laying white, coiled egg ribbons on or near its food source. To defend against predators, it can secrete toxic substances.

Feeding

This species feeds primarily on sponges, including those from the family Thorectidae. It is often found directly on or in close proximity to its host sponge, which may appear cream-colored where the nudibranch has grazed on the surface.