Scientific Name: Mexichromis pusilla

Adult Size: Up to 15 mm.
Depth Range: Typically observed between 5 – 35 m.
Biotope / Habitat: Commonly found on coral rubble, encrusting sponges, or dead coral surfaces in reef environments. It often inhabits areas with rich sponge growth, as this provides both food and shelter.
Diet: Feeds mainly on specific species of encrusting sponges. Like other members of the Chromodorididae family, it absorbs defensive chemicals from its prey, making it distasteful to predators.
Reproduction: A simultaneous hermaphrodite. After mating, it deposits small, coiled egg ribbons on hard surfaces, often near its food source. Larvae are planktonic before settling and developing into the adult form.
Fun Fact: Although tiny, Mexichromis pusilla is a favorite among nudibranch enthusiasts because of its vibrant color and elegance, making it a rewarding find for macro photographers.

Mexichromis pusilla is a small but striking dorid nudibranch. It is easily recognized by its smooth, narrow body adorned with a vivid orange to pinkish mantle. The mantle is typically bordered by a thin white or pale yellow margin. The gills and rhinophores are a matching shade of orange, blending harmoniously with the body color. Its delicate and clean coloration makes it stand out despite its small size. The gills form a tight circle near the rear of the body, and the rhinophores are smooth or slightly wrinkled.