Identification:
Bulaceros porcellanus, often called the porcelain flatworm, is instantly recognizable by its smooth, milky white to cream-colored body contrasted with a margin. The body surface appears glossy, giving it a porcelain-like look. Subtle folds and gentle undulations along the edges enhance its elegant appearance. At the anterior end, small ear-like pseudotentacles are visible, characteristic of polyclad flatworms.

Size:
Up to 6–8 cm in length.

Habitat:
Commonly found on coral reefs, reef slopes, and rubble areas, where it crawls openly over hard substrates. It is frequently observed during the day, especially in calm conditions.

Depth Range:
1 – 25 meters

Diet:
A carnivorous flatworm that feeds on small sessile invertebrates. It uses its eversible pharynx to digest prey externally, likely targeting organisms such as ascidians or other soft-bodied invertebrates.

Reproduction:
Like other polyclad flatworms, Bulaceros porcellanus is a simultaneous hermaphrodite. Mating involves the famous “penis fencing” behavior, where individuals attempt to inseminate one another—only the inseminated individual goes on to lay eggs.

Fun Fact:
Despite its delicate, porcelain-like appearance, Bulaceros porcellanus is an active predator. Its striking black-and-white contrast may help deter predators by making it highly visible and unappealing on the reef.