Identification:
This striking flatworm showcases a silky grey to white base color, dramatically accented by a thick black longitudinal stripe and a bold, ruffled black margin. Its flowing edges and elegant undulations make it unmistakable on the reef. The anterior end bears small pseudotentacles, typical of the Pseudobiceros genus.

Size:
Up to 4 cm in length.

Habitat:
Found crawling on coral rubble, reef flats, and shallow lagoon zones. Often observed during the day, moving gracefully over hard substrates.

Depth Range:
2 – 20 meters

Diet:
Feeds on small sessile invertebrates, using its eversible pharynx to externally digest prey. Likely preys on tunicates or other flatworms.

Reproduction:
A simultaneous hermaphrodite, Pseudobiceros cf. gratus engages in penis fencing, where two individuals duel to inseminate each other. The loser becomes the egg-layer!

Fun Fact:
Its central stripe and black border may serve as visual mimicry or warning coloration, helping deter predators despite lacking toxins.