Identification:
This elegant flatworm is recognized by its pale or cream-colored background with irregular lines running along the body length. The contrast between the delicate base color and the bold markings gives it a marbled or veined appearance. The margins of the body may be ruffled, helping it glide gracefully over reef surfaces.

Size:
Usually measures around 2 – 3 cm, though individuals may reach up to 4 cm.

Habitat:
Commonly found on coral rubble, reef flats, or under rocks in well-lit areas. This species tends to move slowly and deliberately, often in open view.

Depth Range:
Observed from 3 – 25 meters, most often in shallow reef zones.

Diet:
Feeds on colonial ascidians and other small invertebrates by everting its pharynx to suck in soft tissue.

Reproduction:
Like many polyclad flatworms, it is simultaneously hermaphroditic. Reproduction typically occurs through penis fencing, with both individuals competing to inseminate the other. Fertilized eggs are laid in gelatinous ribbons attached to hard substrates.

Fun Fact:
The species name “contrarius” refers to the asymmetrical or seemingly opposite patterning, which can differ significantly between individuals, making them tricky to identify with certainty!