Fuchsia Flatworm

Overview

The Fuchsia Flatworm (Pseudoceros ferrugineus) is a vibrant, free-living marine flatworm known for its striking coloration and distinct body shape. As a benthic, diurnal species, it is frequently observed moving openly across tropical reef environments.

Appearance

This flatworm features an elongated, oval body that can reach lengths of up to 8 cm. Its dorsal surface is typically a rich fuchsia or dark red, densely covered in small white flecks that create a brilliant pink appearance. The body margins are deeply ruffled and often bordered by a solid red band with a thin, bright orange outer edge. At the anterior end, the body folds to form two simple pseudo-tentacles, which are equipped with numerous marginal eyespots.

Distribution & habitat

Widely distributed across the tropical Indo-Pacific, this species is found from the African coast and Madagascar to the Philippines, Indonesia, Australia’s Great Barrier Reef, Micronesia, and Hawaii. It primarily inhabits coral reef slopes and tops, often seeking shelter under ledges, boulders, or rubble at depths between 1 and 25 meters.

Biology & behavior

As a simultaneous hermaphrodite, the Fuchsia Flatworm engages in complex reproductive behaviors, including "phallic duels" where individuals use a specialized stylet to deposit gametes. It is capable of regenerating body parts if injured. The species is a predator that feeds exclusively on colonial ascidians. Its bright colors are thought to be aposematic, serving as a warning to potential predators.