Carpet Flatworm

Overview

The Carpet Flatworm (Thysanozoon brocchii) is a distinctive marine polyclad flatworm known for its textured, papillated appearance. Often found in temperate and tropical rocky environments, this species is recognized by its unique body shape and specialized dorsal protrusions.

Appearance

This flatworm typically reaches up to 8 cm in length and possesses a dorsoventrally flattened, oval-shaped body. Its most striking feature is the dorsal surface, which is covered in short, finger-like papillae that aid in camouflage and oxygen uptake. The body is generally pale with pinkish, frilled margins, though coloration can vary significantly, ranging from pinks and caramels to browns and reddish tones. Some individuals exhibit lighter-colored markings, such as a cross-shaped pattern on the back. At the head, it features a small, pale protruding fold and two tentacles formed by marginal folds, with ocelli (simple eyes) located at their base.

Distribution & habitat

Thysanozoon brocchii has a wide, cosmopolitan distribution, recorded in the Mediterranean Sea, the Atlantic Ocean, the Red Sea, and waters off South Africa, Australia, and India. It is commonly found on rocky substrates, including pebbles, cobbles, and coral rubble, typically ranging from the intertidal zone down to depths of approximately 80 meters.

Biology & behavior

These flatworms are carnivorous, feeding on sponges, bryozoans, tunicates, and small crustaceans. They use chemoreceptors on their tentacles to detect prey and can project their pharynx to feed. As hermaphrodites, they engage in cross-fertilization, depositing egg sheaths on rocks or algae. They are capable of swimming through rhythmic undulations of their body margins and possess a notable ability to regenerate if damaged.