Stylochus Visqueux

Overview

Stylochus pilidium is a marine flatworm endemic to the Mediterranean Sea. It is a non-transparent, fleshy worm typically found in shallow coastal waters, often sheltering under stones or within shell-rich environments.

Distribution & habitat

This species is endemic to the Mediterranean. It is commonly encountered in very shallow environments, ranging from just below the surface to depths of approximately 15–20 meters. It frequently inhabits areas under stones, near reefs, and within shellfish farming zones or seagrass beds.

Appearance

This flatworm has a broad, oval, and relatively fleshy body that appears nearly round when at rest. Adults typically measure 20 to 40 mm in length, though individuals up to 70 mm have been observed. The dorsal surface is a light orange-brown, speckled with numerous small, dark spots, while the ventral side is nearly white. A distinct, raised central ridge runs along the body, ending in a whitish patch. It possesses two well-developed, translucent, and pointed nuchal tentacles, which are marked by visible dark eyespots.

Biology & behavior

Stylochus pilidium is a simultaneous hermaphrodite. It is a predatory species that occupies a position low in the food chain. Its development involves a planktonic larval stage known as a Goette's larva, which is characterized by a distinct six-lobed morphology and an apical organ.

Feeding

This flatworm is a hunter that feeds primarily on bivalve mollusks.