Flatworms

Flatworms are flat, unsegmented worms with symmetrical, leaf-shaped bodies. They are tiny creatures, generally growing to a size smaller than a quarter.

What species of flatworms live in the Bay?

Two species of flatworms can be found in the Bay:

• The oyster flatworm, Stylochus ellipticus, is cream-colored with a row of eyespots along the front of the body and short tentacles on the sides.
• The slender flatworm, Euplana gracilis, is yellowish-gray with eyespots in two rows along the head. It lacks short tentacles.

Where do flatworms live?

Flatworms are abundant in the middle to lower Bay among piers, jetties, oyster bars and other hard surfaces in the shallows, as well as in eelgrass meadows.

What do flatworms eat?

Flatworms are major predators of barnacles, bryozoans and oyster spat. Flatworms wait for their prey to open its valves to feed; then the flatworm inserts its mouth into the prey's open valves and feeds on its interior tissues.

How do flatworms reproduce?

The life cycle of flatworms is not well known.

• Oyster flatworms have both male and female reproductive organs, but scientists aren't sure whether each flatworm is able to fertilize its own eggs, or if eggs need to be cross-fertilized by another flatworm.

Other facts about flatworms:

• Flatworms look like "flying carpets" as they glide through the water.
• Have you ever seen a flat, jelly-like blob hiding underneath a rock or shell near the Bay's shoreline? It may have been a flatworm!