Turbellaria are a group of generally small (<1 - 60cm) and free-swimming members of the flatworm phylum Platyhelminthes. Their locomotion depends on cilia. Most turbellaria are carnivorous, and actively scavenge for food. Most species are marine and freshwater dwellers, but some have evolved to dwell on humid land, as well.

Planarian (Dugesia)

The planarian Dugesia is a common representative of Class Turbellaria. This common flatworm can be found in freshwater habitats. Their digestion tract consists of a central tubular pharynx. Each branch consists of ceca, which delivers the nutrients to the body. This worm has a sac digestive plan, that is, it does not have a separate opening for waste excretion. (Gilbertson, 1999).

Planarians have ocelli (eye spots) that detect the amount of light in the nearby environment, and auricles (ear-like flaps) that detect the amount of water current.

References

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• Gilbertson, Lance; Zoology Lab Manuel; McGraw Hill Companies, New York; ISBN 0-07-237716-X (fourth edition, 1999)

Flatworms

Strudelwürmer | Planaire | Virnjaci | Turbellaria | Wirki | Turbellaria | Ploskule | Virvelmaskar | 涡虫纲