Planaria

Planaria sp., or cross-eyed worm, is a common freshwater flatworm. It moves by cilia on the ventral dermis, allowing it to glide along on a film of mucus. Some move by undulations of the whole body by the contractions of muscles built into the body wall. Planaria are a member of the class Turbellaria and the phylum of flatworms, Platyhelminthes. They exibit an extraordinary ability to regenerate lost body parts. It size range from 3 to 12mm and your body has two eye-spots (also known ocilli), used to move away from light sources. The more frequently used in laboratory is the brownish Dugesia tigrina. Other common varieties is the blackish Planaria maculata and Planaria dorotocephalia.