Planarian
... an undulating motion. The movie to the right shows a Dugesia tigrina from Emigration Creek moving under a dissecting microscope. REPRODUCTION Dugesia tigrina reproduces both sexually and asexually. Under the appropriate conditions of temperature and food, asexual individuals pinch in around mid-length of the worm's body. The pinching continues until the two halves are complete. Each half will then form a whole worm. This asexual reproduction occurs only above 10degrees C with the frequency of division increasing to a maximum at 25 to 28 degrees C. Sex organs may develop during the winter and early spring in some strains of D. tigrina. Planarians are hermaphroditic in that organs for both sexes develop on each worm. Egg capsules, or cocoons that are oval in shape and about 5 mm long, are deposited in May and...