Anatomy from the medicinal bdella (hirudo medicinalis)

The medicinal bdella (lat. hirudo medicinalis) is related as worm to the earthworm. The bdella became smaller an oval cross section at the two body ends. At the two ends is in each case a suction cup. The suction cup in the back, serves the bdella only for holding. The suction cup contains the mouth opening in front.

In the mouth the jaw those is appropriate for 3 approx. 80 lime denticles has. The three radially arranged jaw have approx. 80 fine lime teeth. At each suction cup is a nerve ring. The body is flattened and consists of 33 segments. The back is dark green and has at both sides ever 3 brown longitudinal strips. The bdella does not possess a brain.

For surviving the bdella needs a damp environment, since it would drain otherwise. In the time of sheding its skin, the bdella is unpowered because of this work.

In the water the bdella induces itself like a dolphin, ashore uses the bdella its suction cups to progressive movement. The bdella supervises the water movements in the water, to which it recognizes potential victims.