Anterior and Posterior Suckers are provided, by which the animal attaches itself to the body of the host.
The three Jaws, inside the mouth, causes a painless Y – shaped wound in the skin of the host,
The salivary glands produce Hirudin, which does not allow the blood to coagulate. So, the continuous supply of blood is maintained.
Parapodia and Setae are absent.
Blood is stored in the crop. It gives nourishment to the leech for several months. So there is no elaborate secretion of the digestive juices and enzymes.