what is sactorial mouth where it …

Leeches are ectoparasites and they mostly live on the blood of vertebrate animals, like - humans, cattle, etc. They have a sanguivorous i.e. blood-sucking feeding habit. The blood-sucking habit of Leeches is supported by a special adaptation in their mouth.Their mouth is a narrow triradiate aperture that sits at the center of the pre-oral chamber of the oral sucker. The oral sucker (or anterior sucker) is a tiny hollow muscular organ present at the anterior end of the animal body. The pre-oral chamber is actually a cup-like depression at the ventral surface of the oral sucker. One ray of the mouth is in medio-dorsal position, while the other two are placed ventro-laterally. This specially modified mouth of the Leeches is called suctorial mouth. When a feeding leech firmly adheres to the host body, its suctorial mouth moves like a saw and makes a triradiate (i.e. Y-shaped) painless incision in the victim's skin. Then the oozing blood of the host is sucked by the Leech.