Annelida: Leech Predation and Digestion

Many leeches have a proboscis used for swallowing the prey or for sucking its fluids; others have jaws for biting. Many parasitic leeches are able to parasitize a wide variety of hosts. Most of the marine and some of the freshwater leeches are fish parasites. The medicinal leech, Hirudo medicinalis, is one of a group of aquatic bloodsucking leeches with jaws. Another group of jawed bloodsuckers is terrestrial; these leeches live in damp tropical vegetation and drop onto their mammalian prey. Most parasitic leeches attach to the host only while feeding; a single meal may be 5 or 10 times the weight of the leech and provide it with food for several months. The digestive tract of bloodsuckers produces an anticoagulant, hirudin, which keeps the engorged blood from clotting. A few leeches attach permanently to the host, leaving only to reproduce. Predatory leeches are active at night and hide by day.

Sections in this article:

• Introduction
• Leech Reproduction
• Leech Predation and Digestion
• Leech Anatomy
• Class Hirudinea
• Oligochaete Reproduction
• Oligochaete Circulation and Respiration
• Oligochaete Digestion
• Oligochaete Anatomy
• Class Oligochaeta
• Archiannelida and Myzostomaria
• Polychaete Reproduction
• Polychaete Anatomy
• Sedentary Polychaetes
• Errant Polychaetes
• Class Polychaeta
• Reproduction
• The Nervous System
• Respiration
• Circulation
• Digestion
• The Body Wall
• Segmented Bodies
• Bibliography

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.

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