Annelida: Class Oligochaeta

This class includes about 3,500 species of earthworms and freshwater worms. The members of the class range in length from about 1⁄32 in. to 10 ft (0.5 mm–3 m), but most are comparable to the polychaetes in size. Oligochaetes occur in a variety of habitats throughout the world. Most are burrowers in the soil, but the class also includes worms that inhabit wells, marshes, and swamps. Other species live under rocks on the seashore, in the leaves of tropical trees and vines, on the surface of glaciers, or on the gills of freshwater crayfish.

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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