Feather-duster worms.

Feather-Duster Worms

GROUPS OF ANNELIDS

There are more than 15,000 species of annelids.

HIRUDINEA: Leeches

Most leeches live in fresh water. They lack appendages. Leeches may be carnivores or blood-sucking external parasites. Example: medicinal leech (Hirudo medicinalis)

An earthworm.

Giant Earthworm

POLYCHAETA: Polychaetes

Polychaetes live in salt water; many move with paddle-like appendages called parapodia tipped with bristle-like setae. Examples: sandworms, bloodworms, fanworms, feather-duster worms

A bearded fireworm with white, bristle-like structure on the sides.

The white, bristle-like structures on the sides of this bearded fireworm are setae.

OLIGOCHAETA: Oligochaetes

Oligochaetes live in soil or fresh water. They lack appendages. Some use setae for movement but have fewer than polychaetes. Examples: Tubifex, earthworms


End ofPage DOL 41

Table of Contents

Miller & Levine Biology UNIT 1 The Nature of Life UNIT 2 Ecology UNIT 3 Cells UNIT 4 Genetics UNIT 5 Evolution UNIT 6 From Microorganisms to Plants UNIT 7 Animals UNIT 8 The Human Body A Visual Guide to The Diversity of Life Appendices Glossary Index Credits