Annelida
From Microcosm Aquarium Explorer
Fireworm with segments clearly visible. Scott W. Michael
[edit] The Segmented Worms
Number of Living Species: 12,000.
Common Characteristics: elongate, wormlike animals with segmented bodies; anterior end bears jaws, eyes, tentacles, and antennae; body segments equipped with stiff bristles known as chaetae (used in locomotion and venomous in some polychaetes).
Noteworthy Behaviors: some are raptorial predators with complex jaws, capturing other invertebrates and even fishes; others exist on algae, while many are omnivores, consuming algae, other invertebrates, and detritus.
Class Polychaeta (Polychaete Worms): 8,000 species