Parasitology Lec 5: Phylum Annelida-segmented worms

this is an older classification system, but still used: Class Polychaeta-describe

Many chaetae (“setae”)- huge class, mostly marine, clam worms, scale worms, and fire worms. -tube worms and burrowing worms

class Oligochaeta:

few chaetae (“setae”) *know! Mostly freshwater and earthworms

Class Hirudinida:

leeches

the newer system: clade (class) Errantia- means

“freely moving”

Errantia-describe

Contains many of the marine polycheates, usually predators or scavengers, head well developed, parapodia are large and used for crawling (display tufts with many setae and size increases gas exchange), dioecious

clam worms:

(Nereis): four pairs of sensory tentacles on the head, swim with a lateral undulatory movement

scale worms:

flattened bodies with broad scales

fire worms:

Hollow, brittle, setae contain a poisonous secretion