EarthwormsMarine worms Leeches
Annelida means “little-rings” Segmented worms Found in freshwater, saltwater, and moist soil
Body cavity with organs Bilateral 2 body openings Setae: bristle-like structures on outside of body used to hold on to soil and to move
>100 segments Move using setae and 2 sets of muscles in the body wall Eats soil – food moves to crop for storage – gizzard for grinding – intestines for absorption – exits thru the anus
Closed-circulatory system Gases exchanged through skin and mucus layer Small brain called ganglia Hermaphrodites – but can’t fertilize themselves
No setae Eat blood from other animals Prevent blood coagulation
Aerate soil Medical uses Food for other animals