Invertebrate Phylum
ANNELIDA(Segmented Worms)
VocabularySetae = tiny bristles projected from
body to help move and dig
Castings = dirt and waste as feces
Gizzard = a muscular region of the digestive tract that breaks down food particles
Crop = structure that stores soil
CharacteristicsA. Body shape = cylindrical with
segments
B. Color = pale red varying from dull pink to brown
C. Size = a few centimeters
D. Lifespan = few weeks to ten years
CharacteristicsE. Body = thick in the middle and
tapers off at each end
F. Senses = touch only
G. Reproduction = hermaphrodites, but cannot reproduce with themselves
LocomotionA. Muscles
a. Circular outer muscles allows the worm to grow longer and thinner
b. Longitudinal inner muscle allows the worm to shrink and widen
B. Setae a. Tiny hairs hook into the ground
allowing worm to push forward
Digestion (Plays an important roll in making soil
more fertile)
A. Burrows and help bring oxygen to plant roots
B Feed on soil and organic matter at the same time
DigestionC. Eliminates dirt and waste as feces
called castings
D. Gizzard grinds dirt and soil in the worm’s digestive tract
E. Food is digested and absorbed by the blood after it goes through intestines
Other AnnelidsA. Leeches (mostly freshwater; can be
found in moist soil)
a. parasites of vertebrates (use jaws to drink blood from host)
b. can be used in surgery to
prevent clotting
Other Annelids
C. Sand worm (found at tide level)
a. eat small, animals
b. have hard pointed jaw