Download Annelida - Effingham County Schools

•Complete questions on Coloring sheet
for tomorrow.
•Complete ‘Scramble Words’ Vocabulary
sheet for Wednesday.
•Quiz on Thursday on the vocabulary for
Annelida
The segmented worms
“annelus” - little ring
I’m metameric
3 classes of Annelida
Class Polychaeta – mostly marine
fanworms, bristle worms, tube worms
Feather duster worms ( Polychaetes)
Filter feeder
Class Oligochaeta - earthworms
Class Hirudinea - leeches
General characteristics
• segmented body
• coelomate
•
Bilateral symmetry
•Longitudinal and circular muscles
• Setae/ bristles used for locomotion
•Soft bodies – hydrostatic skeleton
Respiration:
•In feather duster worms – gills
•Earthworms – moist skin
Specialized structures:
Ex. Earthworm
•Prostomium – used for sensing
and digging through the soil.
•Earthworms have a closed circulatory
system:
•Blood flow in blood vessels – dorsal and
ventral.
• They have 5 pumping ‘hearts’ called
pseudo-hearts or aortic arches. (Color red)
Segments
Segments
Segments
•Digestive system: Mouth, Pharynx, Esophagus,
•Crop (store food), gizzard (ground up food),
intestine (digestion), anus (excretion) Color Green
•Ganglia form ‘brain’. Has a ventral nerve
cord. Color Blue
•Nephridia for excretion
•Clitellum – Secretes mucous ring for
fertilization.
Nephridia – Helps with excretion of
nitrogen containing wastes.
Reproduction: Example - Earthworm
•Sexual reproduction
•Hermaphrodites – Male and Female reproductive
structures.
Eggs produced in ovaries
•Worms exchange sperm:
Sperm produced in testes.
Seminal receptacles receive the sperm
from the other worm during mating.
Seminal vescicles store sperm from other
worm.
•External fertilization in a mucous ring
which becomes a cocoon.
Mucous ring forms at clitellum.
Male
Male
Female
http://www.sciencelearn.org.nz/Science-Stories/Earthworms/Sci-Media/Video/Physical-adaptations-for-life-underground
Mode of nutrition:
Some are filter feeders – Tube worms
Some are carnivores – Nereis
Earthworms feed on decaying vegetation.
Movement:
•Body muscles and a hydrostatic
Skeleton.
•Marine annelids have parapodia
Used for swimming and crawling
•Earthworms have bristle like
Setae to help with movement.