ANNELIDA…The EARTHWORM!
Phylum
Class
Family
Genus
Species
- Annelida
- Oligochaeta
- Lumbricidae
- Lumbricus
- terrestris
Part
Function
System
Prostromium
Digs dirt
Digestive
Mouth
Food enters here
Digestive
Brain
Sends/receives nerve
messages
Nervous
Pushes food along
Digestive
Brings food to intestine
Digestive
Pumps blood
Circulatory
Pharynx
Esophagus
Hearts
Seminal receptacle Holds sperm from another Reproductive
worm
Reproductive
Seminal vesicles
Makes sperm
Part
Function
System
Crop
Stores food
Digestive
Gizzard
Grinding food
Digestive
Filters blood (wastes)
Circulatory
Kidney
Ventral Blood Vessel
Absorbs food into blood Digestive
(long)
Circulatory
Brings blood forward
Circulatory
Blood to posterior
Ventral Nerve
Connects brain to body Nervous
Clitellum
Band making slime to
hold eggs
Reproductive
Ovaries
Make eggs
Reproductive
Intestine
Dorsal Blood Vessel
Part
Function
System
Setae
Bristles for hold in
burrow
Movement
Cuticle
Skin-used to
breathe (water)
Respiration
Nephridium
Removes Liquid
Waste
Excretory
Sugar maple forest
before earthworm
invasion
After earthworm invasion
http://www.nrri.umn.edu/worms/forest/index.html
3 ecological groups of earthworms
Endogeic
example:
Aporrectode
a caliginosa
(angle
worms)
Epigeic
example:
Lumbricus
rubellus (leaf
worms)
Anecic :
Lumbricus
terrestris
nightcrawlers
Body Structure: Coelom
7
Digestive System
8
Phylum Annelida
Circulatory System



10
Continuous network of
vessels; 5 muscular aortic
arches
Dorsal blood-Aortic
Arches-Ventral blood
Blood contains
hemoglobin, which
increases oxygen carrying
ability
Phylum Annelida
Excretory & Nervous System
Nervous
system
12
Phylum Annelida
Reproduction
• Hermaphrodites
• Eggs are produced when two earthworms
inseminate each other during mating.
• There are two male openings, and two
pairs of small sacs, the sperm
receptacles. During mating, these receive
sperm from the other partner.
• The eggs, formed in a pair of ovaries, are
released from the oviducts into one of two
Phylum Annelida
13 tiny pores
Reproduction continued
• Fertilization can be internal or external
• Breeding is usually seasonal (spring or
fall)
• Mating occurs usually when the ground is
wet following rain. Earthworms may
emerge and travel over the surface of the
ground before they mate
Reproduction continued….
• The two worms join the lower surfaces of
their anterior ends, with heads pointing in
opposite directions. Mucous is secreted
until each worm is enclosed in a tube of
slime.
• The worms then separate and egg-laying
and fertilization occur later.
• Egg-laying starts when the gland cells of
the clitellum secrete a mucous ring that is
moved forward over the body of the worm
Reproduction continued….
A Worm is Born
• Egg cocoons are
deposited in the soil.
• The fertilized eggs
develop directly into
young worms, which then
escape through the egg
membrane and an
Annelid is born!
Worm Anatomy
External Anatomy:
Internal Anatomy

Please have your Earthworm
colorfun and lab on your
desk







EXTERNAL
Dorsal
Anterior
Mouth
Ventral
Posterior
Clitellum
Setae
INTERNAL
Pharynx
Esophagus
Crop
Gizzard
Intestine
Dorsal BV
Aortic arches
Ventral BV
Seminal vesicles
Ventral nerve cord

Review your colorfun and be
ready to dissect tomorrow! 