EarthwormsKingdom AnimaliaPhylum Annelida

Class OligochaetaOrder OpisthoporaFamily LumbricidaeGenus Lumbricus

What is an Annelid?

Latin annellus means “little ring”.Annelids are ringed or segmented worms.

Earthworm Facts

Except for the first and last segments, all

body segments have the same sets of organs.

Earthworm Facts

Septa separate one segment

from the other.

Earthworm Facts

Setae are bristles attached to each segment used to help with

movement.

Earthworm Facts - Skin

• They do not have lungs.–They breathe through their moist

skin. If their skin dries out, they will die.

• They do not have eyes– They use light sensitive skin cells

to sense light.

Earthworms obtain food by extending their mucus covered pharynx

Food is then pumped into the esophagus

Food moves to the crop where it can be

stored until…

it is moved into the gizzard where it is ground

into smaller pieces

finally the food is absorbed in the

intestine

Earthworm Facts – Digestive System

Earth worms have a closed circulatory system - blood stays in blood

vessels.

Earthworm Facts – Circulatory System

Aortic arches – Act as hearts; providing pulsation for blood

Earthworm Facts – Circulatory System

Earthworms have 2 major blood vessels that run from head to tail.

1. Dorsal blood vessel - (on the worm’s back) carries blood from the tail to the head

2. Ventral blood vessel - ( on worm’s belly) carries blood from head to tail

Earthworm Facts – Circulatory System

Earthworm Facts - Excretion

Digestive waste passes through

the anus.

Cellular waste is filtered our through the nephridia.

Earthworm Facts – Reproductive System

Earthworms contain both male and female reproductive organs, but they

do not self fertilize.

Seminal Vesicles

Produce Sperm

Seminal Receptacles

Store sperm after mating

Ovaries

Produce Eggs

Earthworm Facts - Clitellum

This is the band of thickened segments towards the head of the worm.

Earthworm Facts - Clitellum

When eggs are ready to be fertilized the clitellum produces a thick mucus

ring. Eggs and sperm are released into this mucus ring, which is

detached and becomes and egg case.

Identifying Structures

Structure ColorPharynx GrayBrain Dark GreenAortic Arches RedEsophagus Light GreenCrop OrangeGizzard Light BrownNephridia YellowIntestine Dark BrownDorsal Blood Vessel RedVentral Blood Vessel RedOvary PinkOviduct PinkSeminal Vesicles Light BlueSeminal Receptacle PurpleTestes Dark BlueCentral Nerve Cord Pick a color you haven’t used

Describe the

function of each

structure.