Earthworms Phylum Annelida Class Oligochaeta

Where do earthworms live? They live in burrows in the dirt They live in burrows in the dirt They tunnel in the soil– this helps the soil become loose They tunnel in the soil– this helps the soil become loose It also cycles nutrients & lets air in It also cycles nutrients & lets air in

How do they move? They crawl using muscle contractions that shorten and lengthen the body They crawl using muscle contractions that shorten and lengthen the body They can grip the soil using setea or little hairs on the ventral surface They can grip the soil using setea or little hairs on the ventral surface Lots of mucus Lots of mucus

External Features Sensitive skin – can sense light, touch & chemicals Sensitive skin – can sense light, touch & chemicals Mouth, anus, clitellum, many segments Mouth, anus, clitellum, many segments

What do earthworms eat? Soil and the organic material in it Soil and the organic material in it The food enters the mouth and pharynx where saliva gets it moist The food enters the mouth and pharynx where saliva gets it moist The crop stores it and the gizzard grinds it up The crop stores it and the gizzard grinds it up The intestines absorb nutrients, the anus expels waste (castings) The intestines absorb nutrients, the anus expels waste (castings)

Respiration, Circulation, Nervous System Diffusion of gases through skin Diffusion of gases through skin 5 pairs of hearts (10), 2 main blood vessels 5 pairs of hearts (10), 2 main blood vessels Simple nervous system with cerebral ganglion & ventral nerve cord Simple nervous system with cerebral ganglion & ventral nerve cord

Reproduction Hermaphroditic Hermaphroditic 2 worms come together ventrally and exchange sperm 2 worms come together ventrally and exchange sperm Later the each worm excretes a cocoon surrounding the worm, as it slides forward, the sperm is released and the eggs fertilized the worm slips out of the cocoon Later the each worm excretes a cocoon surrounding the worm, as it slides forward, the sperm is released and the eggs fertilized the worm slips out of the cocoon