study these notes for the test

1. Phylum: AnnelidaPhylum: Annelida
Class: OligochaetaClass: Oligochaeta
By Mr. “The Man” ChapmanBy Mr. “The Man” Chapman

2. OligochaetaOligochaeta
 EarthwormsEarthworms
 OligosOligos
– fewfew
 chaitechaite
– hairhair
 Few hairsFew hairs

3. OligochaetaOligochaeta
 About 3,000About 3,000
speciesspecies
 Mostly terrestrialMostly terrestrial
and freshwater.and freshwater.
 Earthworms haveEarthworms have
poorly developedpoorly developed
heads and setaeheads and setae

4. OligochaetaOligochaeta
 Oligochaetes have setae, but a lotOligochaetes have setae, but a lot
fewer than polychaetes.fewer than polychaetes.

5. EarthwormsEarthworms
 Earthworms liveEarthworms live
under the soilunder the soil
surface and feedsurface and feed
on decomposingon decomposing
organic material.organic material.
 As they burrow,As they burrow,
they swallow soilthey swallow soil
and they digest theand they digest the
organic material inorganic material in
soil.soil.

7. OligochaetesOligochaetes
 At night, they move to the surface toAt night, they move to the surface to
pass the soil as a waste.pass the soil as a waste.

8. Earthworms are ecologically important. Their burrows
allow air to make its way into the soil where it can
support plants’ root cells as well as other fossorial
animals.
In a year,
earthworms will
stir the top 12
inches of soil in a
typical field.

10. EarthwormsEarthworms
 ClitellumClitellum –– is non-segmented section
of the body (looks like a band aid)
near the head in earthworms and
leeches, that secretes a sac with
eggs.

11. Cross Section of OligochaetaCross Section of Oligochaeta

12. The largest
earthworm
species grow to
3 feet in length
and it stretches
to 9 feet when
crawling.