Transcript Slide 1

By John Cashman and Jason Holthaus
What is it?
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Latin word anellis which means ring
Annelids are ringed worms
Differentiated by their segments
Length: <1 inch and upwards of 11 feet
Uses chaetae (small bristles) to move
What are Chaetae?
• Voice Thread!:)
• A voice thread link that will help you to
understand more about what the chaetae
is and its function
• Oceans
• Fresh Water
• Land
• Earthworms are commonly sold as
bait
• The same goes with leeches
• Earthworms are also do great
things for the soil in gardens
• Leeches saliva may someday also
be used to prevent blood clots in
humans
Food Source
• Heterotrophic creatures (require organic
substances)
• Earthworms ingest soil and extract
nutrients from it
• Leeches are predators that usually
swallow their prey but sometimes just suck
the blood
• Bristle worms move their bristles and trap
particles to ingest
How They’re Unique
• All have segmented bodies
• Bodies are sealed with a wall or septa
• Each segment contains separate
body parts
• They have evolved to be more
adaptable to their environment
Polychaete
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Lives in marine habitat
Over 10,000 different species
Ex. Bristle Worms
Polychaeta is Latin for “many
bristles”
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Lives on land
3,500 species
Also live in swamps and marshes
Oligochaeta means "few-bristled”
Ex. Earthworms
Hiruindea
• Around 500 species
• Live on land,
saltwater, and
freshwater
• Some suck blood, but
many don't
• Have little to no
chaetae
• Ex. Leech
• Annelids use their strong muscles to
support their shape
• They are an invertebrate meaning
they have no bones
• Their ring-like muscles help them to
support their shape
• Oxygen is diffused through body
surface
• Then it is used by the capillaries
• These are very close to the surface
and make it easier to use the oxygen
• Carbon Dioxide is then diffused back
out through the skin
• Some Annelids use asexual reproduction
– This means they can produce offspring by breaking
off part of their body
• Some are also hermaphrodites
– This means they have characteristics of both sexes
• Many though have either male or female and
require a partner to reproduce
• They develop segment by segment until
adulthood
• Very primitive brain by the mouth
• They have nerve cords traveling the length
of their bodies
• Sensory Organs
– Eyes
– Taste buds
– Tactical Tentacles
– Statocysts
• Annelids have a closed circulatory
system
• Ring vessels function as small
hearts
• Blood moves to the head through a
contractile vessel
• The two main vessels are the dorsal
and ventral blood vessels
Excretory System
• Central unit is the Nephridia
• There are different types of Nephridia for
different types of Annelids
• The Protonephridia are joined to a duct
that flushes out of the subject
• The Metanephridia contain cilia and open
to the outside of the subject
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One long digestive tract
Food is stored in the crop
Ground up by the gizzard
They have unsegmented guts.
Also have separate pharynx and
stomach
Examples
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Earthworms
Bristle Worms
Leeches
Lug Worms
Bamboo Worms
And thousands more
Basic Annelid Diagram
Works Cited
Flourence, Wayne K. "Annelida (Segmented Worms, Including Earthworms,
Leeches and Polychaetes)." Biodiversity Explorer. 24 May 2007. 02 Apr.
2008 <http://www.biodiversityexplorer.org/mm/annelids/>.
Miller, Kenneth R., and Joseph Levine. Biology the Living Science. Needham:
Prentice Hall, 1998. 447-452.
Myer, Phil. "Phylum Annelida." Animal Diversity Web. 2001. University of
Michigan Museum of Zoology. 02 Apr. 2008 <
http://animaldiversity.ummz.umich.edu. Annelida.html>.
Parker, Steve. Nematodes, Leeches & Other Worms. Minneapolis: Compass
Point Books, 2006. 18-21.
Ramel, Gordon. "The Phylum Annelida." Earthlife. 7 Jan. 2008. Earthlife Web. 1
Apr. 2008 <http://www.earthlife.net/inverts/annelida.html>.
Rouse, Greg W. "Annelida." Tree of Life. 07 Aug. 2002. Australian Research
Council.1 Apr. 2008 <http://www.tolweb.org/Annelida>.
Russel, Bruce J. "Branches on the Tree of Life: Annelids." Bio Media
Associates. 2000. 02 Apr. 2008
<http://ebiomedia.com/prod/BOanelids.html>.