Transcript Slide 1
By John Cashman and Jason Holthaus What is it? • • • • • 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 • • • • Lives in marine habitat Over 10,000 different species Ex. Bristle Worms Polychaeta is Latin for “many bristles” • • • • • 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 • • • • • 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 • • • • • • 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>.