Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Phylum Annelida (Earthworms, Sandworms, Leeches) By: Veronica Weigandt Key Characteristics • • • • • • Bilaterally symmetrical Closed circulatory system Has a nervous system Segmentation True Coelom No true respiratory organs Anatomy • • • • • • • Segmented Intestine Anus Nerve Cord Coelom Septa Dorsal/Ventral blood vessel • Nephridia • Clitellum Anatomy (Cont.) • • • • • Mouth Pharynx Esophagus Crop Gizzard Digestive • 1 way digestion • Food goes into mouth • Pharynx helps food into mouth • Food is stored in crop • Gizzard breaks down food • Rest goes through intestines Respiration • Simple diffusion • Oxygen is consumed by body cells • Carbon dioxide diffuses through the body surface Internal Transport • Closed system of blood vessels • Blood pumps through body • Circulation Excretion • Nephridium • Fluid passes through nephridium into bladder-like sac • Sac opens through a pore in the skin & waste is discharged Response • Has a brain • Responds to: – Odors – Changes in moisture – Changes in temperature – Changes in light Movement • Various muscle groups • Parapodia • Setae sinks into the ground • Longitudinal muscles contract Reproduction • Reproduction is sexual • Join head to tail; exchanging sperm • Forms mocous sheath • Eggs get released into the sheath • Worm backs out of sheath • Sperm gets released into the sheath & fertilization occurs • Cocoon develops Examples Sandworms Leeche s Earthworms Facts • Over 22,000 species • They live just about anywhere on earth • Most are found in wet environments • Can grow up to as long as 3 meters • Can range in their color, patterning, and other features Literature Cited • http://www.bu.edu/gk12/eric/Annelida.pdf • http://www.esu.edu/~milewski/intro_biol_two/lab__12_anne l_arthro/Annelida.html • http://www.infusion.allconet.org/webquest/annelida.html • http://library.thinkquest.org/28751/review/animals/5.html# • http://www.biology-questions-andanswers.com/annelids.html • http://www.encyclopedia.com/topic/Annelida.aspx