Annelida

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Annelida

• By Kiran Basava
• Isabelle Nievera

http//folkworm.ceri.memphis.edu/ew-doc/GIFS/ew.lo
go.gif
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Annelida

• Means little rings which resembles the annelids
  body, which is a series of fused rings.
• Live in the sea, freshwater habitats, and damp
  soil.

http//www.botswanagallery.org/thesis/A/img2/earth
worms.jpg
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Classes
http//www.freewebs.com/invertebratezoology/Earthw
orm1.jpg
http//marinediscovery.arizona.edu/alex20tuttle2
0webpage/fireworm.jpg
Oligochaetea (earthworms)
Polychaeta
http//itsmeela.files.wordpress.com/2007/07/450px-
leech_blutegel.jpg
Hirudinea (Leeches)
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Body Cavity

• Present
• Have a true coelom, a body cavity completely
  lined by tissue derived from mesoderm

http//www.glogster.com/media/2/3/92/77/3927715.jp
g
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Body Symmetry

• bilateral symmetry

• http//www.sheppardsoftware.com/content/animals/im
  ages/clipart_earthworm.jpg

http//www.sheppardsoftware.com/content/animals/im
ages/clipart_earthworm.jpg
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Nervous System

• A brain-like pair of cerebral ganglia above and
  in front of the pharynx
• A ring of nerves around the pharynx that connects
  to a subpharyngeal ganglion, from which a fused
  pair of nerve cords runs posteriorly.

http//media-2.web.britannica.com/eb-media/37/7333
7-004-B0D75E62.jpg
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Circulatory System

• Have a closed circulatory system
• 5 pairs of hearts
• Blood vessels circle esophagus and pump blood

http//infusion.allconet.org/webquest/img010.jpg
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Digestive System

• Unsegmented digestive tract
• Mouth? Pharynx? Esophagus? Crop? Gizzard?
  Intestine? Anus

http//yhsbiology.wikispaces.com/file/view/digest.
jpg/49088317/digest.jpg
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Excetory System

• Annelida have excretory organs called nephridia,
  directly remove waste from the bloodstream
• In earthworms (class Oligochaeta), waste is used
  to fertilize the soil

http//image.tutorvista.com/content/excretion-and-
osmoregulation/septal-nephridia-illustration.jpeg
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Locomotion/Musculature

• Each segment of an earthworm is surrounded by a
  longitudinal muscle that coordinates with a
  surrounding circular muscle to allow an earthworm
  to move
• Polychaetes have parapodia (almost feet) to
  move, and polychaetes and leeches can swim

http//mfaucher.com/files/Uganda03/675dpi/ug14_25.
jpg
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Skeletal Type

• None, their bodies are composed a a series of
  fused segments with muscles

http//www.teachyourselves.co.uk/worm.jpg
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Sensory structure/features

• Have tactile organs (touch), taste buds,
  photoreceptor cells, and some have eyes with
  lenses
• Palps and antennae are located on the head
  (tactile)
• Also have lateral organs- epidermal sensory cells
  that are responsive to light or touch

http//tolweb.org/onlinecontributors/app?servicee
xternal/ViewImageDatasp3990
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Reproduction

• Hermaphrodites
• Cross fertilize by aligning to exchange sperm,
  which is stored while an organ called the
  clitellum makes a cocoon that receives the eggs
  and sperm from the worm, and remains in the soil
  while embryos develop.

http//www.offthemarkcartoons.com/cartoons/2005-11
-11.gif
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Gas Exchange

• Earthworms have many tiny blood vessels in their
  skins, which function as their respiratory organs
• The blood has hemoglobin that carries oxegen.
• In leeches, most gas exchange occurs through the
  body wall

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Unique Characteristics

• Easily recognized due to segmented bodies
• Most segments have the same internal structures
  repeated throughout the worm
• Leeches used to be used for blood letting, and
  today are used to drain blood that accumulates in
  tissues after injuries or surgeries

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QUESTION 1

• What type of body cavity do annelids have?
• Coalomate
• Pseudocoelomate
• Acoelomate
• none

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Answer

• A. COELOMATE

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QUESTION 2

• An annelids circulatory system includes how many
  pairs of hearts?
• 6
• 9
• 1
• 5

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ANSWER

• D. 5

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QUESTION 3

• Describe the skeletal type of annelids.
• They have an exoskeleton.
• The do not have one.
• They have a cuticle
• They have a hydrostatic skeleton.

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ANSWER

• B. They do not have one

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QUESTION 4

• How do earthworms exchange gas?
• Diffusion
• They do not.
• They have many tiny blood vessels in their skins,
  which function as their respiratory organs

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ANSWER

• C They have many tiny blood vessels in their
  skins, which function as their respiratory organs