annelida by: kiran basava isabelle nievera
TRANSCRIPT
Annelida
By: Kiran BasavaIsabelle Nievera
http://folkworm.ceri.memphis.edu/ew-doc/GIFS/ew.logo.gif
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/earthworms.jpg
Classes
Oligochaetea (earthworms)http://www.freewebs.com/invertebratezoology/Earthworm1.jpg
http://marinediscovery.arizona.edu/alex%20tuttle%20webpage/fireworm.jpg
Polychaeta
http://itsmeela.files.wordpress.com/2007/07/450px-leech_blutegel.jpg
Hirudinea (Leeches)
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.jpg
Body Symmetry
• bilateral symmetry http://www.sheppardsoftware.com/content/animals/images/clipart_earthworm.jpg
http://www.sheppardsoftware.com/content/animals/images/clipart_earthworm.jpg
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/37/73337-004-B0D75E62.jpg
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
Digestive System
• Unsegmented digestive tract• Mouth Pharynx Esophagus Crop Gizzard Intestine
Anus
http://yhsbiology.wikispaces.com/file/view/digest.jpg/49088317/digest.jpg
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
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
Skeletal Type
• None, their bodies are composed a a series of fused segments with muscles
http://www.teachyourselves.co.uk/worm.jpg
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?service=external/ViewImageData&sp=3990
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
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
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
QUESTION #1
1. What type of body cavity do annelids have?
a. Coalomate
b. Pseudocoelomate
c. Acoelomate
d. none
Answer
A. COELOMATE
QUESTION #2
An annelid’s circulatory system includes how many pairs of hearts?
a.6
b.9
c.1
d.5
ANSWER
D. 5
QUESTION #3
Describe the skeletal type of annelids.
a.They have an exoskeleton.
b.The do not have one.
c.They have a cuticle
d.They have a hydrostatic skeleton.
ANSWER
B. They do not
have one
QUESTION #4
How do earthworms exchange gas?
a.Diffusion
b.They do not.
c.They have many tiny blood vessels in their skins, which function as their respiratory organs
ANSWER
C They have many tiny
blood vessels in their skins, which function as their
respiratory organs