annelidae these guys try to worm their way into all ways of life
Post on 21-Dec-2015
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Annelidae
These guys try to worm their way into all ways of life
Typical dissection approach
I. General Characteristics• A. Bilateral symmetry• B. Cephalization• C. Coelom• D. Complete digestive tract• E. Segmentation• F. Nephridia• G. Circulatory system• H. Hydrostatic skeleton
II. Organ systems
• A. Digestive System
• 1. muscular pharynx
• 2. esophagus• 3. crop• 4. gizzard• 5. intestine
B. Nervous system
• 1. ganglia• 2. ventral nerve cord
C. Circulatory system
• 1. closed circulatory system
• 2. dorsal blood vessel
• 3. five pairs of pseudohearts
• 4. ventral blood vessel
• 5. capillary network
D. Reproductive system• 1. hermaphroditic• 2. male parts• 3. swapping of
sperm• 4. clitellum• 5. female parts
impossible to find for average
The Great Exchange
Fertilized eggs released in a cocoon
E. Excretory system-nepridium
• 1. almost every segment has a nepridium
nephridium
III. Classes of annelids
• A. Oligochaets• 1. setae not
huge• 2. useful for
anchorage during locomotion
• 3. sequence of muscle contraction
B. Polychaets
• 1. parapodia• 2. much more
elaborate• 3. locomotion• 4. moving fluid
through tubes• 5. excavation in
marine worms• 6. respiratory
surfaces
Polychaet-feather duster worm
Christmas Tree Worm
C. Hirunidea-leeches
• One of man’s best friends
Wonderful story• http://www.youtube.com/watch?v=ak6MX-QFRVc&
NR=1
http://www.youtube.com/watch?v=SxZbzZ5RE40&feature=related
Cross section
• 1. coelom• 2. dorsal blood
vessel• 3. ventral nerve
cord• 4. muscle layers• 5. typhlosole• 6. nephridia• 7. setae