Download Vertebrate Beginnings

http://www.youtube.com/watch?
v=kgZRZmEc9j4
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Bilateral symmetry
External segmentation
Coelom
Notochord (vertebral column)
Dorsal nerve cord (spinal cord)
Gill slits at some point in development
Tail at some stage of development
Complete digestive system
 Jawless
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fishes
No scales
Eel like body
Cartilage notochord
No jaw: sucker mouth or biting mouth
Simple circulatory system
Pore like gills
Sense organs: taste, hearing, smell, sight
(poorly developed)
 Hagfishes
 http://www.youtube.com/watch?v=bqk0mnMgwUQ
 Feed
on dead or dying animals
(scavengers)
 Almost completely blind (sense of smell
helps them hunt)
 Hermaphrodites but only one sex
develops
 Create the most slime of any of the fishes

http://www.youtube.com/watch?v=lZq4Dme7wi4
 Lampreys

http://www.youtube.com/watch?v=haUNa9gzymk
 50%
are parasitic (use sucker mouth to
feed off of fish)

http://www.youtube.com/watch?v=EqskoRWMXbA
 External
fertilization (spawning)
 Marine or freshwater
 Sharks, Chimaeras
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and rays
Ventral mouth with rows of teeth
Endoskeleton entirely cartilage
5 to 7 pair of gills
No swim bladder or lungs
Separate sexes with internal fertilization
 Sharks
and rays
 http://www.youtube.com/watch?v=_HaA
U5HP8NQ
 Most are Predators
 Keen sense of smell
 Sense bioelectrical fields when hunting
 Internal fertilization and laying of eggs
Basking Shark is a filter feeder
 Chimaeras

http://www.youtube.com/watch?v=yCsa-YLTQVQ
 Ratfish

http://www.youtube.com/watch?v=yCsa-YLTQVQ
 rabbit
fish
 Spook
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
fish
http://www.youtube.com/watch?v=Zoygy-8PTtU
Ghost fish
 Bony
skeleton
 2 dorsal fins
 Gills and gill arches
 Swim bladder
 True scales
 External fertilization (spawning)

http://www.youtube.com/watch?v=9_TqdcSE5eY
 Ray-finned
fishes
 The fish we are familiar with
 Largest class: 96% of all fish
 Goldfish, carp, trout, bass, salmon,
clownfish,
Lion Fish
The puffer fish uses air to expand
its body to look intimidating to
predtators
Fugu (Japan): Despite precise preparation by specially
qualified chefs, this toxic puffer fish delicacy kills about 300
people per year. The emperor of Japan isn't allowed to eat
fugu lest it be his last meal. For all that work and risk, it still
tastes like fish, but you have to respect the chefs: To prove
their skills, they must cook and eat their own fugu.


http://www.youtube.com/watch?v=JNcfhPG1Svo
http://www.youtube.com/watch?v=MsHCqrrU-Gk
 Lobe-finned
fishes: Lung fish and
coelachanths
 Ancestors
of terrestrial animals
 Have
jaws
 Can survive in oxygen-poor water
because they take air into their lungs and
through their gills

http://www.youtube.com/watch?v=tqWciuuKn3c