Transcript Phylum Chordata

Chapter 24
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2100 are invertebrates
47,000 species are vertebrates
Invertebrate chordates share certain
features with the vertebrates, but not
the backbone (this is at the end of 23
on the notes page)
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Vertebrates are chordates with a
backbone and a brain located inside
a protective chamber of skull bones.
(also at the end of 23)
1.
2.
Notochord – long rod of stiffened
tissue (not cartilage or bone) that
helps support the body.
Nervous system develops from a
nerve cord that runs parallel to the
notochord.
3.
4.
Distinctive slits in the walls of their
pharynx (tube for respiration,
feeding or both.)
A tail forms in embryos and extends
past the anus.
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2000 species
Baglike animals 1
to several cm
long
Filter feeders
Example: “sea
squirts”
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Fish shaped,
translucent animals
Live on seafloors
Have closed
circulatory system.
No complex brain
Filter feeders
Example: Lancelets
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First vertebrates were
jawless or jawed armored
fish. These give rise to the
vertebrates we have today.
Placoderms were the
earliest fish with jaws and
paired fins. With the
jawed fish – biting and
tearing large chunks of
prey became prominent in
the eating process.
Hagfish and Lampreys are
descendents of the first jawless
fish.
 Have a cylindrical body,
cartilaginous skeleton, and no
paired fins.
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Hagfish live in
groups on
sediments.
They eat worms, or
scavenge.
Secrete sticky,
smelly, slimy
mucus
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Lampreys are
specialized
predators that are
almost parasites
Latch on to other
fish and suck out
tissues.
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850 species
Pronounced fins,
skeleton of
cartilage
Scales – small
bony plates at the
body surface
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Skates and rays are mainly bottom
dwellers
Sharks are among the largest living
vertebrates
Chimaera (ratfish) feed mostly on
molluscs
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Most numerous and diverse
vertebrates
Marine predators – torpedo shaped,
flexible body & strong tail
Reef dwellers – box shaped & small
finned
Seahorses are among this class’
members
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An amphibian is a vertebrate with a
body plan somewhere between fish and
reptiles
They must live in an area near water to
keep their skin moist in order to respire
Salamanders live in temperate – tropical
Frogs and toads are most successful
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Eggs are fertilized internally
Reptilian kidneys conserve water
Crocidillians were the first reptile
with a four chambered heart
Reptiles have well –developed lungs
so they do not respire through their
skin.
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Only birds grow feathers – lightweight
structures derived from skin used for
flight, body insulation, or both
9,000 named species of birds
Ostrich is the largest existing bird
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Only vertebrates with hair and mammary glands
Female mammals feed with milk
4500 known species
Range from 1.5 grams to 100 tons
Born with the capacity to learn
Three types: monotremes, marsupials, placentals
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Lay eggs
Feed young milk
Only 3 existing
species: 2 types
of spiny anteater
and the duckbilled platypus
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Young are born at
an early stage
Development is
completed in the
mother’s pouch
Includes koalas,
kangaroos, and
opossums
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Carry young in body until developed
Placenta forms as first organ of
embryonic development
Placenta grows into the uterine wall,
and nutrient/waste exchange occurs
here
Includes humans
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www.nature.com/.../01209/images/ciona_180.jp
g
salinella.bio.uottawa.ca/. ../Images/lancet.gif
pharyngula.org/.../ Bi104/l02/img/DUNK.jpg
www.cyhaus.com/marine/agnathans/hagfish.gif
www.allthesea.com/ img/Spotted-Ratfish.jpg
www.goana.com.au/.../ images/platypus.jpg
www.a-la-carte-australia-tours.com/
images/mar
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http://www.thewildclassroom.com/expeditions/mexico/Pictures/Amp
hibian%20encounter.jpg
http://www.solarexpert.com/fishing/red-salamander-large.jpg
http://www.dkimages.com/discover/previews/873/75016425.JPG
http://www.ashtonbiodiversity.org/images/pet_reptiles_front.jpg
http://www.tpwd.state.tx.us/kids/fun_stuff/images/matching/1birds.
gif
http://kentsimmons.uwinnipeg.ca/16cm05/1116/34-09bLampreyMouth.jpg
http://www.flmnh.ufl.edu/fish/Gallery/Descript/ThornySkate/tskate.J
PG
http://dsc.discovery.com/sharks/shark-types/shortfin-mako-shark.jpg
http://www.savethesea.org/Seahorse.jpg
http://www.student.chula.ac.th/~50373307/picture/FindingNemo.jpg
http://www.extreme-safari.com/images/blue%20marlin%20680.jpg
http://www.moveed.com/data/media/109/birds.jpg
http://kaweahoaks.com/html/oppossum.jpg
http://www.comicvine.com/myvine/cloverfield/all-images/108400509/bruce_chum_anchor/105-1359055
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http://www.disney.co.uk/the-princess-andthe-frog/
http://wallpaperswide.com/tangled_disney_p
ascal-wallpapers.html
http://en.wikipedia.org/wiki/Perry_the_Platy
pus
http://en.wikipedia.org/wiki/Tweety
http://www.disney.co.uk/winnie-thepooh/characters/kanga-and-roo.jsp