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PHYLUM ARTHROPODA
Numerically the largest phyla and
literally means jointed foot.
Class: Crustacea - crab, shrimp,
barnacle and lobster (Florida
specie has no claws)
1. Jointed appendages have a variety of specialized functions
2. The body is covered by an exoskeleton made of chitin
Advantage: good protection, muscles attach to it for strength
Disadvantage: heavy and does not grow & animal must molt
(shed) exoskeleton
- becomes very vulnerable to predators & only time to mate
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LOBSTER MOLTING http://www.evtv1.com/player.aspx?itemnum=12531
SPINIEY LOBSTER MOLTING http://www.youtube.com/watch?v=TsddAy5ujKE
CRAYFISH MOLTING http://www.youtube.com/watch?v=BjFI7gxwtJE
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3. The body has 2 segments - a cephalothorax covered by the
carapace and the abdomen and is bilaterally symmetrical.
4. Meroplanktonic larvae don’t compete with adults for food;
metamorphosis provides a gradual change to adult life.
5. An open circulatory system contains a blue pigment called
hemocyanin to transport oxygen from the gills to the body.
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Unlike the red pigment hemoglobin, their blood
carries copper instead of iron.
http://www.youtube.com/watch?v=e8KlAmtIu1E
It makes an excellent
medium for long-term
laboratory tests because
it will not support
bacterial growth.
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6. They have a ventral nerve cord with a well-developed brain
and compound eyes. Well-developed nervous system
7. Gills – under carapace
8. Bottom dwelling crustaceans have appendages specialized
for walking
9. Chitinous teeth in stomach for grinding
10. Separate sexes, males transfer sperm directly to female,
female broods eggs then releases
11. Planktonic larvae - meroplanktonic
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