1. 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

3. LOBSTER MOLTING http://www.evtv1.com/player.aspx?itemnum=12531
SPINIEY LOBSTER MOLTING
CRAYFISH MOLTING

4. The body has 2 segments - a cephalothorax covered by the carapace and the abdomen and is bilaterally symmetrical.
Meroplanktonic larvae don’t compete with adults for food;
metamorphosis provides a gradual change to adult life.
An open circulatory system contains a blue pigment called
hemocyanin to transport oxygen from the gills to the body.

5. Unlike the red pigment hemoglobin, their blood carries copper instead of iron.
It makes an excellent medium for long-term laboratory tests because it will not support bacterial growth.

6. 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

7. Crayfish Dissection
Link