1. Phylum Arthropoda

3. What animals are arthropods?
Trilobites (Extinct!)
Part of Paleozoic
marine ecosystems
Bodies divided into
3 long vertical lobes
with many legs
Most were
bottom feeders.

4. Crustaceans:

5. Found in oceans, freshwater streams and
some on land.
Diverse group – range from huge king
crab to microscopic copepods and oyster-like
barnacles

7. Chelicerates

8. Share a set of specialized dagger like mouth
parts used for tearing their food.

9. Insects:

10. 80% of all known species
Most are terrestrial
Have 6 legs

11. Myriapods – Centipedes and Millipedes
Long bodies
Many pairs of legs

12. ‘Shongololo’ – giant millipede
found in Southern Africa
From Zulu and Xhosa – means to ‘roll up’

13. Characteristics:
Exoskeleton made of chitin
Jointed appendages – can have 6, 8, 10 or
even 100’s. Used for walking, swimming,
sensing, manupilating food, chewing

14. Charactertics (continue..)
Segmentation

15. Arthropods must shed exoskeleton = molting Process has steps:
New layer of cuticle secreted underneath
exoskeleton.
Enzymes are secreted to digest and weaken
old cuticle.
New exoskeleton is filled with fluid, takes
time to harden.