1. In the upcoming slides you will see pictures of several arthropods
In the upcoming slides you will see pictures of several arthropods. For each picture: Describe what you see. Be detailed! (Ex: How many legs, what color, what shape, ext)

2. Barnacle

3. Lobster

4. Beetle

5. Spider

6. Scorpion

7. Horseshoe Crab

8. Blue Crab

9. Krill

10. Ant

11. What do all of these organisms have in common?
Write this in your “Characteristics of Arthropods” Before Box.

12. 2. What characteristics do you think of when you hear “Crustacean”

13. 3. Describe a unique characteristic of barnacles.

14. 4. What do you know about “Decapods”

15. 5. Why is krill important to the marine food chain?

16. Crustaceans

17. Arthropod Overview Phylum Arthropoda = arthropods (“jointed feet”)
Characteristics
Jointed appendages
Tough exoskeleton made of chitin
Varies from flexible to hard
Acts as a protective cover
Place of attachment for muscles

18. Crustacean Features
Crustaceans: marine animals that have hard outer coverings
Other characteristics include:
Bilateral symmetry
2 main segments
Cephalothorax (includes head and chest) covered by the carapace
Abdomen (includes a tail if present)

19. Crustacean Features

20. Look at Those Legs!
Crustaceans like crabs, lobsters, shrimps etc. have 5 pairs of legs (they are known as decapods)
1st pair = claws (used for food-getting)
2nd – 5th pairs = walking legs
Some crustaceans have special swimmerets (located under the abdomen) that help them glide along the sea bottom

21. Growth Under the Exoskeleton
Crustaceans shed their exoskeleton once or more during the year by molting.
New exoskeleton is secreted inside the old one which splits open
Animal pushes its body out through the gap between the thorax and abdomen
New shell is very soft and the animal is vulnerable to predators

22. The Lobster
Lobsters are able to release their arms from their sockets to get away from predators or other aggressive lobsters (they will regenerate the limb)

23. Fiddler Crab
Named for its large claw which looks like the arm position of a person playing the fiddle; if a large claw is lost, a small one grows in its place and the other claw grows into a large claw

24. Mole Crab
Adapted to live in the surf zone because of its streamlined body that helps it burrow into the sand

25. Hermit Crab
Born without an exoskeleton on its abdomen, so it lives inside empty snail shells.

26. Structures and Activities of Crabs
Structure of the Crab
Segemented into cephalothorax and abdomen (which is very small)
Both parts are covered by the carapace
Female crabs have a U-shaped abdomen while male crabs have a V-shaped abdomen