1. Most widespread and abundant phylum of animals
ARTHROPODS
Most widespread and abundant phylum of animals
3 out of 4 animals are arthropods!

2. Classification
Two major subphylums that marine arthropods are found in
Subphylum CRUSTACEA
Suphlyum CHELICERATA

3. Appendages specialized
CHARACTERISTICS
Exoskeleton made of chitin
Segmented body
Appendages specialized
Sensory, feeding, movement
Can regenerate appendages
Gills to obtain oxygen from sea water

4. Well developed organ systems Open CS Well developed NS Complete DT
GENERAL CHARACTERISTICS cont…
Well developed organ systems
Open CS
Well developed NS
Complete DT
Reproduction-separate sexes and sperm is usually directly transferred to the female

5. Crustaceans Largest marine group
Biramous appendages- legs branch off into 2 parts

7. Crustaceans molt-shed their shell & grow a new one as they grow.

8. The swimming legs of crustaceans are called swimmerets.

9. Crustacean Habitats
Mostly a marine group
Insects of the sea
Important members of benthic
communities
dark nooks (under rocks and crevices)

10. Detritivores (scavengers) Parasites Carnivorous
CRUSTACEAN FEEDING
Detritivores (scavengers)
Parasites
Carnivorous

11. Maxilopeds- special appendages (arms)for cutting and manipulating food
Mandible- Special mouthparts for chewing food

12. Serial homology of appendages as seen in a stomatopod
Serial homology of appendages as seen in a stomatopod. From left to right appendages are: antennule, antenna, mandible, first and second maxillae, first through fifth maxillipeds, 3 walking legs, 5 pleopods with pinkish gills, and uropod.

13. -may be the most common animal
Copepods
-may be the most common animal
-important as zooplankton
and food source for larger consumers

14. Parasitic copepod in mako gills

15. Many copepods are parasites of fish.

16. usually attached to surfaces (very particular about where they attach)
Barnacles
filter feeders
usually attached to surfaces (very particular about where they attach)

17. Most diverse and widespread small crustacean
Amphipods
Tiny and shrimp-like
Most diverse and widespread small crustacean

18. Isopods flat from top to bottom successful on land too

20. Krill
shrimp-like
important in polar waters as food source for whales, penguins, seals

21. 1st pair of legs for defense and getting food
Decapods
1st pair of legs for defense and getting food
Well developed carapace (outer shell)
Can feel pain

22. - 4 pairs of jointed walking legs compound eyes on stalks
Lobsters
large front claws
- 4 pairs of jointed walking legs
compound eyes on stalks

24. Lobsters may live to be 100 years old.

25. Female lobster holds eggs in her swimmerets.

26. Shrimp Diverse group of crustaceans Found in salt and freshwater
Important food source for humans and marine life

27. Shrimp are scavengers that feed on small pieces of dead plant and animal material (omnivores).
stilton.tnw.utwente.nl/shrimp/shrimp1.jpg

28. CRABS
Small abdomen that is tucked under thorax
Most scavengers
Live along rocky shoreline
Some terrestrial (return to sea only to release eggs)

29. Mouth
Swimming legs

30. Female crab holds eggs in her abdomen.

31. The 2 grasping claws of crabs are also called pincers or chelipeds.

32. Wider abdomen is female
Sexing crabs
Narrow abdomen is male
Wider abdomen is female

33. Class Merostomata horseshoe crabs Book gills for breathing
Mouth parts for piercing called chelicerae
living fossil

34. Blood is used to test for bacteria in pharmaceuticals
Critical food source for migrating shore birds like the red knot
Conservation efforts to ban use of crab meat as bait

35. Pycnogonida Found worldwide Most are small and deep water
Use a "proboscis " to pierce and suck liquid from seaweeds and various invertebrates.

36. The Japanese spider crab is the largest arthropod

37. Fiddler Crabs