1. Arthropod

2. Phylogeny of Arthropods
Arthropoda
Annelids
(worms)
Onychophorans
(worms w/legs)
Chelicerates
(spiders)
Crustaceans
(lobsters)
Insects
(butterflies)
Trilobites
(extinct)
Worm-like
Ancestor

3. General Characteristics segmented body jointed appendages
bilateral symmetry
secreted exoskeleton
molting
open circulatory system
ventral nerve cord and brain
                                                         
                                                                                 

4. Subphylum Trilobita (extinct) Subphylum Chelicerata
DIVERSITY
Numbers
about 80% of all animals are arthropods
estimated to be over 30 million arthropods
far more of them than all other metazoan species combined
in virtually every conceivable environment:
marine, terrestrial, freshwater, and aerial habitats.
Phylum Arthropoda
Subphylum Trilobita (extinct)
Subphylum Chelicerata
Subphylum Crustacea
Subphylum Uniramia (insects)

5. Chelicerata
horseshoe crabs
mostly terrestrial
cephalothorax-abdomen
6 pairs cephalothoracic appendages
chelicerae, pedipalps, 4 pairs legs
no antennae

6. Limulus is a benthic scavenger and predator.
Horseshoe Crab
Limulus polyphemus, Carcinoscorpius rotunda, and Tachypleus gigas.
Limulus is a benthic scavenger and predator.
Prey include clams and other invertebrates that it digs for in the sand.
The tail spine is used as a self-righting mechanism if the animal is overturned accidentally. Lives up to 19 years
Reaches sexual maturity at about 9 to 12 years old

7. Horseshoe Crab
Mates during spring and summer full and new moons, onto ocean beaches.
Females lay up to 30 thousand eggs, which males fertilize before burying them in the sand
These eggs provide a major food source for migrating birds along the Atlantic coast. Those that are not eaten hatch during the next high tide, and the tiny larvae are carried away to sea.

8. Biomedical

10. Blue Blood Harvest

11. Subphylum Crustacea two pairs antennae
marine, freshwater, and terrestrial
Primarily aquatic
Free-floating larval stage
26,000+ known species

12. Subphylum Crustacea brine shrimp Shrimps Crabs Lobsters Copepods
Barnacles

13. Respiration Gills blood is oxygenated by gills
oxygen delivered to tissues by blood
crustacean gills are usually associated with appendages

14. Open Circulatory System
Closed Circulatory System

15. NERVOUS SYSTEM
Side view of body showing relative position of circulatory (yellow), digestive (green), and nervous (blue) systems.

16. SENSE ORGANS
receptors for light, vibrations, chemicals, equilibrium, gravity
cuticle modified to form a vast array of receptors (sensilla)
Mechanoreceptors
Chemoreceptors
Equilibrium and Gravity Statocysts
Tympanal Organs
Hygroreceptors
Photoreceptors
Pigment-cup Ocelli
Compound Eyes

17. Ommatidia Compound Eye Lens Crystalline cone Pigment cells Facet
Visual cells
Nerve fibers from visual cells
Optic nerve
Ommatidia

18. REPRODUCTION
fertilization may be external or internal in aquatic arthropods
always internal in terrestrial species

19. Arthropod Development
Zoea
Nauplius
Megalops

20. Camouflage
Decorator Crab
Sponge crab

21. Camouflage: anemone crab

22. coral guard crabs and pocilloporid corals

23. gall crabs and pocilloporid corals

24. Symbiosis

25. scarlet cleaner shrimp

26. sea cucumber crab and sea cucumbers

27. pompom crabs and sea anemones

28. crabs and sea anemones