1. ARTHROPODS ARE ALL AROUND US!

2. CLASSIFICATION OF LIFE

3. KINGDOM ANIMALIA ⇓
PHYLUM ARTHROPODA

4. KEY CHARACTERISTICS Chitinous exoskeleton Segmented bodies
Jointed appendages
Bilateral symmetry
Pair of compound eyes
Brain in dorsal part of head
Ventral nerve cord
Open circulatory system powered by a single heart

5. EXOSKELETON Made up of carbohydrates (chitin) Excellent for protection
Some Crustaceans add CaCO3
Excellent for protection
Waterproof
Efficient movement
Does not grow with the animal
Restricts movement

6. APPENDAGES Antennae Claws Walking legs Wings Flippers
Other specialized features

7. NERVOUS SYSTEM Well-developed
Brain that consists of a pair of ganglia in the head.
Compound eyes
Sense organs
>statocysts (help maintain balance)
>chemical receptors

8. CIRCULATORY SYSTEM Open circulation
Heart long and narrow and stretches along the abdomen
When heart contracts, it pumps blood through arteries that branch into smaller vessels and enter the tissues.
From the tissues, blood leaves the vessels and moves through spaces in the tissues called sinuses.
Eventually, blood collects in a large cavity surrounding the heart, from which it re-enters the heart through small openings and is pumped around again.

9. RESPIRATORY SYSTEM
takes place through the body surface, and/or by means of gills, tracheae, or book lungs.
-some completely lack specialized respiratory organs

10. REPRODUCTIVE SYSTEM Dioecious (separate gonads in males and females)
Fertilization is internal in terrestrial forms; can be external in some aquatic
Most lay eggs
-development often proceeds with some form of metamorphosis
- Parthogenesis in some (eggs hatch without being previously fertilized)

11. FEEDING
Herbivore
Carnivore
Parasite
Filter feeder
Detritus feeder

12. DIGESTIVE/EXRETORY SYSTEM
Undigested food becomes solid waste and leaves through anus
Dispose of N-containing waste by Malpighian tubules (bathed in blood inside body sinuses)
-remove waste from blood, concentrate them, and then excrete via anus
Complete gut

13. ARTHROPODA & SUBPHYLA

14. 4 MAJOR SUBPHYLA Class Trilobita (extinct) Class Crustacea
Class Uniramia
Class Chelicerata (Cheliceramorpha)

15. SUBPHYLUM TRILOBITA Extinct 245 million years ago
First appeared 540 million years ago
Closest living relative is the horseshoe crab
First animals with colour vision
Detritus feeders off ocean floor
Some were predatory

16. TRILOBITA
Triarthrus
Lichas
Paradoxides

17. SUBPHYLUM CRUSTACEA
Include brine shrimp, crabs, water fleas, lobsters, barnacles and their relatives, etc.
Primarily marine (salt water)
Very diverse group
Not very successful on land

18. CRUSTACEANS Not very successful on land:
-lack of a waxy, water-tight cuticle
-gills for respiration
-larval stage

19. CRUSTACEANS
Hard exoskeleton
Two pairs of antennae
Mandibles

20. CRUSTACEANS
Gills
-look like a row of feathers just under the exoskeleton
-formed from part of the same appendages that form mouthparts and legs
-movement of mouth parts and other appendages keeps a steady stream of water moving over the gills.

21. CRUSTACEANS
Hairy hermit crab

22. CRUSTACEANS
King Crab
Dungeness Crab

23. CRUSTACEANS
Coonstripe/dock shrimp

24. CRUSTACEANS
Japanese spider crab spans up to 4 m (13 ft.). It is the largest arthropod

25. SUBPHYLUM UNIRAMIA Largest group
Includes insects, millipedes, centipedes, and their relatives
One pair of antennae and appendages that do not branch (uniramous appendages)

26. From spiracles, have long branching tracheal tubes that reach deep into the animals’ tissue.
Network of tracheal tubes supplies oxygen by diffusion to all body tissues.
Work well in small animals

27. UNIRAMIA - CLASS DIPLOPODA: MILLIPEDES
Harpaphe haydeniana
Octoglena anura
Californiulus euphanus
Characterized by long, wormlike body composed of many
leg-bearing segments – are mainly detritivores

28. UNIRAMIA - CLASS CHILOPODA: CENTIPEDES
Scutigera coleoptrata
“house centipede”
Scolopendra
Lithobius forficatus
Characterized by long, wormlike body composed of many leg-bearing segments – are mainly predators

29. UNIRAMIA - CLASS INSECTA
CHARACTERIZED BY: three part body:
-head, thorax and abdomen
-has three pairs of legs attached to the thorax.
INSECT COMMUNICATION:
Use sound, visual, chemical (pheromones)
and other types of signals.

30. UNIRAMIA SUBPHYLUM CHELICERATA
includes arachnids, horseshoe crabs, ticks and numerous other animals which have become extinct ever since the Paleozoic era
second most prominent class
predators, parasites, or decomposers
do not care for their young
producing large numbers of offspring

31. CHELICERATA Live on land (except horseshoe crab) Lack antennae
Presence of chelicerae (mouth parts modified to grasp food or to poison prey with venom)
Most have pedipalps (2nd pair of appendages near mouth)
2 body segments
Six appendages
Other features: book lungs, telson, spinnerets, stingers

32. Horse shoe crabs:
-book gills
Spiders and relatives:
-book lungs
-contained inside a sac within the body
-opening (spiracle) connects sac containing book lungs with fresh air outside.
-both of these structures several sheets of tissue are layered like pages in a book.
>increase surface area for gas exchange

33. CHELICERATA CLASS ARACHNIDA
Smeringurus mesaensis
Argiope bruennichi
Dermacentor occidentalis

34. HOW ARTHROPODS FIT INTO THE WORLD:
Direct and indirect source of food
2/3 of flowering plants depend on insects for pollination
Symbiotic relationships
Agriculture
Medications - allantoin heals wounds (maggots produce)
Chemicals
Famines and illnesses