1. Phylum Arthropoda Non-insects

2. Characteristics Makes up 3/4's of all animal species
Includes insects, spiders, scorpions, millipedes, centipedes, crabs, lobsters, & crayfish
Arthropod means "jointed foot"
Jointed appendages (legs, antenna, mouthparts)
Segmented body with paired appendages on each segment)
External exoskeleton made of chitin (carbohydrate) & protein for protection & support
Exoskeleton has 3 layers --- outer waxy layer repels water, middle layer has calcium for extra strength, & inner layer has flexible joints for movement
Protostomes (blastopore develops into mouth)
Coelomate (mesoderm-lined body cavity)
Ventral nervous system
Open circulatory system
Specialized sensory receptors & high degree of cephalization
Have simple or compound eyes & segmented antenna

3. Movement & Growth
Muscles occur in bundles & are attached to inside of exoskeleton on each side of joints
Exoskeleton must be periodically molted (shed) for organism to grow
Molting called ecdysis
Tissues swell and put pressure on old exoskeleton
Molting hormone released & causes epidermal cells to secrete enzymes that digest & loosen inner exoskeleton
New exoskeleton secreted by epidermal cells flexible at first & must harden so arthropod not vulnerable to predators so often stay in hiding after molting
Arthropods go through numerous molts

4. Butterfly Molting Pupal Case

5. Evolution & Taxonomy
Evolved from ancestral arthropod with many body segments each with appendages
Modern arthropod segments fused into larger, specialized structures called tagmata
Four subphyla       * Trilobita - extinct trilobites      * Crustacea - shrimps, lobsters, crayfish, & barnacles      * Chelicerata - spiders, scorpions, & ticks      * Uniramia -centipedes, millipedes

6. Subphylum Trilobita Characteristics
Includes extinct trilobite
Marine
Have a head & segmented trunk with one pair of legs on each segment
Breathe through gills
Single pair of antenna

7. Subphylum Chelicerata Characteristics
Includes 2 classes --- Xiphosura or Merostomata (horseshoe crab) and Arachnida (spiders, ticks, scorpions, & mites)
Have a cephalothorax (fused head& thorax) and abdomen
No antenna
Simple eyes or ocelli
Have 6 pairs of jointed appendages:      * Chelicerae - claws or fangs (1 pair)      * Pedipalps - used for feeding, walking, sensing, transferring sperm (1 pair)       * Walking legs - movement (4 pairs)

8. Class Merostomata
Horseshoe crab   * Marine   * Not true crabs   * Fanglike pincers or chelicerae   * Use book gills to breathe

9. Class Arachnida Terrestrial
Body divided into a cephalothorax and abdomen
The cephalothorax usually has six pairs of jointed appendages      * Four pairs of legs      * Chelicerae or fangs with venom      * Pedipalps
* No antenna
Breathe by book lungs &/or tracheal tubes

10. Spiders Arachnid that feeds on insects (carnivores)
Have oval shaped, unsegmented abdomen
Cephalothorax connected by narrow waist to abdomen
Have 8 simple eyes or ocelli
Fangs pierce prey, inject poison, & suck out body fluids 
Pedipalps on head help sense prey & move it to the mouth
Open circulatory system
Ostia are openings in heart where blood reenters
Body cavity called hemocoel
Hemocycanin is oxygen-carrying pigment in blood
Have silk glands to make silk & spinnerets to release silk for webs
Breathe by book lungs & tracheal tubes
Malpighian tubules filter wastes & reabsorb water                          

11. Spiders cont… Adaptations for a predatory life on land
Book lungs = paired sacs in the abdomen with many parallel folds that resemble the pages of a book. The folds in a book lung provide a large surface area for gas exchange. (and/or)
Tracheae = a system of tubes that carry air directly to the tissues from spiracles in the exoskeleton.

12. Spiders cont…
3. Malpighian tubules = hollow projections of the digestive tract that collect body fluids and wastes and carry them to the intestine. After most of the water is absorbed, the wastes leave the body in a nearly solid form with the feces. This helps spiders conserve water. And/Or 4. Coxal glands = organs that remove wastes and discharge them through openings at the base of some of the legs.

14. Ticks & Mites Parasitic arachnid Fused cephalothorax & abdomen
Most abundant arachnid
Need blood meal to molt
Mites can damage fruit & feed on dead skin at base of hair follicle (extremely small parasitic or free-living)
Ticks carry Lyme disease & Rocky Mountain Spotted Fever (range in length from a few millimeters to a little over 1inch and are parasitic)

16. Dust Mites

17. Scorpions
Have a cephalothorax & long segmented abdomen curled over body
Prefer dry regions
Poisonous stinger on end of abdomen
Breathe through book lungs
Pedipalps modified into claws
Nocturnal predators

18. Scorpion

19. Subphylum Crustacea Characteristics cont…
Marine members include shrimp, lobster, copepods, barnacles, & crabs
Terrestrial crustaceans called isopods include pillbugs & sowbugs
Freshwater members include crayfish & Daphnia (water fleas)

20. Subphylum Crustacea Characteristics
Have two pairs of appendages on their head that serve as feelers
Usually have appendages on most other body segments
At least some of the appendages are branched
All have jaws or mandibles for chewing or tearing
Known as mandibulates
Have cephalothorax & abdomen
16 to 20 body segments
Have 10 pairs of jointed appendages
Most breathe through gills
Most have a nauplius larval stage
Aquatic crustaceans often incorporate large amounts of calcium carbonate into their exoskeleton

21. Subphylum Crustacea Examples
Barnacles      * Marine       * Sessile crustaceans that live in limestone case       * Filter plankton with appendages called cirri

22. Isopods (pillbugs & sowbugs)
Live on land in dark places
Have 7 pairs of legs on a segmented body
Can roll into a ball for protection

23. Crayfish
Cephalothorax made of 13 fused segments & covered by protective carapace
Antennules located on head help in balance, touch, & taste
Statocysts - balancing organs at the base of antennule
Antenna on head used for touch & taste
Maxillae - paired mouthparts that move side to side to tear food
Maxillipeds - help hold food
Chelipeds - claws used to capture food & for protection
Mandibles - jaws that move up & down to crush  food
Walking legs - 8 pairs used for movement
Swimmerets - under abdomen to swim, gas exchange, & protect eggs/young
Abdomen ends in flat segment called telson with flat uropods on each side

24. Crayfish cont… Compound eyes on stalks
Chitinous teeth in stomach grind food
Wastes leave through anus
Green glands filter wastes from blood & help with salt balance
Open circulatory system with heart to pump blood to gills & body cells
Ostia - one way valves allowing blood from dorsal sinus to reenter heart
Gills attached to walking legs
Separate sexes that mate in fall & sperm stored in seminal receptacle
Eggs attach to swimmerets of female & hatch in several weeks

25. Crayfish cont… Know functions of appendages pg. 749
Digestion = food passes through the esophagus to the stomach, where teeth made of chitin and calcium carbonate grind the food into a fine paste. The paste is mixed with enzymes from the digestive gland then it enters the intestine and the digestive gland for further digestion and absorption. Indigestible material leaves through the anus

26. Crayfish cont…
Respiration = as a crayfish walks, its legs circulate water across its gills. Feathery branches on the posterior pair of maxillae also help direct water over the gills. Each gill is covered by an extension of the exoskeleton that is thin enough to permit gases to diffuse across the gill surface.

27. Crayfish cont…
Circulation = the dorsal heart pumps hemolymph into several large vessels that carry it to different regions of the body. Hemolymph leaves the vessels and enters the gills, where it exchanges carbon dioxide and oxygen with the water. From the gills, the hemolymph returns to the dorsal part of the crayfish and enters the heart.

28. Crayfish cont…
Excretion = water constantly enters the tissues of a crayfish by osmosis. This excess water is eliminated by green glands. The dilute fluid is collected by the green glands leaves the body through a pore at the base of the antennae.

31. Copepods Largest group of crustaceans
Make up most of the marine plankton
Serve as food for many marine animals
Found in freshwater, marine, & moist terrestrial environments

32. Subphylum Uniramia Characteristics
All have antenna, mandibles (jaws), & unbranched appendages
Single pair of unbranched antenna
Includes 3 classes --- Chilopoda (centipedes), Diplopoda (millipedes), & Insecta
Known as myriapods “many feet”
Most are terrestrial
Exoskeleton prevents desiccation (water loss)

33. Class Chilopoda Terrestrial centipedes
Flattened body with longer legs for fast movement
Have 1 pair of legs per body segment
Predators
Mandibles & maxilla for chewing prey (insects & earthworms)
Claw-like appendages or pincers on 1st body segment that can inject venom
Can coil up for defense

34. Centipede

35. Class Diplopoda Terrestrial millipedes
Have 2 pairs of legs per body segment
Rounded body
Scavengers on decaying vegetation as they burrow through soil
Roll into ball when threatened & spray noxious chemical containing cyanide

36. Millipedes