1. Phylum Arthropoda

2. Typical Arthropod Structures Means “Joint-foot” Includes lobsters, crabs, spiders, insects, millipedes, & centipedes Bodies w/segments containing appendages any structure that grows out of the body. Segments include: head, thorax, & abdomen. Exoskeleton made of chitin Bilateral symmetry w/cephalization Must molt (shed exoskeleton) to grow.

3. Arthropod Respiration Efficient respiratory system Three types: –Gills – used to exchange gas in water – Tracheal tubes – branching networks of hollow air passages where air enters through spiracles on the thorax and abdomen. –Book lungs – air-filled chambers that contain leaf-like plates.

4. Arthropod Senses Very acute senses Use antennae for sound and odor communication with pheromones. Accurate vision is important. Most have a compound eye with many lenses and several simple eyes that is only one lens. Well developed nervous system w/double ventral nerve cord, anterior brain and several ganglia.

5. Other Body Systems Open circulatory system Complete digestive system with mouth, stomach, intestine, and anus. Mouth parts contain one pair of mandibles shaped differently for type of food eaten Excrete waste through Malpighian tubules Separate sexes that reproduce sexually, internally for land types and externally for aquatic species. A few species are hermaphrodites and some can reproduce asexually through parthenogenesis.

6. Sub-phylum Trilobita Ancient sea dwellers that are now extinct

7. Sub-phyla Chelicerata Spiders, ticks, mites, scorpions Major class – Arachnida Body parts –Cephalothorax – thorax & head –Abdomen – contains 6 pair of appendages Chelicerae, pedipalps, 4 pr. of walking legs Chelicerae are modified into fangs –Spinnerets produce silk –Book lungs w/trachea to respire. –Malpighian tubules used to remove waste

8. More Information Spiders are carnivores. Most deadly –black widow & brown recluse Scorpions larger pincher-pedipalps, stinger on tail, hunt at night & glow under a black light. Photos by Jon Zawislak

9. We are still in Kingdom Animalia Mites & ticks are the most abundant type of arachnid They have a fused cepahlothorax & abdomen Parasites – mites larvae are the chigger Ticks transfer diseases & sickness American Dog Tick (B. Newton, 2003 )

10. Sub-phylum Crustacea Water fleas, Japanese spider crab, crabs, barnacles, pill bug, sow bug, crayfish, lobster Body –Cephalothorax-head & thorax covered w/carapace –Abdomen – tail-telson; flat paddle on tail Appendages – attached to each segment –Antennules-feelers, touch, taste, equilibrium –Long Antenna – feelers, touch, taste –maxillae – manipulate food/draw in water –maxillipeds – manipulate food, touch, taste –Mandible – chew food –Cheliped – capture food, defense –Swimmerets – reproduction to hold zygotes

11. Crayfish Diagram

12. Other Features of Crustaceans Two opening digestive tract Breath through gills Excess water leaves through green glands

13. Sub-phylum Crustacea Horseshoe crabs Living fossils Live in deep costal waters where they forage on sandy or muddy ocean bottoms Migrate to shallow waters for mating. (Encyclopedia Britannica)

14. Sub-phyla Uniramia Millipedes, centipedes, & all insects

15. Class Diplopoda Millipedes are detritus feeders Two pair of legs per each body segment except last two “Milli” means 1000. Can spray foul- smelling fluid as means for defense. Fire Photo: Rob Rausch

16. Class Chilopoda Centipedes are carnivores One pair of legs per body segment Poisonous “centi” means 100 Giant Desert Centipede Photo: Andrew Loehman

17. Class Insecta Three body parts –Head –contains modified mouth parts –Thorax – 3 pr. of legs –Abdomen –stingers Malpighian tubules – rid waste Proboscis – long tongue for getting nectar. Insects have separate sexes w/internal fertilization Bilateral symmetry w/cephalization

18. Insect Tidbits Insects have to molt in order to grow. Metamorphosis - a developmental change in form. –Two types. Complete-egg-larva- pupa-adult Incomplete-egg-nymph- adult Butterfly-caterpillar, fly- maggot, beetle-grub Use camouflage, bad taste, stingers, & mimicry for defense Communicate w/pheromones Social Insects live & work together.