1. Chapter 28: Chapter 28: Arthropods Insects, Crabs, Centipedes, Spiders

2. Taxonomy Kingdom: Animalia ◦Phylum: Arthropoda (jointed feet)  ** More species in this phylum than all other animal phylums**

3. Characteristics Segmented Body Exoskeleton: Protein and Chitin (a carb) Jointed appendages (legs, antennae) Complex organ systems

4. Body Systems A. Digestive ◦- Herbivores, carnivores, omnivores, bloodsuckers, filter feeders, detritivores, parasites ◦- May have mouth with pincers, fangs, or jaws

5. Body Systems Respiratory ◦Aquatic arthropods: feather-like gills ◦Terrestrial arthropods: breathe through TRACHEAL TUBES -Air enters and leaves through small openings in the side of the body (SPIRACLES) -Spiders use book lungs: layers of respiratory tissue stacked like pages of a book

6. Body Systems Circulatory ◦Open circ. Sys ◦Well developed heart

7. Body Systems Excretory ◦Aquatic: diffusion ◦Terrestrial: MALPIGHIAN TUBULES- sac-like organs; extract wastes; add them to feces

8. Body Systems Nervous ◦Well developed nervous system ◦brain; nerve cord; ganglia ◦Sense organs ex) compound eye

9. Body Systems Movement ◦Muscles controlled by nervous system ◦Flex (bend) or Extend (straighten)

10. Body Systems Reproductive ◦Aquatic: Internal or External fertilization ◦Terrestrial:  Internal fertilization  Remote fertilization – EX); Male spider leaves a sperm packet on web for use a t a latter time by the female—sperm bank

11. Body Systems Growth and Development ◦MOLTING: shedding exoskeleton to make a larger one; controlled by endocrine system  ecdysis (molting) The periodic loss of the outer cuticle of arthropods. It starts with the reabsorption of some materials in the inner part of the old cuticle and the formation of a new soft cuticle. The remains of the old cuticle then split; the animal emerges and absorbs water or swallows air and increases in size while the new cuticle is still soft. This cuticle is then hardened with chitin and lime salts. In insects and crustaceans ecdysis is controlled by the hormone ecdysone.ecdysone

12. Groups of Arthropods ** Arthropods are classified based on # and structure of body segments and appendages, especially mouthparts 3 Groups : ◦Crustaceans ◦Spiders ◦Insects

13. . subphylum: Crustacea ** Crabs, shrimps, lobsters, crayfish, barnacles ◦Aquatic ◦2 pairs of antennae ◦2 or 3 body sections ◦Chewing mouthparts (mandibles) ◦Decapods: 5 pairs of legs ◦Chelipeds: 1 st pair of legs = large claws  Example: Crayfish ◦ 1. Body Segments  a. Cephalothorax (head + thorax) - houses organs  b. Abdomen: swimmerets ◦ 2. Antennae: sensory (2 pair) ◦ 3. Mandible: mouthpart for biting/ grinding  Example: Barnacle ◦ - Sessile ◦ - No abdomen or mandible Crustaceans

14. Chelicerata subphylum: Chelicerata ** Spiders and relatives ◦Mouthparts:  1. Chelicerae: contain fangs-stab/paralyze prey  2. Pedipalps: grab prey ◦NO antennae ◦2 body sections  1. Cephalothorax: brain, eyes, mouth, legs  2. Abdomen: internal organs ◦4 pairs of walking legs

15. Chelicerata 2 Main Classes ◦ 1. Merostomata: Horseshoe Crabs ◦ not crabs ◦ marshes, bays, sea coast

16. Chelicerata 2. Arachnida: spiders, mites, ticks, scorpions ◦a. SPIDERS  many spin webs of silk; through spinnerets  some stalk and pounce prey Ex) tarantula  fangs (venom) paralyze; inject digestive juice in wounds to liquefy; suck up

17. Chelicerata 2. Arachnida:continued ◦b. MITES and TICKS  parasitic; attack plants and animals  chelicerae pierce skin  transmit diseases (bacteria) Ex) lyme disease

18. Chelicerata 2. Arachnida:continued ◦c. SCORPIONS  pedipalps enlarged into claws  segmented abdomen with venomous stinger  chew prey

19. Uniramia C. subphylum Uniramia ** Insects and relatives: contains more species than all other groups combined!!  Jaws  One pair of antennae  Unbranched appendages ◦3 Classes  1. Class: Chilopoda A.K.A. CENTIPEDES ◦ Each body segment has one pair of legs ◦ Carnivores; mouthparts have venomous claws ◦ Moist or humid areas

20. Uniramia 2. Class: Diplopoda A.K.A. MILLIPEDES ◦Each body segment has two pairs of legs ◦Eat dead/ decaying plant material ◦Roll into a ball when disturbed ◦Under rocks; in decaying logs

21. Uniramia 3. Class: Insecta A.K.A INSECTS ** 73% of animals alive are insects!! ◦Segmented body: Head, Thorax, Abdomen ◦ 3 pairs of legs attached to thorax ◦Most: 1 pair of antennae; Compound eyes; 2 pairs of wings; Tracheal tubs

22. Uniramia a. Response to Stimuli ◦Compound Eye - Multiple lenses easily detect movement; but see less detail ◦Chemical receptors for taste and smell on mouthparts, antennae and legs ◦Sensory hair ◦Well developed ears – above human range

23. Uniramia b. Adaptations for feeding ◦Produce saliva for breaking down food → Bee saliva breaks nectar into honey! (Bee spit…YUM!) c. Movement and flight ◦Legs (3 pair) ◦Wings (2 pair): made of chitin: allow insects to disperse and colonize

24. Uniramia d. Metamorphosis (2 types) ◦1. Incomplete metamorphosis  Ex) Chinch bug ◦ nymphs (mini adult) : no wings

25. Uniramia d. Metamorphosis (2 types continued) ◦2. Complete metamorphosis  Ex) Lady bug, bee, moth ◦ egg, larvae, pupa, adult: each stage dramatically different

26. Uniramia e. Insects and Humans ◦Negative: crop damage; disease ◦Positive: pollination; products (wax, honey)

27. Uniramia f. Insect Communication  Mostly used for finding a mate ◦1. Visual cues  Ex) Male Firefly: series of light flashes; females signal back (bad news = mimicry  ) ◦2. Chemical signals  Pheromones: chemicals that affect behavior in the SAME species (some alarm or alert)

28. Uniramia g. Insect Societies  Ex) Ants, Bees, Termites ◦ SOCIETY: group of the same species working for the benefit of the whole group ◦1. Castes: Specialized individuals for roles in the society  queens, reproductive males, workers ◦2. Communication within society  each society has a ‘language’ of chemicals, movements, etc ◦ Ex) bees- dance the location of food (p. 733)

29. Uniramia Example of ant communication Example of ant communication: