1. Arthropods contin…
…..or “the most successful animals of all time”.

2. Quick Review…..

3. Main Characteristics Jointed appendages Segmented body
Exoskeleton (skeleton on outside)
Mandibles – chewing mouthparts
Metamorphosis ( egg - larva - adult)
Classification
Kingdom Animalia , Phylum Arthropoda
         

4. Common Features of Arthropods
Molting: shedding of cuticle in order to secrete a larger one. Makes the arthropod vulnerable.
Open circulatory system: blood flows through open spaces.
Malpighian tubules: excretory organs that remove waste from blood in the circulatory system (most arthropods)

5. Unique Arthropod Features (cont.)
Antennae: sensory organs that come in pairs on the organism’s head
Compound eyes: eyes with many parts and multiple separate focusing elements

6. Bilateral Symmetry

7. Chelicerates Spiders, ticks and scorpions
2 body segments                         cephalothorax, abdomen
8 legs
No antenna
Spiders belong to a special group called *Arachnids

8. Brown recluse bites cause necrosis (death of tissue).

10. Fisher Spider: Catches prey, paralyzes them,
pumps in digestive enzymes,
then sucks out predigested contents.

11. Are spiders really dangerous?
Most people fear spiders without good reason
Spiders are allies of humans in our battle with pest insects
Spiders are food for other organisms.
Spider venoms show promise in the field of medicine.
Spider silk is among the strongest, most elastic of natural fibers. Synthesized spider silk has created strong parachutes and bullet-proof vests

12. Crustaceans Shrimp, lobsters, crabs, crayfish 4 pairs of legs
2 claws (chelipeds)
2 pair of antennae

13. Subphylum Uniramia
Millipedes
Centipedes
Insects

14. Centipedes & Millipedes
Predators, poisonous
1 pair of legs per segment
Millipedes
Herbivores
2 pair of legs per segment

15. Insects 3 pairs of legs 1 pair of antennae
3 body segments (head, thorax, abdomen)
Compound eyes

16. Respiration:
Spiracles: openings in exoskeleton that allow air to enter tracheal system (insects only)

17. Reproduction Life Cycle
Metamorphosis: process of changing shape and form

18. Incomplete Metamorphosis
Young are similar to adults, but have different body proportions and are smaller. There are a series of molts that eventually lead to the organism reaching full size.
Adult -> egg -> nymph -> nymph -> adult…
•Nymph is a ___________

19. Complete Metamorphosis
There are several distinct stages:
Larval stage - specialized for eating and growing
Pupal Stage - actual change occurs
Adult stage - specialized for reproduction

20. Beneficial Insects
More than 100,000 species of insects are found almost everywhere in North America, but very few are harmful.
Insects are important to the food chain, pollination, honey, wax, shellac, silk, food, scavenging, and decomposing.

21. Save the Bees from Colony Collapse Disorder
Pollinators
Waggle Dance

22. Review Questions What type of symmetry do arthropods have?
In what stage of metamorphosis does abrupt change occur?
What do most spiders use to breathe?
What process allows arthropods to shed their cuticle in order to grow a larger one?