1. Arthropods & Echinoderms

2. Common Characteristics
Invertebrate
Exoskeleton- Skeleton on the outside.
Protection
Helps keep in moisture
Segmented Body
Some body segments are specialized
Jointed attachments- Arthros- means jointed / pod – foot or leg.
Legs- allows flexibility to move
Jaws

3. Major Classes Crustaceans (crabs, lobsters) Arachnids (spiders, ticks)
Diplodata (millipedes)
Chilopoda (centipedes)
Insecta (insects)

4. Crustaceans 5 or more pair of legs
Breath through tubes that allow air to enter through exoskeleton.
Only arthropods to have two pair of antennae.
Most have compound eyes (multiple lenses).
Most start off life as larvae and go through metamorphosis. (dramatic changes).
Mostly live in water, but a few can even live in trees.
Some are scavengers, other predators, and still other like the Krill are herbivores.

5. Arachnids characterisitcs
Two body sections
The first section is a combines head and chest
The second is the abdomen which has the reproductive organs and most of the digestive system.
Eight legs
No antenna

6. Arachnids - types
Spiders- all are predators, hollow fangs that inject venom.
Mites- Mostly parasites.
Ticks- All parasites.
Scorpions- Predators with a stinger on the tail.

7. Centipedes Centi- 100 pedes – feet 100ft
Predators- sting and inject venom in prey
Highly segmented bodies.

8. Millipedes Highly segmented Two pairs of feet per body segment
Most are herbivores

9. Insects characteristics
Three body segments
Head- compound eyes (many lenses)
Thorax – where wins are attached
Abdomen – reproduction organs- digestive system.
Six legs
One pair of antenna
Usually one or two pairs of wings
Breath through tubes that allow air to enter through exoskeleton.

10. Insect metamorphosis
Complete metamorphosis- egg larva (caterpillar or maggot) pupa (chrysalis or cocoon) adult.
Gradual metamorphosis- egg nymph (smaller version of the adult) adult.

11. Feeding / Defense Insects feed in a wide variety of ways:
Herbivores
Scavengers
Parasites
Nectar
They defend themselves in many ways also:
Run or fly away
Smell or taste bad
Sting
Camouflage

12. Insects good or bad Most insects are beneficial or are harmless
Help to pollinate crops
Make silk
Prey on other harmful insects
Some insects are a nuisance
Need to be controlled
Insecticides
Introduce natural predators
Other methods such as bacteria to control certain pests.

13. Communication
Pheromones- (a chemical agent) are used by insects to communicate.
Bioluminescence- using light to communicate such as fireflies.

14. Echinoderms Echino- Spiny / Derm – Skin
Endoskeleton – internal made of plates.
Radial symmetry- usually in multiples of five
Types
Sea Stars
Brittle Stars
Sand dollars
Sea urchins
Sea Cucumbers