1. ARACHNIDA

2. Characteristics of a typical arachnid include:
Four pairs of legs (8 legs total)
Four pairs of eyes (8 eyes total)
They have a cephelathorax (a head and thorax fused together)
They don’t have antennas
They perform respiration via book lungs

3. Spider External Anatomy

4. Spider Legs

5. Spider Internal Anatomy

6. Spinnerets http://www.dianamarques.com/images/spinnerets.jpg

8. Silk
Spiders have six spinnerets that can produce up to seven different types of silk.
Spider silk is made of protein and is one of the strongest natural substances in the world.

9. Spiders Ticks Scorpions
Some organisms that are found in the arachnida class are:
Spiders
Ticks
Scorpions

10. ORGANISIMS SPIDER SCORPION TICK Kingdom: Animalia Animalia Animalia
Phylum: Arthropoda Arthropoda Arthropoda
Class: Arachnida Arachnida Arachnida
Order: Araneae Scorpiones Ixodida
Family: Theridiidae Vaejovidae Ixodidae
Genus: Latrodectus Vaejovis AmblYomma
Species: L. hesperus V. brysoni A. ovale

11. AmblYomma ovale
Latrodectus hesperus
Vaejovis brysoni

12. DIAGRAM OF A SPIDER Uses 8 legs to move around
Gets food by trapping it in a web
Can spin webs by using a special silk gland
Can kill prey by using it’s Poisonous fangs (females only)

14. ANATOMY OF A SPIDER
Spiders transport nutrients and oxygen by circulating blood through their bodies
Most arachnids lack muscles in their legs, so they move their legs hydraulically by using the blood pressure in their legs
Spiders exchange gases using an organ called a Book-Lung
book lung is made of several air pockets surrounded by blood filled tissues
Spiders use book lungs to perform respiration
Spiders can not eat their food in solid form
When a spider catches its prey, it turns it into a liquid by using digestive juices produced in its stomach
The spider sucks up the liquid remains and absorbs its nutrients

16. LIFE CYCLE An infant arachnid will hatch from an egg
The infant arachnid grows up into an adult
The adult arachnid will eventually find a mate
An adult male will transfer sperm to a female
Female lays eggs
New arachnids hatch from eggs

17. FUN FACTS Almost all arachnids are carnivores
Spiders eat more insects than birds and bats combined, and play a big role in insect population control
Spiders can regenerate lost limbs, just like reptiles