ARACHNIDA

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

Spider External Anatomy

Spider Legs http://www.uky.edu/Agriculture/CritterFiles/casefile/spiders/anatomy/leg.png

Spider Internal Anatomy

Spinnerets http://www.dianamarques.com/images/spinnerets.jpg http://www.pbrc.hawaii.edu/bemf/microangela/mspigot7o.jpg

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.

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

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

AmblYomma ovale Latrodectus hesperus Vaejovis brysoni

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)

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

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

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