4. General Characteristics
• Bilaterally Symmetrical
• Cells form up to the size of tissues and organs. Eat everything from plants to
animals
• Live everywhere in land, fresh water, salt water, and every other
environment
• Largest Phyla on earth
• More than 83% of all described animal species are arthropods
5. Support System
Exoskeleton - made of protein and
chitin
• used for protection
• keeps joints attached
Molting - sheds exoskeleton as it
grows
Segmented body
• Head, thorax, abdomen
Contain a range from 3 to 300 sets
of legs
Contain 2 pairs of antennae
6. Respiratory System
• Aquatic arthropods possess gills for respiration
• Land arthropods have a tracheae and book lungs
as respiratory organs
• Air passes through the tracheae through
specialized openings in the exoskeleton called
spiracles
7. Circulatory System
• Open Circulatory System
• Body fluid called Hemolymph (Not blood)
• Hemolymph is pumped by the heart to sinuses called the
hemocoel
• Body fluid enters pores to the organs and is propelled through
arteries to the body
8. Nervous System
• Brain
• Ventral nerve cord
• Double chain of ganglia
along the ventral surface of
the arthropod
• At anterior end are 3 fused
pairs of dorsal ganglia,
constitutes the brain
• Much of the control of
arthropod's activities is in
the central ganglia
9. Digestive System
Eat Everything
Complete digestive system
Specialized by segmentation
Food enters through the mouth and flows into the mid-gut
where food is broken down and pushed to the anus.
Specialized mouthparts
piercing, sucking or mandible, biting, chewing
10. Excretory System
Excretory system made of
malpighian tubules and
green glands
Malpighian tubules are
tubular network that
collects liquid wastes and
sends them to the hind gut
in the form of nitrogenous
wastes. Found in terrestrial
arthropods .
Green glands collect and
excrete urine like kidneys.
Found in aquatic
arthropods.
11. Reproductive System
• Most reproduce sexually
o Internal fertilization
o External fertilization
• Some species reproduce through parthenogenesis
e.g. bees, wasps, ants and aphids
• Undergo metamorphosis
Complete egg – larva – pupa – adut
Incomplete egg – juvenile – adult
14. Chelicerata
• Lives on land or in water
• Includes horseshoe crabs, spiders, scorpions,
ticks and mites
• Have chelicerae, which serve as pincers or
fangs
• They do not have antennae
15. Myriapods
• All Myriapods lives on land
• Head contains 3 appendages
for eating including
mandibles (jaw like
structure)
• Millipedes
o less than 1000 legs (2 pairs
per segment)
o herbivores
• Centipedes
o 1 pair of legs per segment
o carnivorous
16. Crustaceans
• Live in fresh and salt water
environments
• Crustacea is Latin word for
"Shell"
• Shell is made of calcium,
protein, and chitin
• Have anywhere from 16 to 60
segments, 2-3 pairs of legs
• Advanced crustaceans have
pincers
• Includes Crabs, Lobsters,
Barnacle, Shrimp
17. Hexapoda
• Includes insects
• Mostly live on land
• Contain 3 pairs of legs and2 pairs of wings
• There are more species of Hexapoda than all other
forms of life combined
