ARTHROPODS
Ch. 24
General Characteristics
 Segmented bodies
 Jointed appendages
 Hard external skeleton (exoskeleton
made of chitin)
General Characteristics
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Molting
Open circulatory system
Brain with ganglia
Compound eyes
General Characteristics
 Some aquatic arthropods have gills
 Terrestrial arthropods have trachae
(exchange CO2 and O2 change through
holes called spiracles).
Examples of Arthropods
 560 million years old
 Crustaceans- live in the ocean
 Crayfish, crabs, lobsters, barnacles
 Arachnids
 Spiders, ticks, scorpians, mites
 Insects
 Myriapods- many legs
 Centipedes, millipedes
Extinct Arthropods
 Trilobites
**Horseshoe crabs are the
only closest living relatives.
 Eurypterids
Review
 1) List 3 characteristics of arthropods that
unite them as a single large group.
 2) Name 1 group of arthropod that is now
extinct. Name at least 3 groups still in
existence today.
INSECTS
Keys to Insect Success
 Ability to fly (1 or 2 pairs of wings)
 Diverse feeding habits
 Many types of mouthparts
 Digestive enzymes to eat unusual food
Keys to Insect Success
 Video clip
 Metamorphosis- body form changes from
juvenile to adult
 Larva, pupa, adult
Impact of Insects
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Bees & flowers
Termites & wood
Insect Medicine?
Diseases/ pests
Entomology- study and classification of
insects
Insect Collection
 Some Major Orders of Insects
Lubber Grasshopper
Dissection
Grasshopper Head
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Compound eyes
Simple eyes
Mandible
Palps
Antennae
Grasshopper Thorax
 Tympannic
membrane
 Jumping legs
 Walking legs
 2 pairs of wings
Grasshopper Abdomen
 Spiracles
 Ovipositor (if female)
Grasshopper Internal
Anatomy
Grasshopper Internal
Anatomy