2. Arthropods are the most
successful phylum on the
planet!
750,000 species
Arthropods have
Segmented body
Tough exoskeleton
Jointed appendages
3. Feeding – complex mouthparts to eat a wide range of food
Respiration
Land – air enters through spiracles – holes in the side of the body.
Water – gills or book gills
Circulation – open circulatory system – open sinuses
Excretion – Malpighian tubules – saclike organ that
combines urine and waste together
Response – have a brain! Sophisticated eyes and taste
receptors
Movement – have muscles…can flex and extend
Reproduction – internal or external reproduction
depending on the species
4. 1. Crustaceans – primarily aquatic
Examples: crabs, shrimps,
crayfishes and pillbugs.
Characteristics:
Two pairs of antennae
2 or 3 body sections –
Cephalothorax/Abdomen
Chewing mouthparts called mandibles
5. Molting – when arthropods
outgrow their exoskeleton
Steps to molting
1. skin glands digest inner
part of exoskeleton
2. other glands create a new
exoskeleton
3. animal pulls itself out of
old skeleton
4. While new skeleton is soft
– animal fills it with air to
allow for growth
6. 2. Spiders and their relatives
Characteristics
No antennae
Cephalothorax and abdomen
2 pairs of mouthpart appendages
Chelicerae – fangs to stab and paralyze prey
Pedipalps – grab prey
Spiders are in the class Arachnida
Spiders have no jaws so they liquify their prey
Scorpions are found in warm climates.
The abdomen has a stinger that can kill
and paralyze prey.
7. 3. Insects –
There are 3 classes of Insects
1. Chilopoda – centipedes
2. Diplopoda – millipedes
3. Insecta – the insects
1. Centipedes –
• each body segment has one pair
of legs
carnivores
live beneath rocks or in the soil
2. Millipedes – each body segment
has two pairs of legs
Dragon Millipede – produces
cyanide when threatened.
8. Insects have a body divided into
three parts
Head – antennae and eyes
Thorax - three pairs of legs, wings
Abdomen – stinger or poison gland
9. Insects undergo metamorphosis – a process of
changing shape and form.
1. Incomplete Metamorphosis – Young (called
nymphs) look very much like the adults.
Examples: Grasshoppers
10. 2. Complete metamorphosis – dramatic change in body
form. Eggs—Larvae—Pupa—Adult
Examples: bees, moths, beetles, butterflies, flies
