Arthropods
Kinds of Arthropods
Classified by the body parts they have
– Number of legs
– Type of eyes
– Type of antennae
• Antenna: feeler that senses touch, taste or
smell
Groups of Arthropods
1.
2.
3.
4.
Centipedes and Millipedes
Crustaceans
Arachnids
Insects
Centipedes & Millipedes
One pair of antennae
Hard head
One pair of mandibles
– Mandibles: mouthparts that can pierce and suck
food
Centipedes: One pair of legs on each
segment
Millipedes: two pairs of legs on each segment
Crustaceans
Ex: shrimps, barnacles, crabs, lobsters
Most live in water
Gills for breathing; under exoskeleton
Mandibles for eating
Two compound eyes, each located at
the end of an eyestalk
Two pairs of antennae
Crayfish External Features
Arachnids
Ex: spiders, scorpions, mites, ticks
Two body parts: cephalothorax,
abdomen
– Cephalothorax: made up of head and
thorax
Most have four pairs of legs (8 legs)
Claw-like mouthparts called chelicerae
Simple eyes (number varies)
Insects
Largest group of arthropods
Three main body parts: head, abdomen,
thorax
Compound eyes
Mandibles
Six legs
Two antennae
Some don’t have wings; some have one or
two pairs of wings on the thorax
Complete Metamorphosis
Most insects do this
Four stages:
– Egg
– Larva
– Pupa
– adult
Incomplete Metamorphosis
Ex. Grasshoppers & cockroaches
Less complicated than complete
metamorphosis
Three main stages:
– Egg
– Nymph: shed their skin (molting) to grow
– Adult