Arthropods
Jointed-legged
invertebrates
Arthropod
Characteristics
Chitinous exoskeleton
Paired-jointed appendages
Growth with ecdysis (molting)
Open circulatory system
Complete digestive tract
Exoskeleton
Major reason for success!
Provides
Support
 Protection
 Prevention of dehydration
 Sites for muscle attachment

Metamorphosis
Change body form from immature
(larval) stages to adult forms
Reduces competition between
stages for
Food
 Living space

Taxonomy of
Arthropods
4 subphyla
Trilobitomorpha (all extinct)
 Chelicerata
 Crustacea
 Uniramia

Chelicerata
Horseshoe crabs
Spiders
Mites
Ticks
Scorpions

Crustacea
Shrimp, lobsters, crayfish
 Fairy shrimp, brine shrimp
 Water fleas
 Barnacles

Uniramia
Class Diplopoda
(millipedes)
Class Chilopoda
(centipedes)
Class Hexapoda (insects)
Nervous System
Johnston’s organs (hearing - on
antennae)
Tympanic organs (hearing – on legs
or body)
Compound eyes (facets –
ommatidia – fused)
Simple eyes (ocelli)
Economic Impact of
Arthropods
1. Name one effect each major
group has on mankind (good or
bad).
2. For insects, list 4 good things
that they do and 4 bad things
that they are responsible for.