MOUNTAIN POINTE HIGH
Animals of Phylum Arthropoda
Termites, ticks, scorpions, grasshoppers,
flies, mosquitoes, lobsters, crabs,
bugs,spiders, centipedes, millipedes,
bees, wasps, daddy-long legs, mites,
fleas, trilobites, butterflies, moths,
barnacles, ants,……..and many many
*ARACHNID - SPIDER
*CRUSTACEAN - LOBSTER, SHRIMP
*INSECTA - BEE, GRASSHOPPER
*CHILOPODA - CENTIPEDE
*DIPLOPODA - MILLIPEDE
Characteristics of Arthropods !!
Invertebrates with an exoskeleton!
Jointed appendages (legs)
Bilaterally symmetrical, protosome
Has a true coelom, mesoderm
What are the advantages or disadvantages
of an exoskeleton??
Protection -made of chitin and
protein- hard and thick !!
Supports internal organs
Provides for muscle attachment
Can’t grow, so it must be shed
by molting periodically!
Most arthropods have three
body segments! HEAD,
THORAX, and ABDOMEN
Sometimes the head and thorax
are fused together to form a
CEPHALOTHORAX- like in
How do Arthropods breathe??
Some land Arthropods breathe through tiny openings
on their body called spiracles which lead to tubes
within the body called tracheal tubes! - crickets!
Other land arthropods (spiders) breathe using book
lungs found just behind the legs on the body!
Senses found in Arthropods!- from a brain
and ventral nerve chord!!!
Antennae are sensitive to movement, sound and chemicals!
They are used for communication too.
Pheromones are chemical-odor signals given off by
EYES - both simple and compound! (Simple eyes detect
light/dark! Compound eyes have many lenses together
forming an image! Excellent for detecting movement!)
Sight through a Bees Compound Eye
Circulation and Digestion in Arthropods!
Open circulatory system- blood flows into spaces in
the body- not kept in blood vessels!
Dorsal heart !
Complete digestive system-mouth-crop-stomach-
Digestive enzymes breakdown food!
Chewing mandibles , or sucking mouth parts are
Malpigian Tubules filter wastes into the intestines!
Sexual Reproduction in Arthropods !
Internal Fertilization- eggs protected inside female.
A few are hermaphrodites
Some show parthenogenesis- young forming from
Arthropods and Humans ??
The Good, the Bad and the
Great pollinators …bees, wasps!
Provide honey, shellac, wax and silk!
Alternative to pesticides - lady bugs, praying mantis
Used in genetic research to make artificial skin,
surgical sutures, and anti-fungal medicine from crab
Problems: eating our food!
Spread diseases- malaria, yellow fever!
Diversity - The Arachnids!!-
spiders, scorpions, mites, and ticks!
30,000 species of spiders - but only about a dozen are
poisonous to humans!
2 body parts - cephalothorax and abdomen!
Appendages- 2 Chelicera-fangs, two pedipalps for
handling food and used in reproduction, and 8 legs!!
2-6 silk glands in the abdomen-passing the liquid silk to
the spinnerets which knit it into thread!
No mandibles - but a sucking stomach!
No antennae / Simples eyes -usually 8
Diversity - The Crustaceans -
crayfish, shrimp, lobsters, barnacles, crabs!
Gills for breathing
Large mandibles for crushing food!- jaws open side to
side not up and down!
2-pairs of antennae!
2 stalked compound eyes!
5 or more pairs of walking legs with 2 large chelipeds
No malpighian tubes --> mouth and anus
Crustacean Example - Crayfish
Diversity-Centipedes and Millipedes
Class Chilopoda- centipedes with one pair of legs per
Centipedes are carnivorous- eating snails, slugs and
worms- They bite!!
Class Diplopoda - millipedes with two pairs of legs per
Millipedes are herbivorous - eating roots and leaves
Millipedes don’t bite but they can spray a smelly-fluid
from their stink glands!
The young is a The young looks
small version totally different
of the adult from the adult
version. Ex. Larva
Ex. Egg - - Pupa
nymph - adult
3-body parts- head-thorax-abdomen
Spiracles-tracheal tubes for breathing
3-pairs of legs- antennae, both simple and compound
A tympanum for hearing
Sometimes wings- one or two pair
Complete Metamorphosis- (butterflies-moths) egg-
Incomplete Metamorphosis-( crickets, grasshoppers)
Complete Vs Incomplete Metamorphosis