Arthropods
Molly, Isaiah, Holly, Sean
Body Symmetry

Bilateral
http://biologytricks.blogspot.com/2012/05/anim
al-kingdom.html
Locomotion
Segmented legs
 Some have wings
 Are adapted to live in almost any habitat

◦ Aquatic, terrestrial, air

Smooth muscles
Nervous System
Dorsal brain and ventral nervous cord
 Chains of ganglia serve various parts of
body
 The brain is made of 3 parts

Digestive System
One way
 Have digestive glands

◦ Special because not present in many
organisms
Excretory System
Present
 Malphigian tubules

◦ Projections of the digestive tract
◦ Help conserve water
Circulatory System
Dorsal vessel
 Open system
 Alary muscles on each side of chamber
 Peristaltic contractions move hemolymph

http://www.cals.n
csu.edu/course/e
nt425/tutorial/cir
culatory.html
Respiratory System
Spiracles in exoskeleton
 Flap like valves
 Tracheal trunk and tubes
 Tracheole acts as a filter

http://www.cals.ncsu.edu/cour
se/ent425/tutorial/respire.htm
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http://www.cals.ncsu.edu/cou
rse/ent425/tutorial/respire.ht
ml
Skeletal System

Exoskeleton
◦ Provides a lot of space for movement (joints,
anchor for muscles and appendages)
◦ Provides protection
◦ Composed of chitin

Other species exoskeletons are
composed of lipids, proteins, and calcium
carbonate
Skeletal System (Con’t)

Allows for very little growth
◦ Forces organism to molt (shed)
After exoskeleton molts the organism is
exposed and vulnerable until new shell
hardens
 After molt the organism often hides for
protection

◦ metabolism slows down during hiding
Reproductive system
Separate sexes (male and female)
 Gonads connected directly to ducts
located on the ventral surface of the
trunk
 Sperm is transferred to female within seal
packets called spermatophores

Reproductive Sys.(Con’t)

Spermatophores
◦
◦
◦
◦
Little containers of sperm
Not diluted in aquatic areas
Sometimes deposited directly in the female
Some insect or arachnids deposit on ground
and leave a chemical signal to attract the
female
Class: Crustaceans
Crabs, lobsters, shrimp, wood lice
 Generally aquatic
 5 pairs of legs
 Crush prey with claws

Class: Centipedes
One pair of legs per segment
 Nickname: “hundred-leggers”
 Poisonous
 Hunters

◦ Vomit on their prey to liquefy them
Class: Millipedes
2 pairs of legs per segment
 Nickname: “thousand-leggers”
 Scavenge for decaying plant material,
leaves, etc

◦ Detrivores

Non-poisonous
Class: Arachnids
Spiders, scorpions, mites
 2 body segments
 8 legs
 Carnivorous

◦ Feed on predigested bodies of insects and
other small animals
◦ Drink the blood and insides
Class: Insects
Examples: Flies, bees, ants
 Three body segments

◦ Head
◦ Thorax
◦ Abdomen

Six legs
Phun Phylum Phacts
Compound eyes
 Tough exoskeleton made of chitin
 Called “joint-legged” because they have
segmented legs
 84% of animals are arthropods

Works Cited
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
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Barnes, Robert D. "Arthropod (animal Phylum)." Encyclopedia Britannica
Online. Encyclopedia Britannica, n.d. Web. 03 Oct. 2014.
Barnes, Robert D. "Reproductive System and Life Cycle." Encyclopedia
Britannica Online. Encyclopedia Britannica, n.d. Web. 01 Oct. 2014.
"CIRCULATORY SYSTEM." Circulatory System. N.p., n.d. Web. 03 Oct. 2014
"RESPIRATORY SYSTEM." Respiratory System. N.p., n.d. Web. 03 Oct. 2014.
Yeh, Jennifer, "Arthropoda." The Columbia Encyclopedia, 6th Ed.. 2014,
"Arthropods." UXL Encyclopedia of Science. 2002, Richard Robinson,
"arthropod." A Dictionary of Biology. 2004, Michael Allaby, AILSA
ALLABY;MICHAEL ALLABY, "arthropod." World Encyclopedia. 2005,
"arthropod." The Oxford Pocket Dictionary of Current English. 2009, and
"arthropod." Oxford Dictionary of Rhymes. 2007. "Arthropoda."
Encyclopedia.com. HighBeam Research, 01 Jan. 2002. Web. 03 Oct. 2014.