1. Animal Evolution – Invertebrates Part II

2. ARTHROPODS meaning “jointed appendages” divided into 4 classes
trilobites

3. Arthropods
Chelicerates
ticks

4. Arthropods
Chelicerates (cont.)
Spiders
Scorpions
Horseshoe crabs

5. ARTHROPODS
Crustaceans
crab
shrimp
crayfish

6. Arthropods
Uniramians
centipedes
millipedes
all insects
grasshoppers

7. Arthropods
Insects (cont.)
bees
moths
flies

8. 3 most important features of an Arthropod
exoskeleton
provides protection and is waterproof
made of chitin
insects
flexible and leathery
lobsters, crayfish
extremely hard

9. Arthropods Jointed appendages used for movement and includes wings
legs
flippers
claws
antennae

10. Arthropods segmented bodies head brain thorax legs abdomen
internal organs
cephalothorax
head and thorax fused
spiders, crayfish and lobsters

11. Arthropods

12. Arthropods respiration gills (crustaceans)
row of feathers located under the exoskeleton

13. Arthropods book gills (horseshoe crab) and book lungs (spider)
layered like pages in a book
increases the surface area for gas exchange

14. Arthropods tracheal tubes (terrestrial arthropods)
spiracles bring air in through tracheal tubes
network of tracheal tubes supplies oxygen to all body tissues by diffusion
works well in small animals only
internal transport
well developed heart pumps blood through an open circulatory system

15. Arthropods blood is pumped from the heart through arteries
once the blood reaches the tissues it is no longer kept in the artery
the blood now bathes the tissues
animal must move its muscles in order to move the blood
blood now collects in spaces called sinuses
the blood collects in a large cavity around the heart and is pumped back through the body

16. Arthropods excretion Anus solid wastes malpighian tubules
dipose of nitrogen wastes
becomes concentrated and is added to the undigested food
green gland
aquatic arthropods
poisonous

17. Arthropods Nervous System well developed brain and ganglion
highly sensitive
picks up
Reproduction
sexual
internal fertilization
spiders and some crustaceans
male deposits sperm packets that female

18. Types of Insect Development
Growth and molting
Types of Insect Development
egg
young
adult
Incomplete metamorphosis
Different stages exploit different resources at different times
egg
nymphs
adult
Complete metamorphosis
egg
larvae
pupa
adult

19. ECHINODERMS meaning “spiny skinned” examples starfish brittle stars
sand dollars

20. Echinoderms
sea urchins
sea cucumber

21. Echinoderms
sea lilies
feather stars

22. Echinoderms Characteristics no posterior or anterior end
primitive nervous system
2 sided
oral surface
mouth (ventral)
aboral surface
top (dorsal)
internal skeleton
larval stages closely related to that of chordates

23. Echinoderms

24. Echinoderms Systems Water Vascular System madreporite
Tube-like structure that opens to the outside
connects to ring canal and hundreds of tube feet
acts like a hydraulic pump
creates a partial vacuum
allows tube feet to grasp onto to objects/prey

26. Echinoderms digestive use tube feet to pry open prey clams, scallops
flips stomach into shell
secretes digestive enzymes
when finished pulls stomach back into its mouth
nocturnal

27. Echinoderms

28. Respiration
use of thin walled tissue found
tube feet
skin gills

29. Echinoderms internal Transport (circulatory)
distribution of nutrients is performed by
digestive glands
fluid within the body cavity
excretion
anus
solid wastes
tube feet and skin gills
excrete ammonia wastes

30. nervous
nerve ring that surround the mouth
radial nerves

31. Echinoderms Reproduction Sexual separate sexes
produce larvae with bilateral symmetry
allow them to swim and feed
settle on the ocean floor and mature into adults that have radial symmetry
Asexual
have the ability to regenerate as long as part of the ring canal is present