1. Coelomate Animals Have a true coelom, not a pseudocoelom
True coelom is a hollowed out space inside the mesoderm, not a space between tissue layers
Coelom provides space for organs to develop

2. 2 Groups of Animals have Coeloms
Protostomes
mouth forms first
Phylum Mollusca
Phylum Annelida
Phylum Arthropoda
Deuterostomes
anus forms first
Phylum Echinodermata
Phylum Chordata

4. New Traits of All Coelomates
Circulatory systems that pump blood
Excretory systems = kidney or gland or tubules
Respiratory structures present in most species
Gills in: - some Mollusks
Some Arthropods (Crustaceans)
Some Chordates (lamprey, Fish, larval Amphibians)
Lungs in: - some Mollusks
Lung fish
Some Chordates (adult Amphibians, Reptiles, Birds, Mammals)
Trachea in: Insects
Book lungs in: Arachnids

5. Phylum Mollusca = mollusks
All have Alimentary canals
Respiration by gills, lung or by diffusion
All have hearts & open circulatory systems
Blood leaves heart in blood vessels called arteries
Blood flows out the open ends of the arteries to circulate directly through tissues and sinuses
Blood funneled back to heart to be pumped again

6. Specialized Mollusk Traits
Mantle = membrane covering that may secrete a shell
Radula = feeding structure that may be like a file, a drill or a beak
Muscular Foot = used for locomotion

7. Class Bivalvia Name means 2 shells Most are filter feeders
Clams, oysters, mussels, scalops

8. Class Gastropoda Name means Stomach-Foot
snails, slugs & nudibranchs (sea slugs)

9. Class Cephalopoda Name means head-foot
Squids, octopuses, nautiluses, cuttlefish

10. Giant Squid! Largest invertebrate Up to 60 ft long
This one was a young female 24 ft long
The first live giant squid ever captured
Large size made possible by myalinated nerves and closed circulatory system

11. Cephalopod Derived Traits : Adaptations of a Predator
Shell filled with chambers of air for buoyancy
Shells lost or small & internal = less weight
Closed circulatory system = faster circulation for better delivery of oxygen to muscles
Well developed eyes and brain = must be smarter than the food
Foot converted to tentacles
and siphon (jet propulsion)

12. Phylum Annelida:Segmented worms
Earth worms
Leeches
Marine Worms
Freshwater
worms

13. Annelid traits Body divided into segments
Respiration by diffusion or gills
Excretion by true nephridia in each segment
Alimentary canal
Closed circulatory system (blood always in vessels or heart)
Ganglia with ventral nerve cords

14. Phylum Arthropoda Subphylum Crustacea Class Insecta Class Arachnida
Classes Diplopoda/chilopoda

15. Arthropod Traits Name means jointed-foot Also have jointed legs
Segmented bodies
Exoskeleton
Open circulatory system
Ganglia fused into simple brain
ventral nerve cords
Complete digestive system

16. Insect Innovations
Respiration using tracheae –tubes that branch throughout the body
Compound eye
Wings
Complex life cycle

17. Arachnids Respiration by book lungs spiders ticks mites Scorpions
harvestmen
May have silk glands to make web

18. Crustacea Nearly all aquatic Respiration by gills
Important part of zooplankton