This document provides an overview of several phyla, including their key characteristics. It discusses Porifera, being suspension feeders that lack true tissue. It also describes Cnidarians, having true tissue, a gastrovascular cavity, and cnidocytes. Finally, it summarizes Platyhelminthes, being bilateral, triploblastic, and including parasitic and free-living classes.

2. • Fw & m
Porifera
• Suspension feeders
• Lack true tissue
• Asymmetrical
• Sequential
hermaphrodites
– (1 then other)
• Produce antibiotics &
other defensive
cmpds
– (Pettit @ AzSU cribostatin – can kill penicillin
resistant strains of Strep & looking for anticancer
cmpds)

3. Cnidarians
• True tissue 4 classes:
• Gastrovascular cavity
(mouth = anus)
• 2 forms: polyp &
medusa
• Cnidocytes
• Nematocysts
(stinging cells)

4. Back to Cnidarians
Hydrozoa
• Most m, few fw
• Polyp & medusa stages
in most sp
• Polyp stage often
colonial

5. Back to Cnidarians
Scyphozoa
• All m
• Polyp reduced
• Free swimming medusa
• Up to 2m in d

6. Back to Cnidarians
Cubozoa
• All m
• Box-shaped medusa
• Highly toxic cnidocytes
– Sea wasp (Chironex
fleckeri) n Australia
• Intense pain
• Respiratory failure
• Cardiac arrest
• Death w/in min
• Amt of poison in 1 org can
kill 60 people

7. Back to Cnidarians
Anthozoa
• All m
• Medusa absent
• Most sessile
• Many colonial

8. Platyhelminthes
• Bilateral symmetry 4 classes:
• Free living &
parasitic
• Microscopic -20m
• Triploblastic
• Acoelomate

9. Back to Platyhelminthes
Turbellaria
• Mostly m, some fw, few
terr
• Predators & scavengers
• Body surface ciliated

10. Back to Platyhelminthes
Monogenea
• M & fw parasites
• Most infect surfaces of
fishes
• Simple life history
• Ciliated larva starts host
infection

11. Back to Platyhelminthes
Trematoda
• Parasites of mainly verts
• 2 suckers attach to host
• Most life cycles include
intermediate hosts

12. Back to Platyhelminthes
Cestoda
• Parasites of verts
• Scolex attaches to
host
• Proglottids prod eggs
and break off after
fert
• No head of digestive
system
• Lc with 1 or more
intmdt host

13. Rotifers
• Specialized organ
systems
• Alimentary canal
(digestive tube w/2
openings)
• Psuedocoelomate
• Parthenogenesis (only
females – make only
females from unfert
eggs)

14. Ectoprocts - bryozoans
Lophophorates
• Lophophore – horseshoe-
shaped or circular crown Phoronids – tube-
dwelling marine worms
of ciliated tentacles that
surround mouth
• Coelomates
Brachiopods – lamp shells – dorsal
/ventral shells instead of bivalve lateral

15. Nermeteans
• Proboscis & ribbon
worms
• Acoelomate
• 1mm-sev m
• Some toxic
• Motly m
• Swim or burrow
• Closed circulatory
system, no heart

16. Molluscs
• Mostly m, some fw, some terr
• Soft bodied
• Most protected by CaCO3 shell, some have
reduced, internal shell or no shell
• Muscular foot, visceral mass, mantle, radula
• Trochophore (ciliated larval stage)
• 4 classes:

17. Chitons
• Polyplacophora
• M
• Shell w/8 plates
• Foot for locomotion
• Radula
• No head

18. Gastropods
• Torsion
• Asymmetrical body
• Foot for locomotion
• Radula

19. Bivalves
• M & fw
• Flattened shell w/2 halves
• Head reduced
• No radula
• Paired gills
• Most suspension feeders
• Mantle forms siphons

20. Cephalopods
• Head surrounded by grasping tentacles
• Locomotion by jet propulsion using siphon
made from foot
• Only mollusc w/ closed circ sys

21. Annelids
• Segmented worms, fw & damp soil
• Length <1mm-3m
• 3groups:
Oligochaeta Polychaeta Hirudinea
Reduced head Well developed head Body flattened
No parapodia Each segment has Reduced coelom and
chaeta parapodia w/chaeta seg
Tube dwelling & free Chaetae ab
living Suckers @ ant & post
ends
Parasites, predators
& scavengers

22. Nematodes
• Roundworms
• most widespread of all animals
• Cuticle – tough outer coat
• Alimentary canal
• No circ sys, nut spread thru fluid in psd-c
• Soil
• Trichinosis

23. Arthropods
• Hard exoskeleton (protein + chitin)
– Molting/ecdysis
• Jointed appendages
• Open circ sys
• 4 groups:

24. Cheliceriformes
• 1-2 main body parts
• 6 prs of appendages
• Mostly terr or m

25. Myriapoda
•Distinct head w/antenna
•Chewing mouth parts
•Terr
Millipedes Centipedes
• Herbivorous • Carnivorous
• 2 prs walking legs/segment • 1 pr walking legs/segment
• Poison claws on first body
segment

26. Hexapoda
• 3 body segments
• Antenna present
• Mouthparts modified
for chewing, sucking
or lapping
• 3 prs of legs
• Us. 2 prs of wings
• Mostly terr

27. Crustacea
• Body 2-3 parts
• Antenna pres
• Chewing mouthparts
• 3+ prs of legs
• Mostly m & fw

28. Deuterostomes
Echinoderms Chordates
• Spiny skin • Doral hollow nerve cord
• Slow moving or sessile • Notochord
• Water vascular sys • Post anal tail
• Tube feet • Pharyngeal slits
• Radial (adult) bilateral
(larvae)
• 6 groups