1. Invertebrate Diversity
Comparison of Increasing Complexity

2. Remember:
What are the levels of classification?
2. What are the body systems?
3. What organs are in your cranial cavity?
- thoracic cavity?
- abdominal cavity?

3. Kingdom Animalia
Invertebrata Phyla: Porifera -sponges
Cnidaria-sea anemones, coral and jelly fish
Platyhelminthes-planaria, flukes, tapeworms
Nematoda -roundworms

4. Mollusca-snails, seashell animals, octopii and squid
Annelida - earthworms & leeches
Mollusca-snails, seashell animals, octopii and squid
Arthropoda – Insects, Arachnids, Crustaceans,
Echinodermata – Starfish, Sand dollars, sea urchins

5. Porifera Sponges spongin- protein fibers spicules for skeleton
individual cells acting together as an organism
filter water for food
asexual or sexual reproduction (hermaphrodite)

6. Cnideria Jellyfish and corals Radial symmetry
Cnidocytes - stinging barbs to capture prey
polyp to medusa
asexual or sexual

7. Phylum Nematoda
Roundworms
- hydrostatic skeleton
- parasitic worms
                                                                                                                               

8. Phylum Platyhelminthes
Flatworms-tapeworms, Planaria, flukes
- bilateral symmetry
- Ganglia Cells (anterior)

9. Class cestoda Tapeworms Parasites
Attach to intestinal wall of host with scolex
Individual proglottids absorb nutrition from host –don’t need digestive system

10. Mollusca Octopii, Squid, Clams, Snails
Have “cephalization” -a region at the anterior end where well developed sensory organs are located
Open Circulatory system (not real vessels)
Well developed Digestive system
Reproduce sexually
Octopii, Squid,
Clams, Snails

11. E A R T H W O M S
ANNELIDA
& LEECHES

12. External Anatomy
Clitellum - the wider, raised portion of the worm toward the anterior (head) end.
Setae- movement

13. Segmentation
Both Mollusks and Annelids have body plans with distinct regions, but in Annelids, these regions are separated by tissue to form true segments.

14. How are HUMAN BEINGS separated into body segments?
Brain in head
Heart & Lungs in Thorax
Digestive and Reproductive organs below diaphragm

15. Arthropods * largest and most diverse phyla
* segmented bodies, jointed appendages, exoskeleton
* complex muscular system, ventral nerve cord & brain, open circulatory system.
* includes insects, crustaceans, spiders

16. ECHINODERMS * Only live in salt water (oceans)
* They have rays or long, tapering arms.
* Hard, bumpy, spiny skeleton
* Tube feet that aid them in movement, exchanges gases, capture food and excrete waste.
Ex: starfish, sand dollar, sea cucumber, sea urchin