1. Invertebrates

2. Age of Man Age of Mammals Age of Reptiles Age of Inverts
Age of Fishes
Age of Inverts

3. Shapes:
Tiny cups, broad branches, tall vases, encrusting round masses

4. PORIFERA-sponges Most primitive multi-cellular organisms No symmetry
Aggregate of independent cells, lack tissues and organs
Sessile and filter feeding
10,000 species and three classes based on type of spicule

5. Amebocytes
A wandering cell that secretes materials for building a sponge

6. Choanocyte/Collar cells
Cell w/ flagella that creates a water current through the sponges ostia. The sponge obtains its nutrients and oxygen by processing this flowing water

7. Osculum
The large opening through which water exits

8. Ostia (ostium plural)
Water flows thru these tiny pores

9. Pinacocytes
the sponge's outer layer of cells / “skin”

10. Porocytes
cells with pores that allow water into the sponge; they are located all over the sponge's body

11. Spicules
spicules are sharp spikes (made of calcium carbonate) form the "skeleton" of many sponges.

12. Fig. 7.7

13. CNIDARIA
First animals to move-primitive nervous system and muscle tissue
First animals to have a space for digestion
Radial symmetry and stinging tentacles
4 classes: Anthazoa, Hydrazoa, Scyphazoa,
Two body types: polyp and medusa

14. Pleurobrachia
Beroe

15. CTENOPHORA Probably an offshoot of Cnidaria, similar body plan
Biradial symmetry
Ciliary combs and sticky tentacles for catching prey
Known for bioluminescence

16. Bell
free-swimming umbrella-shaped body

17. Ciliary Combs
Cilia on a comb jelly that help them swim

18. Colloblasts
Sticky tentacles of a comb jelly / for catching prey

19. Medusa
a form of cnidarian in which the body is shaped like an umbrella.

20. Polyp
Polyp is the sessile form of the cnidarians with more or less a cylindrical body shape.

21. Nemotocysts
Stinging cell of cnidarians

22. Nerve Net
Simple nervous system in Cnidarians

23. Statocysts
Cells that give a sense of balance/ orientation in the water column

24. Worms on
Bilateral symmetry in all the rest of the invert groups from this point on…
Worms are first groups to develop complete digestive tract, blood vessels, body cavity, headlike area, and a coelom
Most are soft bodied, live in tubes and deposit feed or suspension feed.

26. FLATWORMS Most primitive bilateral animal
Acoelomate- no body cavity /solid body
Trematoda and cestoda classes are parasitic
Turbellaria are carnivorous, many have eyes
Incomplete digestive tract

27. NEMERTEANS Offshoot of flatworm groups
Acoelomate- no body cavity /solid body
Simple circulatory system with blood vessels
Complete digestive tract
Proboscis for catching food- may be poisonous and barbed
Entirely carnivorous and prey on annelid worms and small inverts

28. NEMATODA
Pseudocoelomate- not a true body cavity but a similar fluid filled space
Complete digestive tract
Some of most widespread and numerous multicellular animals
1 m2 of mud can have up to 4,420,000 in it
Covered by scales or cuticle
Free-living and parasitic species

29. Leech
Sabella pavonina
Nereis sp.
Lumbicus terrestris

31. ANNELIDA
Segmented worms- important in increased mobility and evolution of appendages
Largest worms and most differentiated
Coelom
Head-like area
Polychaetes-parapodia on each segment, some with poisonous bristles, gills, eyes and sensory organs on head
Many feeding methods
Hirudinea-leeches: parasitic

33. MOLLUSCS
Second largest invert phylum and fossils back to the Cambrian era
Diversity of form based on an ancestral body plan: bilateral symmetry, head with tentacles, muscular foot for locomotion, shell-excreted by mantle tissue, radula for feeding, open circulatory system in most and coelom
Gastropoda, Bivalvia, Cephalopoda

34. Mollusc Annelid Connection
Similar larvae
Similar segmentation in the Mollusc group monoplacophora

35. ARTHROPODS 80% of all known species
Chitinous exoskeleton-molted for growth
Jointed appendages but tendency towards reduction in number and more specialized in use
Small coelom, open circulatory system, high degree of cephalization, well-developed sense organs and behaviors
Subphylum chelicerata and crustacea

36. en.wikipedia.org
en.wikipedia.org

37. Chelicerata
Body lacks antennae, divided into cephalothorax and opisthoma
5 to 6 pairs of walking arms and book gills
Chelicerae –feeding appendage
Merostomata- horseshoe crabs
scavengers and feed on molluscs, worms and bottom dwelling algae
Pycnogonida-sea spiders
Also have proboscis for feeding
Exclusively bottom dwelling

38. Mollusc-Annelid Connection
Similar embryology
Similar segmentation in a group of molluscs called monoplacophores
Molecular evidence
Arthropod-Annelid Connection
Similar segmentation
Similar appendaging like polychaets
Embryology
Similar organ system arrangement

39. Crustacea 2 pairs of antennae, mandibles, maxillae, and compound eyes
Areas of body are specialized by region and in some cases fused together
Biramous appendages
Great range of diet and even some parasitic examples

41. ECHINODERMS Only major invert group that is a deuterostome.
Entirely marine and largely bottom dwelling
5 part radial symmetry but start life as bilateral larvae
Endoskeleton of calcium carbonate
Water vascular system for locomotion and attachment