1. Introduction to Animals *Invertebrates*

2. Domain: Eukarya Kingdom: Animalia
All animal cells are eukaryotic which means the all have a nucleus and membrane bound organelles
Animals that cannot make their own food are known as heterotrophs
All animals are made up of many cells or multicellular.

3. Domain: Eukarya Kingdom: Animalia
Animals are classifies by the presence of a backbone, vertebrate, or lacking a backbone, invertebrate.
All animals at some point in their life do move and are called motile.
Some animals that do not move during a stage in their life are called sessile.

4. Breaking up an Animal…
Dorsal
Anterior
Posterior
Ventral

5. Posterior
Dorsal
Ventral
Anterior

6. Symmetry
Animals can be described by their arrangement of body parts, or symmetry.
Asymmetrical - Having parts that fail to correspond to one another in shape, size, or arrangement; lacking symmetry.
Radial - Symmetry around a central axis
Bilateral – Able to be divided into symmetrical halves on either side of a unique plane.

7. Animals are described according to their arrangement of body parts or symmetry.

8. Phylum: Porifera These are the sponges.
They are known mostly for being filter feeders.
No distinct tissues or organs
No Gut
No distinct symmetry
No circulatory system
No nervous system
The “simplest” of animals.

10. Phylum Cnidaria These are hydras, jellyfish and anemones.
Two tissue layers
Radial symmetry
Blind Gut
No circulatory system
Nervous system: network of nerve cells

11. Phylum Cnidaria
Each organism contains tentacles that contain stinging cells known as nematocysts.

12. Hydra

13. Man-o-War

14. Coral

15. Phylum Platyhelminthes
These are the flatworms
Three tissue layers
Bilateral symmetry
Blind gut
No circulatory system
Nervous system: small bundles of nerves (ganglia), two ventral nerve cords

16. Phylum Platyhelminthes
Tapeworms are the most well known flatworms.
Each section of the tapeworm is called a proglottid. It contains both male and female reproduction structures.

17. Phylum Platyhelminthes
You can get a tape worm by eating undercooked meat.

18. Flukes

19. Planaria

20. Phylum Nematoda These are the roundworms. Three tissue layers
Bilateral symmetry
Complete gut
Contains pseudocoel
Circulatory system: present
Nervous system: small bundles of nerves (ganglia), two nerve cords

21. Wuchereria Bancrofti worm that can cause elephantiasis.

23. Hookworm

24. Heartworms

25. Phylum Rotifera These are the wheeled animals.
Complete digestive tract with mouth and anus
Nervous System: small brain from which a number of nerves extend throughout the body with a simple layout.
Rotifers typically possess one or two pairs of short antennae and up to five eyes.
Microscopic
Live in fresh water

26. Rotifers

27. Phylum Mollusca Molluscs are soft bodied.
Some examples are octopus, bivalves, squid, snails, and slugs.
All mollusks except the bivalves have a radula used for tearing their food
Three tissue layers
Bilateral symmetry
Complete gut with anus
Circulatory system: Usually open to large coelomic cavity;
Nervous system: brain, with nerve cords and bundles (ganglia), brain very well developed in squids and relatives

28. Cuttlefish
Octopus

29. Snails

30. Slugs
Clams

31. Phylum Annelida These are the segmented worms.
The 2 big groups are the earthworms and leeches.
Three tissue layers
Bilateral symmetry
Complete gut with anus
Closed circulatory system
Nervous System: brain, with nerve cords and bundles (ganglia)

32. Earthworm
Leeches

33. Phylum Arthropoda This means jointed foot.
These all have segmented bodies and paired appendages. This phylum is HUGE!!!
Three tissue layers
Bilateral symmetry
Complete gut with anus
Segmented
Open circulatory system
Nervous System: brain, with nerve cords and bundles (ganglia),
Has compound eyes

34. Arachnids

35. Crustaceans

36. Centipedes
Millipedes

37. Insects

38. Horseshoe Crabs

39. Phylum Echinodermata This means spiny skin. They move with tube feet.
Three tissue layers
Radial symmetry, sometimes even bilateral symmetry
Blind sac like gut with reduced anus
Circulatory system open
Nervous system: major nerves extending from nerve ring, no brain

40. Starfish

41. Brittle Stars
Sand Dollars

42. Sea Urchins

44. Useful Vocab Coelom – body cavity, where many organs are housed
Pseudocoelom – “false” body cavity; contains no mesodermal cells; organs have no “lining” of these cells.
Deuterostomes -in deuterostomes, the first opening (the blastopore) becomes the anus, while in protostomes it becomes the mouth.
Notochord – supporting rod running the length of the body in chordates (becomes the vertebral column in vertebrates