2.1 Invertebrates Porifera, Cnidaria, Platyhelminthes, Annelida.pptx

BRIEF overview of 3 invertebrate phyla

1. Part 2 Invertebrates Phylums -- Porifera, Cnidaria, Platyhelminthes, and Annelida

2. Porifera--Sponges How they reproduce Can reproduce both sexually and asexually (budding) How they get their food Sponges are filter feeders. They eat by straining particles from the water How they move Sponges are sessile , meaning they are unable to move from where they are attached

3. Porifera--Sponges Anatomy Two layers of cells that cover a frame of collagen-like fibers, called spongin, reinforced with hard calcium or silicon- based crystals called spicules Specialized cells: Pinacocytes -outer layer Choanocytes --inner layer of “collar”cells Archaeocytes-- mobile cells between the other layer that absorb/digest food (also called amebocytes in some texts) Fun Fact: Sponges secrete toxic substances to prevent other sponges from growing in their area and protect them from predators/parasites (some of these substances have been used for medicine!)

4. Cnidarians Includes--Corals, Hydras, JELLYFISH , Sea anemones, Sea Pens, Sea Whips, and Sea Fans How they move Wave tentacles to make moves using simple nerve and muscle How they reproduce Can reproduce both sexually and asexually (budding) How they get their food Prey are captured by tentacles and stuffed through the animal’s mouth.

5. Cnidarians Anatomy Two tissues separated by a jelly-like material called mesoglea Outer layer has 3 types of cells Contracting -cover the surface and contain muscle fibers Nerve Cells -send sensory info since they don’t have brains Cnidocytes -contain stinging structures for defense and capturing prey Fun Fact: Most tentacles have nematocysts on the ends (a capsule containing a thin, coiled harpoon-shaped tubule with a venomous barb at the end)

6. Platyhelminthes (Flatworms) Includes Planarians, Flukes, and Tapeworms How they move Muscles along their body help them move, some along slime trails How they reproduce Can reproduce sexually or asexually How they get their food Most absorb nutrients by consuming through mouth into a gut type area that holds, digests, and absorbs into the rest of the body

7. Platyhelminthes-Flatworms Anatomy Flatworms that are unsegmented , bilateral worms Lack a coelem (body cavity that surrounds and protects digestive system and other organs Nervous=head ganglion with nerve cords No respiratory/circulatory systems Fun Fact: Not all, but many, flatworms are parasitic. Some are extremely damaging to humans

8. Annelida (segmented worms) How they move Segments allow muscle contractions so that they can move How they reproduce Most reproduce sexually but some reproduce asexually How they get their food Can range from predators that hunt their food all the way to filter feeders

9. Annelida--Segmented Worms Anatomy Segments contain muscle fibers Internal organs surrounded by coelom (body cavity) Circulatory system is arranged by segments Nervous system contains a ganglia with double nerve cords that run the length of the body Digestive system is a tube with both mouth and anus Fun Fact Some segmented worms have fairly well developed eyes. These worms can be found throughout the world-oceans, freshwater, and land).