Objectives: Relate the form of specific structures to their function within this group.

1. Sponges, Cnidarians, Comb Jellies, and Marine Worms Objectives: Relate the form of specific structures to their function within this group. Compare and contrast radial and bilateral symmetry. Apply how the evolution of the segmented body led to increased motility

2. Vocabulary Budding Sexual reproduction Amphiblastula Cnidarians Cnidocytes Polyp Medusa Hydrozoans Arthrozoans Scyphozoans Ctenophora Porifera Asymmetric Radial symmetry Sessile Ostaia Spongocoel Collar cells Choanocytes Pinacocytes Archaeocytes

3. Phylum Porifera: Sponges Sponges are simple asymmetric, sessile (non-moving) animals that lack tissues. Structures found in Sponges: • Ostaia • Spongocoel • Collar cells • Choanocytes • Pinacocytes • Archaeocytes

4. Ostia: tiny holes in the sponge body through which large amounts of water circulate (oxygen and nutrients). Spongocoel: A spacious cavity inside the sponge where water is held and then expelled trough the osculum.

5. Sponge feeding http://www.youtube.com/watch?v=RmPTM965-1c&feature=related

6. Collar Cells: Have a flagellum that moves water through the sponges body and digests nutrients. Pinacocytes: Provides the outer covering of the sponge. Archaeocytes: resemble amoebas, and can move throughout the sponges body. They can form into any of cell types in the sponge body for growth and repair.

7. Reproduction in sponges Sponges can reproduce both asexually and sexually. Budding: a group of cells on the outer surface of the sponge develops and grows into a tiny new sponge. Sexual reproduction: Sponges are hermaphrodites producing both egg and sperm. Amphiblastula: a larval stage that spends time in the water column as plankton before settling and forming a new adult sponge.

8. sponge reproduction

9. Phylum Cnidaria Cnidaria: include, jellyfish, hydrozoans, anthozoans, and corals. All Cnidarians possess Cnidocytes. Cnidocytes are specialized cells used not only to capture prey but also for protection.

10. Cnidarian Body Plan Radial Symmetry: Body is arranged in a circle around a central axis, which can be divided into many planes. Polyp: a benthic (bottom) dwelling Cnidarian characterized by a cylindrical body with an opening at one end (mouth). Medusa: a free-floating stage that is commonly know as a jellyfish.

11. http://www.youtube.com/watch?v=elnpe5u4RZ0

13. Cnidocyte There are more than 2 dozen different types of Cnida (NY-duh) that function for locomotion, defense, and capturing prey. Nematocysts: a spearing type of cnida used to spear prey, that often include a toxin. Example organism: Portuguese man-of-war.

14. Classes of Cnidarians Hydrozoans Arthrozoans Scyphozoans

15. Hydrozoans: • mostly colonial organisms. • Form: Polyps. • Feeding Polyps: • Reproduction Polyps: • Examples: Hydra

16. Anthrozoans:

17. Anthrozoans: Anthrozoans: polyps that secrete a skeleton made of calcium carbonate. Examples: Sea anemones, and corals.

19. Scyphozoans: • Scyphozoans: Jellyfish. Can generally exist in both the polyp stage and medusa stage. Some species have photoreceptors that allow them to determine if it is dark or light.

20. Phylum: Ctenophora Comb jellies Combjellies: Like the Cnidarians, the exhibit radial symmetry. but, they lack Cnidocytes. • some give off flashes of luminescence, possibly to attract mates of frighten predators.