1. Introduction to the Animal Kingdom & Sponges Chapter 26

2. Animal Kingdom Characteristics Basic functions: feeding, respiring, circulating, excreting, responding, moving, and reproducing Heterotrophic cells No cell walls Multicellular Eukaryotic Asymmetry or symmetry Invertebrate or vertebrate

3. Animal development Zygote: fertilized egg (2n) Blastula: hollow ball of cells that folds on itself at the blastopore opening Tube from blastopore is the digestive tract that can form the mouth (protostome) or the anus (deuterostome) from the opening.

4. Embryonic tissues Endoderm: inner layer  digestive tract and respiratory system Mesoderm: middle layer  muscles, circulatory, reproductive and excretory organs Ectoderm: outermost layer  sense organs, nerves, and epidermis

5. Body cavity Space where internal organs are housed coelomates, pseudocoelomates or acoelomates, depends how cavity is made

6. Body symmetry Asymmetrical: no plane dividing body into equal halves Radial symmetry: multiple planes dividing body into equal halves Bilateral symmetry: one plane dividing body into equal halves

7. Section 26-1 Radial Symmetry Bilateral Symmetry Planes of symmetry Plane of symmetry Ventral side Dorsal side Posterior end Anterior end Body Symmetry Figure 26–5

8. Cephalization Concentration of sense organs and nerves Usually associated with head region Defines the difference between head and tail regions head tail

9. Introduction to Invertebrates Click on image to play video.

10. Invertebrates video 2 Click on image to play video.

11. Sponges: the simplest animals

12. Sponge characteristics Invertebrate Multicellular Heterotrophic No cell walls Asymmetrical Few specialized cells

13. Section 26-2 Water flow Choanocyte Spicule Pore cell Pore Epidermal cell Archaeocyte Osculum Central cavity Pores The Anatomy of a Sponge Figure 26–8

14. Choanocyte Collar cells that line cavity Obtains nutrients and oxygen from flowing water when flagella beat

15. Spicule Spicule; spike-shaped structure made by archaeocytes that move around in the sponge walls

16. Archaeocytes processes food distributes nutrition to other cells

17. Porocyte porous cells where water can flow into sponge cavity

18. Boat that is harvesting sponges Spongin: flexible protein found in soft sponges

19. Feeding Filter feeders: sift food from water current Intracellular digestion Choanocytes trap food that are then passed onto the archaeocytes. Waste flows out of the large opening.

20. Respiration, Circulation, & Excretion Rely on water movement through the body for gas exchange, nutrient and waste transport/elimination

21. Response No nervous systems to respond to environmental changes Produce toxins that make them unpalatable or poisonous To treat irritations from this sponge, apply a vinegar-soaked cloth for 15 minutes. Use a piece of adhesive tape on the wound to remove any spicules.

22. Reproduction Sexual: –Internal fertilization –Sperm released, egg maintained Asexual –Budding –Gemmules: groups of archaeocytes surrounded by spicules (much like spores)

23. Sponge habitat photo by Justin Gilligan