1. Animal Nutrition III (Ch. 41)

2. Keywords Ruminant digestion Symbiosis –Definition –Algal-invertebrate –Chemoautotroph- invertebrate Hydrothermal vent H 2 S (sulfide) chemoautotrophy

3. mouth Mechanical digestion storage absorption anus Basic parts of alimentary canal

4. Structure of cellulose

5. Cecum Allows breakdown of cellulose in herbivores One opening and exit - lower oxygen, slower passage Digested cellulose must be reintroduced to digestive system

6. Ruminant digestion

7. Ruminant 4 chambered stomach Rumen and reticulum - where symbiotic bacteria and protists break down cellulose Cow rechews food Omasum - where water is absorbed Abomasum - further digestion by cow’s enzymes

9. Symbiosis

10. Autotroph-invertebrate symbiosis Symbionts are algae Algae photosynthesize and provide molecules such as sugars to the host Hydra, anemones, giant clams, corals

11. Examples

16. Chemoautotroph-invertebrate symbiosis Symbionts are chemoautotrophic bacteria Bacteria use hydrogen sulfide as an energy source and provide molecules such as sugars to host Tubeworms, clams, mussels

17. Where do we find these organisms?

18. Life at a vent H2SH2S O2O2

19. Respiratory surface of tubeworm Hb H2SH2S O2O2

20. Oxygen and sulfide are transported to the bacteria

21. Chemoautotrophy: Bacteria oxidize sulfide and use the energy for carbon fixation H2SH2S+ O 2 SO 4 = ADP ATP CO 2 carbohydrate Calvin-Benson Cycle