Animals

1. Animals Invertebrates

2. Kingdom Animalia • Around 9 or 10 million species of animals inhabit the earth • About 800,000 species have been identified

4. Traits WHAT IS AN ANIMAL ? ? ?

5. General Traits of Animals • A multicellular eukaryotic heterotroph • Contain specialized cells  division of labor

6. Lions Feeding (HETEROTROPHIC)

7. Characteristics of Animal Life • 1. Living things are organized • 2. Living things are made up of cells • 3. Living things metabolize • 4. Living things grow • 5. Living things respond • 6. Living things reproduce • 7. Living things evolve • 8. Animals rely on other organisms for their nourishment

8. Support Systems • Have some type of skeletal/fluid structural support • Endoskeletoninside and made of cartilage &/or bone • Exoskeletons found in arthropods • Cover the outside of the body • Must be molted making animal vulnerable to predators

9. Cicada Molting Exoskeleton

10. Support Systems • Worms and echinoderms (starfish) have fluid-filled internal cavities giving them support • Called hydrostatic skeletons

11. Most Animals Exhibit Movement • Animals such as sponges may be sessile (attached & non-moving) • Animals that move very little are said to be sedentary (clam) • Animals that can move are motile. • Have muscular tissue to provide energy for movement

12. SESSILE SEDENTARY Chiton Sponge MOTILE Cheetah

13. Reproduction in Animals • Pretty much all animals are capable of sexual reproduction • Some animals like sponges and earthworms are hermaphroditesproducing both eggs and sperm • Hermaphrodites may exchange sperm and NOT fertilize their own eggs

14. Leeches Exchange Sperm During Sexual Reproduction leech Mating

15. Molecule or compound Atom Organelle Levels of Organization CELL Life begins Tissue Organ Organ system Organism

16. Levels of Organization

17. Levels of Organization • Sponges are the ONLY animals that have just the cellular level of organization • All other animals show these levels – cell  tissue  organ  system • Cells may specialize(take on different shapes and functions) • Cells are held together by cell junctions to form tissues • Various tissues can build organs

18. Trends in Animal Evolution • Increase level of organization (cell  tissue  organ) • Change in symmetry (asymmetrical radial  bilateral) • Increase concentration of sense organs and nerve cells in the animal’s anterior region (cephalization)

19. Body Symmetry

20. Symmetry

21. Animal Symmetry • Primitive animals are asymmetrical • Cnidarians and echinoderms have radial symmetry • Most animals have bilateral symmetry

22. Body Symmetry • Symmetry • Asymmetry

23. Radial Symmetry Radial Symmetry applies to forms that can be divided into similar halves by more than two planes passing through it. Animals with radial symmetry are usually sessile, free-floating, or weakly swimming.

25. Bilateral Symmetry • This is a shape that is two sided and produces a mirror image affect. • Animals with bilateral symmetry usually has led to cephalization.

27. Anatomical Direction • Ventral - the underside • Dorsal - the back of the animal; the side opposite the ventral side. The vertebral column of vertebrates is on the dorsal side of the animal. • Anterior - the head end • Posterior - the end opposite the head end • longitudinal plane - along a line from the head to the tail • Transverse plane - along a line that is 90° to the longitudinal axis (see above)

28. Surfaces (Most Animals) DORSAL POSTERIOR ANTERIOR VENTRAL

30. Classification of Invertebrates

31. Phylum Porifera Sponges Origins

33. General Characteristics • Literally means “pore-bearers” • Asymmetrical or Radial symmetry • Among the most ancient of all animals alive today • Most are saltwater sponges • Inhabit almost all areas of sea (eg. polar and tropic regions, low-tide and deep water) • Adult sponges are sessile • Multicellular animals • Heterotropic • No mouth, gut, specialized tissues or organ systems. Therefore, most biologists believe that sponges evolved from singe-celled ancestors separately from other multicellular animals.

34. Sponge Structure Water flows through the pores into the central cavity and out of the osculum. Collar cells draw out the food from the water as it flows through the pores.

35. Sponge’s Skeleton Sponges are composed of spicules and/or spongin to support their structure. The amebocytes are responsible for producing the (CaCO3 or SiO2) spicules and spongin (protein)

36. Form • Body of sponge forms a wall around a hollow central cavity. • Body wall has openings or pores through which a steady current of water moves through and enters the central cavity. • Current of water powered by the flagella of cells called collar cells • The current of water delivers food and oxygen to the cells and carries cellular waste products into the central cavity and out an opening at the top of the sponge known as the osculum. • Gametes or larvae are also transported through the water. • Spiny spicules interlock to form the skeleton of the sponge. • Amebocytes produce spicules from either calcium carbonate or silica. • Softer but stronger sponges have skeletons that consist of fibers of a protein called spongin • Some sponges have skeletons made of both spongin and spicules.

37. Collar Cell Sponges are filter feeders that feed on microscopic particles of food. Food is drawn into the collar, become trapped and then engulfed by the cell (endocytosis) and enters a food vacuole.

38. Digestion • Are filter feeders • Food particles stick to collar cells, which engulf (endocytosis) and digest the particles. • Amebocytes digest food particles that collar cells do not digest. They then deliver digested food to other parts of the sponge. • All digestion is intracellular. Filter feeding made visible

39. Exception to filter feeding

40. Respiration, Excretion, Internal Transport System As water passes through the body wall, sponge cells obtain oxygen and release carbon dioxide. Metabolic wastes (eg. ammonia) are also released.

41. Reproduction - Asexual • Gemmules are produced at the onset of winter. They are highly resistant to both freezing and drying • Budding – whenprotrusions arise on the parent’s surface and breaks off to form a new sponge (exact copy of parent) Regeneration

42. Reproduction Sexual Eggs are kept inside the wall of the sponge, while sperm are released into the water flowing through the sponge and carried into the open water. Sperm flow into other sponges and are picked up by amebocytes to be carried to where the eggs are stored and fertilization occurs here. Zygote develops into larva and swims out of the osculum.

43. Reproduction • Both asexual and sexual • Asexual • Gemmules are produced at the onset of winter. They are highly resistant to both freezing and drying • Budding - whenprotrusions arise on the parent’s surface and breaks off to form a new sponge • Sexual (Figure 26-12) • Gametes (egg and sperm) are produced in the body wall • sperm is released into the open water and enters a sponge wall via amebocytes • fertilization occurs inside the body wall • larvae swims out into the open water and eventually settles down to become sessile

45. Ecological Importance • Many marine animals, such as worms, shrimp, snails and starfish live on, in and under sponges. • Symbiotic relationships with blue-green bacteria, bacteria, or plantlike protists. • Sponges important part of the diets of certain snails, starfish and fishes. • Boring sponges help clean up the ocean floor. • Used by humans in bathing. • Sponges produce numerous compounds toxic to organisms. Many of these chemicals are powerful antibiotics used to fight disease causing bacteria, viruses and fungi.

46. Wild Ride through Sponges