Intro to Animals/Fish and Amphibians

1. Intro to Animals/Fish and Amphibians Ch. 24/27-28

2. Chapter 24 Introduction to Animals Section 1: Animal Characteristics Section2: Animal Body Plans Section 3: Sponges and Cnidarians

3. Introduction to Animals Chapter 24 24.1 Animal Characteristics General Animal Features • The ancestral animals at the beginning of the evolutionary tree are eukaryotic and multicellular. • They developed adaptations in structure that enabled them to function in numerous habitats.

4. 24.1 Animal Characteristics • Invertebrates- (Exoskeletons) Hard or tough outer coverings that provide a framework of support • Protect soft body tissues, Provide protection from predators

5. 24.1 Animal Characteristics • Vertebrates- (Endoskeletons) Protect internal organs, Provide support for the body • Provide an internal brace for muscles to pull against • Movement: The evolution of nerve and muscle tissues enables animals to move in ways that are more complex and faster than organisms in other kingdoms.

6. 24.1 Animal Characteristics • Fertilization occurs when the sperm penetrates the egg to form a fertilized egg cell called the zygote. • Internal fertilization- the egg and sperm unite inside the animals body ….humans • External fertilization- the egg and sperm unite outside the animals body ….fish

7. 24.1 Animal Characteristics • What are the first few phases of early development in most animals. Please provide a visual for full credit. • The zygote undergoes mitosis and a series of cell divisions to form new cells.

8. 24.1 Animal Characteristics • The cells continue to divide, forming a fluid-filled ball of cells called the blastula. • The blastula continues to undergo cell division as some cells move inward to form a gastrula.

9. Introduction to Animals Chapter 24

10. Introduction to Animals Chapter 24 24.1 Animal Characteristics Tissue Development • Endoderm • inner layer of cells in the gastrula • Ectoderm • outer layer of cells in the gastrula • Mesoderm • layer of cells between the endoderm and ectoderm

11. Introduction to Animals Chapter 24 24.1 Animal Characteristics

12. Introduction to Animals Chapter 24 24.2 Animal Body Plans Evolution of Animal Body Plans • Anatomical features in animals’ body plans mark the branching points on the evolutionary tree. • Relationships on this tree are inferred by studying similarities in embryological development and shared anatomical features.

13. Introduction to Animals Chapter 24 24.2 Animal Body Plans Symmetry • Similarity or balance among body structures of organisms • Asymmetry • Radial symmetry • Bilateral symmetry

14. Introduction to Animals • Have a fluid-filled cavity with tissue formed from mesoderm that lines and encloses the organs in the coelom Chapter 24 24.2 Animal Body Plans Body Cavities • Coelomates

15. Introduction to Animals • Have a fluid-filled body cavity that develops between the mesoderm and the endoderm rather than developing entirely within the mesoderm Chapter 24 24.2 Animal Body Plans Body Cavities • Pseudocoelomates

16. Introduction to Animals Chapter 24 24.2 Animal Body Plans Body Cavities • Acoelomates • Have solid bodies without a fluid-filled body cavity between the gut and the body wall

17. Introduction to Animals Chapter 24 24.2 Animal Body Plans Development in Coelomate Animals • Protostomes • The mouth develops from the first opening in the gastrula. • Deuterostomes • The anus develops from the first opening in the gastrula.

18. Introduction to Animals Chapter 24 24.2 Animal Body Plans Segmentation • Segmented animals can be “put together” from a succession of similar parts. • Can survive damage to one segment • Movement is more effective

19. Introduction to Animals Chapter 24 24.2 Animal Body Plans

20. Chapter 28 Fishes and Amphibians Section 1: Fishes Section2: Diversity of Today’s Fishes Section 3: Amphibians

21. Chapter 28 Fishes and Amphibians • Vertebrates have a vertebral column and specialized cells that develop from the nerve cord. • The vertebral column, or spinal column, is the hallmark feature of vertebrates. • A vertebral column can start as a notochord made of cartilage that protects the dorsal nerve cord then develop into bone.

22. Lamprey dissection

24. Diversity of Today’s Fishes • Scientists have grouped fishes into three classes based on their body structure. Jawless Fishes (support system is cartilage) • Hagfish feed on soft-bodied invertebrates and dead or dying fish on the sea floor. • Lampreys are parasites that feed by attaching themselves to other fishes. Agnatha

25. Cartilaginous Fishes • All cartilaginous fishes have skeletons made of cartilage. • The flexible skeleton, rows of sharp teeth, a streamlined body, and placoid scales make sharks one of the top predators in the sea. • Skates and rays have flattened bodies that are adapted for living on the ocean floor.

26. Bony Fishes • There are two groups of bony fishes: the ray-finned fishes and the lobe-finned fishes. • Thin, spinelike rays support the fins of ray-finned fishes. • Lobe-finned fishes have muscular lobes and joints similar to those of land vertebrates.

27. Fishes and Amphibians Chapter 28 28.2 Diversity of Today’s Fishes Evolution of Fishes

28. Fishes • Jaws: Anterior gill arches evolved into jaws in ancient fishes. • The development of jaws allowed ancient fishes to prey on a larger range of animals.

29. Fishes • Paired Fins: A fin is a paddle-shaped structure on a fish or other aquatic animal that is used for balance, steering, and propulsion. • Paired fins reduce the chance of rolling to the side and allow for better steering during swimming.

30. Fishes and Amphibians Chapter 28 28.1 Fishes Scales • There are four types of fish scales. • Ctenoid scales • Placoid scales • Ganoid scales • Cycloid scales

31. Fishes • Gills: Fishes get oxygen when water that enters their mouths flows across their gills, where oxygen from the water diffuses into the blood. (Pressure: Volume relationship!!) • Gills are composed of thin filaments that are covered with highly-folded, plate-like lamellae.

32. Fishes and Amphibians Chapter 28 28.1 Fishes Circulation • Vertebrates have a closed circulatory system. • In most fishes, the heart consists of two main chambers—the atrium and the ventricle.

33. Fishes and Amphibians Chapter 28

34. Fishes and Amphibians Chapter 28 28.1 Fishes Feeding and Digestion • Most fishes swallow their food whole, passing it through a tube called the esophagus to the stomach, where digestion begins.

35. Fishes • Explain the importance of the lateral line and the swim bladder. How does each work?

36. Fishes and Amphibians Chapter 28 28.1 Fishes The Brain and Senses • Color vision, chemical detection, hearing, and balance are coordinating in the brain. • The lateral line system is a special sensor that allows fish to detect even the slightest movements in water.

37. Fishes and Amphibians Chapter 28 28.1 Fishes Reproduction • The majority of fishes reproduce through external fertilization. • Male and female fishes release their gametes near each other in the water in a process called spawning.

38. Fishes and Amphibians Chapter 28 28.1 Fishes Movement • Fishes are well adapted to swimming in the water. • Streamlined shape • Paired fins • Swim bladder • Fishes move through the water by contracting muscle groups on either side of their bodies.

39. Lamprey and Perch • What are the four differences between the lamprey and the perch.

40. Fishes and Amphibians Chapter 28 28.3 Amphibians:

41. Fishes and Amphibians Chapter 28 28.3 Amphibians Characteristics of Amphibians • Most amphibians begin life as aquatic organisms. Tadpole • After metamorphosis, they are equipped to live life on land. Frog

42. Fishes and Amphibians Chapter 28 28.3 Amphibians Feeding and Digestion • Most frog larvae are herbivores, whereas salamander larvae are carnivores. • As adults, their diets are similar as both groups become predators. Intestines must shorten. • The digestive system of an amphibian is very similar to that of a fish.

43. Fishes and Amphibians Chapter 28 28.3 Amphibians Respiration • As larvae, most amphibians exchange gases through their skin and gills. • As adults, most breathe through lungs, their thin, moist skin, and cavities in the mouth.

44. Fishes and Amphibians Chapter 28

45. Fishes and Amphibians Chapter 28 28.3 Amphibians Circulation • Amphibians have a double-loop circulatory system. • Amphibians have three-chambered hearts.

46. Fishes and Amphibians Chapter 28

47. Fishes and Amphibians Chapter 28 28.3 Amphibians Reproduction and Development • In most amphibians, fertilization is external and the shell-less eggs must be laid and fertilized in water. • Tadpoles hatch from the egg and undergo metamorphosis from a fishlike animal to an air-breathing one.

48. Fishes and Amphibians Chapter 28 28.3 Amphibians Amphibian Diversity • Scientists classify modern amphibians into three orders. • Order Anura includes frogs and toads. • Order Caudata includes salamanders and newts. • Order Gymnophiona includes caecilians. Legless and wormlike!! Page 839.

49. Fishes and Amphibians Chapter 28 28.3 Amphibians Evolution of Amphibians