Invertebrates

1. Invertebrates

2. Characteristics of Animals • All are multicellular eukaryotes • All are heterotrophic • Most are motile, (can move), at least some part of life cycle • Most undergo a period of embryonic development during which 2 or 3 layers of tissues form

3. The Nature of Animals (Kingdom Animalia) • Invertebrates = 95% of all animals • Vertebrate an animal with a backbone (5% of animals) - Vertebrata is a subphylum of the phylum Chordata - Vertebra one of the repeating bony units of the backbone

4. Animal Diversity • Animalia • Invertebrata = (10 major phyla) • Chordata = • (11th major phylum) • * Vertebrata = a subphylum

5. Eleven Major Animal Phyla

6. Symmetry & Body Direction When studying and describing animals, some basic body characteristics are important. These include: Animal Body Symmetry - the way body parts are arranged around a center point. (Asymmetry, Bilateral Symmetry, Radial Symmetry) Directions on the body - used to describe areas on the body of an animal. (Dorsal, Ventral, Anterior, Posterior)

7. Asymmetry = no symmetry

8. Bilateral and Radial Symmetry • Cephalization = concentration of nerve tissue and sensory organs at the anterior end of a bilateral organism

10. Directions on an animal body:

12. Animal Tissue Development Germ tissue layers produce adult organs • Endoderm = develops into gut lining • Mesoderm = develops into muscles and internal body linings • Ectoderm = develops into skin

13. Dorsal Ventral Anterior Posterior Superior Inferior Medial Lateral Distal Proximal Intermediate Superficial deep 9 abdominal regions Frontal Saggital Midsagital Cross section (transverse) Know

14. Acoelomates: The flatworm (planarian) is an acoelomate because it does not have a coelom within its mesoderm layer. Its digesitive cavity is surrounded by the endodermal layer.

15. Pseudocoelomates: Roundworms (Nematoda) and rotifers (Rotifera) have a body cavity (coelom) where organs are found and that can serve as a hydrostatic (fluid-filled) skeleton. Their coelom is called a pseudocoelom because it is not completely lined by mesoderm.

16. Coelomates: with a true coelom

17. Kingdom Phylum Class Order Family Invertebrate Phyla • Sponges • Cnidarians • Platyhelminthes • Nematodes • Mollusks • Annelids • Echinoderms • Arthropods

18. Subkingdom Parazoa ( Porifera) Subkingdom Parazoa ( Porifera) • The unique development and simple anatomy separate this group from other animals • Sponges are the only members • Are hermaphroditic, but usually cross fertilize • Have regeneration abilities for repair and asexual reproduction • Ranked lowest of all multicellular animals • Filter feeders

21. Phylum Cnidaria Phylum Cnidaria • Have tissue-level organization • Are diploblastic ( 2 embryonic germ layers, make up body wall) • Contain hydras, jelly fish, sea anemones and coral

22. Phylum Cnidaria • Characteristics include: • radial symmetry • Have a sac-like body • Gastrovacular cavity present: a central digestive cavity with only one opening ( functions as mouth and anus)

23. 2 Body plans: Polyp: cylindrical form Medusal: free moving Cnidarians are carnivores Phylum Cnidaria

24. 3 Classes of the Phylum Cnidaria • Hydrazoa: have alternating polyp and medusa forms in life, ex hydra and obelia • Scyphozoa: jelly fish • Anthozoa: sea anemones and coral

25. Sea Anenomes

26. Reproduce sexually and asexually by budding The gastrovacular cavity is where extracellular digestion occurs and allows for increase of body size Cnidoblast are armed with stinging hairs called (nematocysts) used for defense and capturing prey hydra hydra

27. Obelia

28. hydra

29. Obelia

30. Gonionemus Gonionemus

31. The world's only immortal animal The turritopsis nutricula species of jellyfish may be the only animal in the world to have truly discovered the fountain of youth.

32. . • Since it is capable of cycling from a mature adult stage to an immature polyp stage and back again, there may be no natural limit to its life span. Scientists say the hydrozoan jellyfish is the only known animal that can repeatedly turn back the hands of time and revert to its polyp state (its first stage of life). • The key lies in a process called transdifferentiation, where one type of cell is transformed into another type of cell

33. . Some animals can undergo limited transdifferentiation and regenerate organs, such as salamanders, which can regrow limbs. • Turritopsi nutricula, on the other hand, can regenerate its entire body over and over again. • Researchers are studying the jellyfish to discover how it is able to reverse its aging process. • Because they are able to bypass death, the number of individuals is spiking. They're now found in oceans around the globe rather than just in their native Caribbean waters.

34. Mrs. Owen's Saltwater Aquarium

35. Candy cane polyps Green Star Polyps

36. Hammer head coral Mushroom polyps Brain coral

37. Anemone

38. Kenya Tree Coral

39. Bubble coral

44. Contains comb jellies ( about 100 species..all marine) Resemble medusa in cnidarians Transparent Possess 8 rows of cilia for locomotion ( called ctenidia..meaning comb bearing) Phylum Ctenophora: Phylum Ctenophora:

45. FLATWORMS Are acoelomates Are the simplest animals with bilateral symmetry All have definite anatomical relationships: anterior, posterior, dorsal, ventral Characteristics Ribbon like soft bodies Bilateral symmetry Contain gastrovascular cavity Phylum Platyhelminthes

46. 3 classes of the Phylum Platyhelminthes • 1. Tubellaria: planarians • 2. Trematoda: flukes • 3. Cestoda: tapeworms • Most members exhibit enough cephalization to have a “head”

47. Tubellaria: planarians

50. Trematoda: flukes