1. Introduction to animals Introduction to Animals

2. Characteristics of Animals All multicellular Eukaryotes Heterotrophs (take in food and internally digest it) Store food reserves in the liver as glycogen

3. Support Systems Have some type of skeletal support Endoskeleton inside and made of cartilage &/or bone Exoskeletons found in arthropods –Cover the outside of the body –Limit size –Must be molted making animal vulnerable to predators

4. Cicada Molting Exoskeleton

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

6. 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

7. SESSILESEDENTARY MOTILE Sponge Chiton Cheetah

8. Reproduction in Animals All animals are capable of sexual reproduction Some animals like sponges and earthworms are hermaphrodites producing both eggs and sperm Hermaphrodites may exchange sperm and NOT fertilize their own eggs

9. Leeches Exchange Sperm During Mating Mating leech

10. Reproduction in Animals Females of some animals produce eggs, but the eggs develop without being fertilized Called Parthenogenesis New offspring will be all female Parthenogenesis occurs in some fishes, several kinds of insects, and a few species of frogs and lizards

11. Parthenogenesis in the Komodo Dragon

12. Mating and Mating Behaviors Beetles Mating Male Female Young Courtship

13. Levels of Organization Sponges are the ONLY animals that have just the cellular level All other animals show these levels – cell, tissue, organ, and system Cells may specialize (take own different shapes and functions) Cells are held together by cell junctions to form tissues

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

15. Invertebrate groups

16. Characteristics of Invertebrates Simplest animals Contain the greatest number of different species Most are aquatic (found in water) Do NOT have a backbone Includes sponges, cnidarians, flatworms, roundworms, annelids, mollusks, arthropods, and echinoderms

17. 1. Phylum Porifera (Sponges)

18. Sponge - Porifera Osculum of Sponge

19. Phylum Porifera (Sponges) (exit for water) (digest and distribute food) (skeleton) Choanaocyte *** Sponges are Parazoans: they contain NO true tissues *** Sponges are filter feeders

20. 2. Phylum Cnidaria Jellyfish, Corals, and other Stingers

21. General Characteristics Simple body plan-bag shaped organism Radially symmetrical organization Consists of a mouth and a sac-like cavity Lacks an anus The mouth is surrounded by a ring of tentacles The cavity in the center of the gut, called the gastrovascular cavity.

22. Two Body Forms Polyps - attached to a surface - ex: sea anemones - mouth points up Medusae - free floating -ex: jellyfish -mouth points down

23. Sea Anemone - Cnidaria Tentacles of Sea Anemone

24. More Cnidarians Brain Coral Red jellyfish

25. 3. Phylum Platyhelminthes (Flatworms) Platyhelminthes consists of three kinds of acoelomate flatworms. 1. Free-living Flatworms: such as planarians, which are carnivorous scavengers. 2. Flukes: are internal, or external, parasites that suck tissue fluids or blood. 3. Tapeworms: internal parasites that live in the intestinal tracts of vertebrates.

26. Flatworms - Platyhelminthes Planarian Marine Flatworm

27. Planaria

28. Tapeworm Scolex (head) Young Proglottids Old Proglottids ** tapeworms appear to be segmented, but they are not true “segmented” worms

29. 4. Phylum Nematoda (Roundworms) Found in fresh water, marine, moist soil, tissues of plants, and tissues and body fluids of animals A complete digestive tract is present and nutrients are transported through the body in the pseudocoelomic fluid. Free-living forms are important in decomposition Animal parasitic forms can be hazardous to health.

30. (Trichinella spiralis in humans via undercooked infected pork)

31. Nematode

33. 7. Phylum Annelid (Segmented Worms: includes leeches, earthworms and polychaetes) Leeches are freshwater but some are terrestrial in moist vegetation. Many are carnivorous and feed on small invertebrates, while some attach temporarily to animals to feed on blood. They have 2 suckers, one at each end.

34. leech

35. Earthworms ingest soil, extract nutrients in the digestive system and deposit undigested material (mixed with mucus from the digestive tract) as casts through the anus. Important to farmers as they till the soil and castings improve soil texture

37. Polychaetae drift and swim in the plankton, some crawl along the sea floor, and many live in tubes they construct by mixing sand and shell bits with mucus. Tube-dwellers include the fanworms that feed by trapping suspended food particles in their feathery filters which are extended from the tubes.

38. Phylum Annelid Fanworm Polychaete Worm

39. 6. Phylum Mollusca (snails, bivalves, octopuses and squids) In Squids, the shell is reduced and is internal. In octopuses, the shell is entirely absent. Octopuses have a highly developed nervous system with a large, complex brain.

40. Snails

41. Mollusca (With and Without Shells) snailscallop nautilus nudibranch octopus

42. 8. Phylum Arthropoda (spiders, insects, crustaceans, and various related organisms) Arthropods have two kinds of life cycles…(1) complete metamorphosis, (2) incomplete metamorphosis. Arthropods have: * jointed appendages, * a well-developed nervous system, * specialized body segments, and * an exoskeleton made of chiton.

43. The specialized body segments are the: Head, Thorax and Abdomen

44. Incomplete Metamorphosis (immature forms are often called nymphs) Nymphs resemble the adult in form except for being smaller and lacking fully developed wings and sexual organs. Life Cycle: Egg nymph adult

45. Complete metamorphosis Immature forms are called larvae (larva, singular). The pupal stage is a transition stage, when the larva is transformed to the adult. Pupa molts to the adult form. Life Cycle: Egg --> larva --> pupa --> adult

46. Arthropoda (insects, spiders, crustaceans, horseshoe crab) Dung beetle Horseshoe crab crayfish spider

47. 9. Phylum Echinodermata (sea stars (starfish), sea urchins and sand dollars) Echinoderms are Coelomates Deuterostomes Echinoderms have complete digestive systems Although some adults exhibit radial symmetry, some features are bilateral, as are the body shapes of their larvae.

48. Echinoderms Sea cucumber Sand dollar starfish Brittle star Sea fan (crinoid)

50. Vertebrate Groups

51. 10. Phylum Chordata The Phylum Chordata consists of animals that exhibit the following four features. In many cases, these features are temporary, appearing only during embryonic development.

52. 1. A Notochord A notochord provides support for the body. It is a flexible cord located on the dorsal surface. In most cases, the notochord is replaced by bone during development. Notochord

53. 2. A Dorsal Hollow Nerve Cord A dorsal hollow nerve cord forms the basis of the nervous system. In some chordates, the nerve cord becomes the brain and spinal cord.

54. 3. Pharyngeal Gill Slits Pharyngeal Gill Slits provides channels across the pharynx to the outside of the body. In some chordates, the slits become gills for oxygen exchange, or for filter feeding, while in others, the slits disappear during embryonic development.

55. 4. A Muscular Tail A muscular tail extends beyond the digestive system. In many chordates, such as humans, the tail is lost during embryonic development.

56. There are Two Groups of Chordates 1. Invertebrate Chordates: includes lancelets and tunicates. 2. Vertebrate Chordates: includes sharks, fish, amphibians, reptiles, birds and mammals. Vertebrate Chordates are characteristics by a series of bones, the vertebrae, that enclose the spinal cord.

57. Vertebrata More complex animals Most have a backbone made up of individual bones called vertebrae From simplest to most complex, the phylum includes: fish, amphibians, reptiles, birds, and mammals

58. Vertebrate Backbone

59. Vertebrata Vertebrates have endoskeletons (internal) Some vertebrates have skeletons of cartilage (sharks, rays, and skates) Other vertebrates have skeletons of bone and cartilage (reptiles, birds, & mammals)

60. Bone & Cartilage in Fetus

61. Fish lancelet ray anglerfish damselfish

62. Amphibia toad newt frog salamander

63. Reptilia Turtle Snake Alligator Lizard

64. Birds - Aves hummingbird ostrich lovebirds

65. Mammalia

66. Body Areas

67. Surfaces Dorsal – back or upper surface Ventral – belly or lower surface Anterior – head or front end Posterior – tail or hind end opposite the head Oral surface (echinoderms) – is where the mouth is located (underside) Aboral surface (echinoderms) – is opposite the mouth (top side)

68. DORSAL VENTRAL Surfaces (Most Animals) ANTERIOR POSTERIOR

69. Surfaces (Echinoderms) ORAL ABORAL mouth

70. Symmetry

71. Body Symmetry

72. Symmetry is the arrangement of body parts around a central plane or axis Asymmetry occurs when the body can’t be divided into similar sections (sponges)

73. Body Symmetry Radial symmetry occurs when body parts are arranged around a central point like spokes on a wheel (echinoderms) Most animals with radial symmetry are sessile (attached) or sedentary (move very little)

75. Body Symmetry Bilateral symmetry occurs when animals can be divided into equal halves along a single plane Organisms will have right and left sides that are mirror images of each other More complex type of symmetry

76. Body Symmetry Animals with bilateral symmetry are usually motile Animals have an anterior and posterior ends Show cephalization (concentration of sensory organs on the head or anterior end)

78. Segmentation

79. Segmentation Occurs whenever animal bodies are divided into repeating units or segments Found in more complex animals Earthworms show external segmentation Humans show internal segmentation (backbone) Segments may fuse (cephalothorax)

80. Segmentation cephalothorax

81. Tissues

82. Tissue Development Zygote (fertilized egg) undergoes rapid cell divisions called cleavage Forms a hollow ball of cells called the blastula

83. Blastula The blastocoel is the center cavity of the blastula with 1 germ layer (blastoderm)

84. Tissue Development The blastula INVAGINATES (folds inward at one point) Called Gastrulation The opening is called the blastopore The center is the primitive gut or Archenteron blastopore Archenteron

85. Tissue Development Blastopore may become the mouth (Protostome) or anus (Deuterostome) Protostomes (mollusks, arthropods, & annelids) Deuterostomes (echinoderms & vertebrates) Some animals form a middle germ layer called mesoderm

86. Embryonic Development

87. Germ Layers Form tissues, organs, & systems NOT present in sponges Ectoderm (outer) – forms skin, nerves, sense organs Endoderm (inner) – forms liver and lungs Mesoderm (middle) – forms muscles & other systems

88. Body Layers Sponges have NO tissues or organs, only specialized cells Cnidarians like jellyfish & coral have only two body layers & one body opening (mouth/anus) into gastrovascular cavity Cnidarians have outer epidermis & inner gastrodermis with jelly- like mesoglea between the layers

90. Body Layers All worms, mollusks, arthropods, echinoderms, and vertebrates have three cell layers –Ectoderm –Endoderm –mesoderm

91. Embryonic Cleavage

92. Cleavage Cleavage – rapid mitosis (cell division) of zygote Radial Cleavage – cells divide parallel or perpendicular to axis to each other

93. Cleavage Spiral Cleavage – cellular divisions occur diagonally, in a twisting pattern

95. Stages of Development

96. Larval Forms Animals with Indirect development Go through immature (larval) forms Larva does NOT resemble adult Cnidarian (jellyfish, coral, & sea anemone) larva called Planula

97. Larval Forms Mollusk (squid & octopus) larva called trochophore Echinoderm (starfish) larva is called Dipleurula

98. Metamorphosis Usually found in arthropods May be complete or incomplete Incomplete Metamorphosis: egg nymph adult Complete Metamorphosis: egg larva pupa adult

99. Metamorphosis COMPLETE INCOMPLETE

100. Body Cavities

101. Coelom - Body Cavity Internal body cavity fully lined with mesoderm Body organs suspended in this cavity

102. Coelom - Body Cavity Acoelomate animals have solid bodies filled with cells Acoelomate animals include sponges, cnidarians, & flatworms

103. Coelom - Body Cavity Pseudocoelomate animals (roundworms) have a functional body cavity NOT fully lined with mesoderm

104. Animal Systems

105. Support Systems Spongin & spicules (sponges) Limestone cases (corals) Exoskeletons of Chitin (arthropods) –Must be shed or molted to grow Inner Calcium plates or Test (echinoderms) Bone/cartilage endoskeleton (vertebrates)

106. Digestive Systems All animals are ingestive heterotrophs Choanocytes (specialized cells) capture & digest food for sponges Gastrovascular cavity with one opening in cnidarians and flatworms for food to enter & leave; called two-way digestive system

107. Two-Way Digestion

108. Digestive Systems Animals with a one-way digestive system have a mouth and an anus Food enters the mouth, continues in one direction through the digestive tract, and wastes leave through the anus Includes annelids, arthropods, & vertebrates

109. One-Way Digestion Mouth anus

110. Circulatory Systems Transports oxygen & nutrients to cells Carries away wastes & carbon dioxide from cells Sponges, cnidarians, & flatworms do NOT have circulatory systems

111. Circulatory Systems In closed circulation, blood remains inside blood vessels until it reaches cells (annelids & vertebrates) In open circulation, blood is pumped out of blood vessels to bathe tissues in the body cavity or hemocoel (arthropods & mollusks)

112. Open Circulation Closed Circulation