Vertebrates Notes PDF

Kingdom Animalia: Vertebrates  Phylum Chordata (chordates) most chordates are vertebrates (except for nonvertebrate chordates, e.g. tunicates and lancelets)  Phylum Chordata (chordates) all chordates share four key characteristics: 1) dorsal hollow nerve cord 2) notochord...

Kingdom Animalia: Vertebrates  Phylum Chordata (chordates) most chordates are vertebrates (except for nonvertebrate chordates, e.g. tunicates and lancelets)  Phylum Chordata (chordates) all chordates share four key characteristics: 1) dorsal hollow nerve cord 2) notochord 3) pharyngeal pouches 4) postanal tail vertebrate embryo  What do these embryonic structures become? 1) dorsal hollow nerve cord → becomes brain and spinal cord 2) notochord → becomes vertebrae of most adult vertebrates 3) pharyngeal pouches → becomes gills (in fish) or auditory canal and various glands (e.g. tonsils, parathyroid, thymus, thyroid) 4) postanal tail → becomes tail or tailbone  Types of Vertebrate Chordates There are 8 classes of vertebrate chordates: 1) Class Myxini (hagfishes) 2) Class Cephalaspidomorphi (lampreys) 3) Class Chondrichthyes (cartilaginous fishes) 4) Class Osteichthyes (bony fishes) 5) Class Amphibia (amphibians) 6) Class Reptilia (reptiles) 7) Class Aves (birds) 8) Class Mammalia (mammals) Q: Which classes above are “cold-blooded”? “warm- blooded”?  Temperature Control Ectothermic Endothermic “cold-blooded” “warm-blooded” ectotherms rely on external endotherms rely on internal heat heat gain heat from environment generate heat by metabolism low body temperature high body temperature low metabolic rate high metabolic rate burn few calories burn lots of calories lack insulation insulated examples: fish, amphibians, examples: birds and mammals reptiles  Fishes Class Myxini (hagfishes) Class Cephalaspidomorphi (lampreys) Class Chondrichthyes (cartilaginous fishes) Class Osteichthyes (bony fishes)  Fishes Characteristics: aquatic gills most have scales two chambered heart ectothermic types of egg development: 1) oviparous – eggs develop outside female 2) ovoviviparous – eggs develop inside female 3) viviparous – young nourished directly by mother’s body  Class Myxini (hagfishes) Characteristics: jawless, circular mouth with short tentacles lack scales possess notochord as adults mostly scavengers EXTREMELY slimy  Class Cephalaspidomorphi (lampreys) Characteristics: jawless, circular mouth lined with rasping teeth lack scales possess notochord as adults larvae are filter feeders; adults are parasites  Class Chondrichthyes (cartilaginous fishes) Characteristics: jawed endoskeleton of cartilage shark tough scales examples: sharks, rays and skates ray skate  Class Osteichthyes (bony fishes) Characteristics: jawed bony endoskeleton scales gills (some have lungs!) two groups: 1) ray-finned fishes 2) lobe-finned fishes  Class Osteichthyes: 1) Ray-Finned Fishes Characteristics: fins contain slender bony spines called “rays” includes almost all bony fish (e.g. salmon, perch, sturgeon, tuna, goldfish, eel)  Class Osteichthyes: 2) Lobe- Finned Fishes Characteristics: fins are fleshy and contain limb-bones includes lungfish and coelacanth lungfish coelacanth Class Amphibia Salamanders Frogs & Toads Legless Amphibians  Class Amphibia (amphibians) Characteristics: smooth, moist, porous skin with glands lack scales and claws larvae are aquatic and breathe through gills; adults are terrestrial and breathe through lungs and skin three chambered heart ectothermic urogenital opening is cloaca most are oviparous; eggs lack a shell Orders: salamanders, frogs & toads, legless metamorphosis amphibians  Salamanders Characteristics: possess tail as adults usually have four legs salamander some have gills as adults (e.g. mud puppy, axolotl) mud puppy  Frogs & Toads Characteristics: adults lack tails aquatic larvae are called tadpoles hind legs are adapted for frog jumping frogs have smooth skin and longer legs; toads have bumpy skin and shorter legs toad  Legless Amphibians Characteristics: lack legs wormlike, terrestrial burrowers live in tropics caecilian  Class Reptilia Tuatara Lizards & Snakes Crocodilians Turtles & Tortoises  Class Reptilia (reptiles) Characteristics: adapted to dry land dry scaly skin, claws lungs ectothermic three or four chambered heart urogenital opening is cloaca amniotic egg (contains leathery shell, yolk, allantois, chorion, amnion) oviparous or ovoviviparous Reptilian skin and claws Orders: tuatara, lizards & snakes, crocodilians, turtles & tortoises Amniotic Egg  Tuatara Characteristics: retain features of prehistoric reptiles lack ears primitive scales teeth are projections of jawbone contain a “third eye” (pineal gland) tuatara only one species  Snakes & Lizards Characteristics: lizards typically have legs snakes lack legs snake examples: iguana, gecko, cobra, python, boa lizard  Crocodilians Characteristics: four chambered heart alligators and caimans live only in fresh water; crocodiles may live in fresh or salt water examples: alligator, crocodile, caiman  Turtles & Tortoises Characteristics: bony shell ribs and vertebrae fused to shell turtles swim, tortoises don’t Class Aves  Class Aves (birds) Characteristics: feathers: 1) contour feathers 2) down feathers 3) powder feathers scales on legs and feet bones hollow and lightweight in flying penguin species well-developed lungs and air sacs endothermic four chambered heart urogenital opening is cloaca oviparous examples: owl, eagle, duck, chicken, pigeon, penguin, sparrow, stork pigeon Respiratory System of Birds Class Mammalia Monotremes Marsupials Placentals  Class Mammalia (mammals) Characteristics: mammary glands produce milk conserve body heat (fur, hair, subcutaneous fat) endothermic lungs diaphragm divides thoracic and abdominal cavities four chambered heart most are viviparous types: monotremes, marsupials, placentals 4 Chambered Heart  Monotremes (egg-laying mammals) Characteristics: reptilian features: e.g. possess cloaca, lay eggs (oviparous) duck-billed platypus mammalian features: e.g. produce milk from primitive nipplelike structures short-beaked echidna Marsupials (pouched mammals) Characteristics: viviparous embryo uses up yolk in uterus, then crawls into a pouch opossum kangaroo (marsupium) examples: opossum, kangaroo, koala koala Placentals (placental mammals) Characteristics: viviparous young develop to term in uterus, nourished through placenta Orders: insectivores, bats, primates, edentates, lagomorphs, rodents, cetaceans, carnivores, elephants, sirenians, odd-toed ungulates, even-toed ungulates  Orders of Placental Mammal Insectivores Bats Primates Edentates Lagomorphs Rodents Cetaceans Carnivores Elephants Sirenians Odd-toed ungulates Even-toed ungulates  Insectivores Characteristics: long, narrow snouts sharp claws for digging examples: shrew, mole, hedgehog hedgehog  Bats Characteristics: flying mammals; forelimbs adapted for flight most nocturnal most navigate by echolocation vampire bat examples: fruit bat, flying fox, vampire bat  Primates Characteristics: highly developed brain complex social behaviour excellent binocular vision quadrupedal or bipedal five digits on hands and feet examples: lemur, monkey, chimpanzee, monkey human  Edentates Characteristics: teeth reduced or absent feed primarily on termites and ants examples: anteater, armadillo anteater  Lagomorphs Characteristics: small herbivores with chisel-shaped front teeth adapted to running and jumping examples: rabbit, pika, hare hare  Rodents Characteristics: mostly herbivorous but some omnivorous sharp front teeth examples: rat, beaver, guinea pig, hamster, gerbil, squirrel beaver Rat Anatomy  Cetaceans Characteristics: aquatic, but have lungs forelimbs specialized as flippers; hindlimbs absent some use echolocation communicate using complex auditory signals examples: whale, porpoise, dolphin porpoise  Carnivores Characteristics: mostly carnivorous aquatic or terrestrial examples: seal, bear, raccoon, weasel, skunk weasel  Elephants Characteristics: herbivorous have trunks largest land animal examples: Asian elephant, African elephant African elephant  Sirenians Characteristics: aquatic herbivores, but have lungs slow-moving forelimbs modified as flippers; hindlimbs absent examples: manatee, manatee sea cow  Odd-Toed Ungulates Characteristics: hoofed, odd number of digits on each foot herbivores digestive system adapted to plant material examples: horse, horse hoof donkey, rhinoceros, tapir  Even-Toed Ungulates Characteristics: hoofs derived from two digits on each foot herbivores digestive system adapted to plant material examples: sheep, cow, hippopotamus, antelope, camel, giraffe, pig cow hoof Predation  Adaptations of Predators and Prey Predation is when a predator kills and eats the prey. Prey adaptation: Predator adaptation: Predator Prey Interaction – Hare and Lynx Q: What can you infer from the growth curves of each organism?  Predation Capture Strategies - Examples 1) Ambush – surprise 2) Ballistic Interception – attack predicts motion of prey 3) Pursuit – chase of prey 4) Lunge Feeding – accelerating with mouth open Vertebrate Systems  Vertebrate Systems Major vertebrate systems: digestive system circulatory system respiratory system excretory system nervous system Digestive System Circulatory System – heart  Circulatory System – gills vs lungs Single-Loop – uses gills Double-Loop – uses lungs Respiratory System Excretory System Nervous System – Brain Human Brain (text pgs. 817- 820)