10Obtain Oxygen Fish obtain O2 through their gills Fish can extract 85 % of theoxygen passing over the gillsBlood goes to the gills, is oxygenated and sent to all parts of the bodySingle loop circulation in fish
11Fish have a two chambered heart. This is efficient for the fish since it is in water, but would not work for land animals who need more energy.
122 chamber heartThe disadvantage of a 2 chambered heart is its slow deliveryMUCH more energy required to move on land (or in air) = more O2 needed faster
13Fish Reproduction Usually external fertilization Large numbers of eggs are fertilized during Spawning – when fish reproduce
15Cartilage Fish Ectothermic Barndoor skate (Dipturus laevis)Cartilage FishEctothermicSharks, Skates and Rays fertilization is internal-most are born liveSome sharks lay eggsSkate
16Variety of Rays There are many different types of rays including stingrays,electric rays,butterfly rays, round rays,manta rays, guitarfish,and sawfish.
17Early aquatic adaptations Teeth (everyone) – evolved from skinShift from scavengingto predation (lampreys)Jaws (sharks and bony fish)provide biting force
18Later aquatic adaptations Bony fish evolve swim bladderThis is an air bag that allows fish to move up and down in water-called buoyancysharks sink when not swimmingSwim bladder adapted to be lungs on land
23Amphibians on landFour legs are an adaptation to walk on land-These are adapted fish fins at right angles from bodyEctotherms- Body temperature the same as the surrounding temperature.Hibernate or Estivate depending on climate
243 Chamber Heart2 atria – 1 from body (deoxygenated), 1 from lungs (oxygenated)1 ventricle – pumps blood to lungs and bodyO2 through lungs and moist skin called coetaneous respiration
253 chamber heart Advantage of a 3 chambered heart Blood getting to body cells faster (heart pumps directly to body)Disadvantage of a 3 chambered heart:Deoxygenated blood mixes with oxygenated blood in atria
26Amphibian Reproduction Must live near water for 2 reasons1) External fertilization - Reproduce in water (lay eggs there)egg tadpole young frog adultCalled Metamorphosis2) Go to water to keep skin moistto obtain oxygen
33EggsAmniotic egg – has all the water and nutrients inside for embryo to survive
34Reptile limitations Disadvantage of Ectothermy: Must live in warm areasCannot be active at night
35Regulating Body Temperature Ectotherm (“cold-blooded”) –animal does not maintain a constant body temperatureOutside Temp = Body Temp
36Ectothermy Become sluggish in very cold temperature Bask in the sun or seek shade
37Ectothermy Advantages Disadvantages No energy used to keep warm Restricted to warm climates onlyActive only during day
38Heart Heart of most Reptiles-3 chambers Disadvantage: Oxygenated and Deoxygenated blood mixes-less efficientCrocodiles and alligatorshave a ventricle that is totally separated into two pumping chambers-4 chambers
42Birds Adaptations for Flight: Feathers, wings, hollow bones Adaptation for living on land:Amniotic Egg like reptiles
43Endothermy Endotherm (“warm-blooded”) keeping a constant body temperatureAdvantages:Can be active even in colder biomesCan be active at night(nocturnal predators)Disadvantages:Requires lots of energy(must find food often)
454 chamber heart2 atria – 1 from body (deoxygenated), 1 from lungs (oxygenated)2 ventricles – 1 pumps to lungs , 1 pumps to body
464 chamber heart Even more energy needed for cells Birds = energy for flightMammals = energy for large brainsNO mixture of blood in 4 chamber heart
47Digestive and Excretory system Food passes from the mouth cavity straight to the esophagus.The crop stores and moistens food.Then passes through the gizzard, a muscular organ that kneads and crushes the food
48Respiratory SystemAir enters nostrils at base of beakDown trachea past song boxenters two primary bronchiito lungs75% bypasses the lungs and flows directly to posterior to sacssacs connect with air spaces in bones, filling the hollow bones with air.When bird exhales the carbon dioxide rich air from the lungs, oxygen rich air is forced out of the posterior air sacs into lungs.
49Adapations for FlightAir sacs allow birds to take in more oxygen for cellular respirationHollow bones is a adaptation to decrease weight take in more oxygen for cellular respiration.
50Transitional reptile / mammal Egg-laying Mammals or MonotremesPlatypus
53Evolution and Adaptations Mammals belongto the class Mammalia, which includes 4000 speciesMost dominant land animals on earth.
54Circulatory System Mammalian heart has 4 chambers Mammals have a muscle , the diaphragm that aids in lung breathing
55Adaptations that distinguish Mammals from other vertebrates: Hair which helps in insulationMammary glands that produce milk for the young.
56Mammals 19 orders of mammals 17 nourish unborn young by the placenta The others are: egg laying Monotremes and Marsupials
57MarsupialsMarsupials give birth to tiny immature young that crawl to a pouch on the mothers belly immediately after they are born.
58Characteristics of Placental Mammals Placental mammals carry unborn young in the uterus until young can survive in the wild.Oxygen and nutrients are transferred from mother’s blood to baby’s blood
59Placental Characteristics The placenta is a membrane providing oxygen and nutrients and removal of CO2 and waste between the mother and developing youngGestation period is the time which mammals develop in mother’s uterus
60Mammals Hairy Armadillo Also endothermic Hairy Saki-MonkeyAlso endothermicHair helps to insulate, maintain internal body temperatureParaguaian HairyDwarf PorcupineHairy Armadillo
61Mammals Large brain size (learning / communicating) Disadvantage: longer time needed for brain developmentSolution: longer gestation period in mom and intensive parental care early on (including milk from mammary glands)