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Vertebrate Classes All in Chordate Phylum. All vertebrates have…. Bilateral symmetry Fully developed coelom with organs Closed circulatory system Endoskeleton with spinal cord. Vertebrate Classes. Fish Amphibians Reptiles Birds Mammals. Orders of Fish. Lamprey and hagfish (jawless).
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All vertebrates have… • Bilateral symmetry • Fully developed coelom with organs • Closed circulatory system • Endoskeleton with spinal cord
Vertebrate Classes Fish Amphibians Reptiles Birds Mammals
Orders of Fish Lamprey and hagfish (jawless) bony fish Shark (cartilage)
Lampreys/HagfishJawless Fish • Lampreys attach to fish-parasites • Have “round sucker like mouths” • Hagfish are Scavengers of dead and dying fish on ocean bottom
Sharks, Skates, Rays • Jaws • The shark’s mouth has 6 to 20 rows of backward-pointing teeth • Some can detect blood from an injured animal as far as 500 miles away • No swim bladder
Bony Fish Most are familiar fishes and include snake-like eels, salmon, trout, bass, herring, tallapia and lantern fish (most fish we eat)
Bony Fish Fishes are the most numerous of all vertebrates and most widespread in their distribution Ectothermic
Obtain Oxygen • Fish obtain O2 through their gills • Fish can extract 85 % of the oxygen passing over the gills • Blood goes to the gills, is oxygenated and sent to all parts of the body • Single loop circulation in fish
Fish 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.
2 chamber heart The disadvantage of a 2 chambered heart is its slow delivery MUCH more energy required to move on land (or in air) = more O2 needed faster
Fish Reproduction Usually external fertilization Large numbers of eggs are fertilized during Spawning – when fish reproduce
Barndoor skate (Dipturus laevis) Cartilage Fish Skate Ectothermic Sharks, Skates and Rays fertilization is internal-most are born live Some sharks lay eggs
Variety of Rays There are many different types of rays including stingrays, electric rays, butterfly rays, round rays, manta rays, guitarfish, and sawfish.
Early aquatic adaptations • Teeth (everyone) – evolved from skin Shift from scavenging to predation (lampreys) • Jaws (sharks and bony fish) provide biting force
Later aquatic adaptations • Bony fish evolve swim bladder • This is an air bag that allows fish to move up and down in water-called buoyancy • sharks sink when not swimming • Swim bladder adapted to be lungs on land
Transitional fish / amphibian? • Tiktaalik roseae
Amphibians Salamander Frog Toad
Amphibians on land • Four legs are an adaptation to walk on land-These are adapted fish fins at right angles from body • Ectotherms- Body temperature the same as the surrounding temperature. • Hibernate or Estivate depending on climate
3 Chamber Heart 2 atria – 1 from body (deoxygenated), 1 from lungs (oxygenated) 1 ventricle – pumps blood to lungs and body O2 through lungs and moist skin called coetaneous respiration
3 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
Amphibian Reproduction • Must live near water for 2 reasons 1) External fertilization - Reproduce in water (lay eggs there) egg tadpole young frog adult Called Metamorphosis 2) Go to water to keep skin moist to obtain oxygen
Reptiles turtle crocodile snake
Adaptation-Claws • Strong, bony skeletons and toes with claws • Claws-aid in climbing, digging and movement in various terrains
More Reptile Adaptations • Adaptations evolved which allow reptiles to live totally on land. 1) Scales to prevent water loss 2) The most important adaptation for living on land is the amniotic egg
Eggs • Amniotic egg – has all the water and nutrients inside for embryo to survive
Reptile limitations • Disadvantage of Ectothermy: • Must live in warm areas • Cannot be active at night
Regulating Body Temperature • Ectotherm (“cold-blooded”) – animal does not maintain a constant body temperature Outside Temp = Body Temp
Ectothermy • Become sluggish in very cold temperature • Bask in the sun or seek shade
Advantages No energy used to keep warm Disadvantages Restricted to warm climates only Active only during day Ectothermy
Heart • Heart of most Reptiles-3 chambers • Disadvantage: Oxygenated and Deoxygenated blood mixes-less efficient • Crocodiles and alligators have a ventricle that is totally separated into two pumping chambers-4 chambers
Circulation Double loop circulation
Transitional bird / reptile • Archaeopteryx
Birds • Adaptations for Flight: Feathers, wings, hollow bones • Adaptation for living on land: Amniotic Egg like reptiles
Endothermy • Endotherm (“warm-blooded”) keeping a constant body temperature Advantages: • Can be active even in colder biomes • Can be active at night (nocturnal predators) Disadvantages: • Requires lots of energy (must find food often)
4 chamber heart 2 atria – 1 from body (deoxygenated), 1 from lungs (oxygenated) 2 ventricles – 1 pumps to lungs , 1 pumps to body
4 chamber heart • Even more energy needed for cells • Birds = energy for flight • Mammals = energy for large brains • NO mixture of blood in 4 chamber heart
Digestive 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
Respiratory System • Air enters nostrils at base of beakDown trachea past song boxenters two primary bronchiito lungs • 75% 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.
Adapations for Flight Air sacs allow birds to take in more oxygen for cellular respiration Hollow bones is a adaptation to decrease weight take in more oxygen for cellular respiration.
Transitional reptile / mammal Egg-laying Mammals or Monotremes Platypus