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The Animal Kingdom . The Chordates Nancy G. Morris Volunteer State Community College. Phylum Hemichordata. Hemichordata (hemi = half; chordata= cord) acorn worm entirely marine adults show 3 of 4 basic characteristics: 1) pharyngial pouches 2) dorsal tubular nerve chord 3) tail
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The Animal Kingdom The Chordates Nancy G. Morris Volunteer State Community College
Phylum Hemichordata Hemichordata(hemi = half; chordata= cord) • acorn worm • entirely marine • adults show 3 of 4 basic characteristics: 1) pharyngial pouches 2) dorsal tubular nerve chord 3) tail • evolutionary link between echinoderm and chordates • ciliated larvum resembles tornaria larvum of echinoderms
Phylum Chordata • Subphylum Urochordata (uro = tail; chordata= cord) • Subphylum Cephalochordata (cephalo = head; chordata= cord) • Subphylum Vertebrata (vertebrate = backbone)
Phylum Chordata • All exhibit four chordata characteristics: • 1) dorsal tubular nerve cord • 2) notochord • 3) pharyngial pouches • 4) tail • Deutrostomes – chordates & echinoderms
Subphylum Urochordata • sea squirts or tunicates • notochord present only in free-swimming larvum • notochord does not extend into head • larvum is free-swimming but non-feeding • adult is sessile filter feeder
Subphylum Urochordata • sea squirts or • tunicate • Campbell p 631 • Settle after brief free-swimming larvum existence. Attaches at anterior end. Metamorphosis begins. Body turns 1800. Tail, notochord, dorsal nerve cord, disappear.
Subphylum Cephalochordata • “head” cord • lancelet or Amphioxus • notochord present throughout life – extends into head region • shallow marine waters • chordate characteristics developed and apparent in adult • tail has blocks of muscles called myotomes • adults resemble tunicate larvum
Subphylum Vertebrata General Characteristics: • chordates with a backbone • exhibit cephalization • closed circulatory system • neural crest (p. 633)
Subphylum Vertebrata Agnatha(without jaws) • lamprey – parasitic bloodsuckers w/ rasping tongue • hagfish – mainly scavengers • no paired appendages • larvum resembles lancelet
Subphylum Vertebrata Chondrichthyes(cartilaginous fishes) • flexible endoskeletons of cartilage strengthened by calcium granules • sharks (internal fertilization) • oviparous – egg laying • ovoviviparous – retain fertilized eggs hatch within the uterus • viviparous – young develop in the uterus • suspension-feeders (plankton)
Phylum Hemichordata Hemichordata(hemi = half; chordata= cord) • acorn worm • entirely marine • adults show 3 of 4 basic characteristics: 1) pharyngial pouches 2) dorsal tubular nerve chord 3) tail • evolutionary link between echinoderm and chordates • ciliated larvum resembles tornaria larvum of echinoderms
Phylum Chordata • Subphylum Urochordata (uro = tail; chordata= cord) • Subphylum Cephalochordata (cephalo = head; chordata= cord) • Subphylum Vertebrata (vertebrate = backbone)
Phylum Chordata • All exhibit four chordata characteristics: • 1) dorsal tubular nerve cord • 2) notochord • 3) pharyngial pouches • 4) tail • Deutrostomes – chordates & echinoderms
Subphylum Urochordata • sea squirts or tunicates • notochord present only in free-swimming larvum • notochord does not extend into head • larvum is free-swimming but non-feeding • adult is sessile filter feeder
Subphylum Urochordata • sea squirts or • tunicate • Campbell p 631 • Settle after brief free-swimming larvum existence. Attaches at anterior end. Metamorphosis begins. Body turns 1800. Tail, notochord, dorsal nerve cord, disappear.
Subphylum Cephalochordata • “head” cord • lancelet or Amphioxus • notochord present throughout life – extends into head region • shallow marine waters • chordate characteristics developed and apparent in adult • tail has blocks of muscles called myotomes • adults resemble tunicate larvum
Subphylum Vertebrata General Characteristics: • chordates with a backbone • exhibit cephalization • closed circulatory system • neural crest (p. 633)
Subphylum Vertebrata Agnatha(without jaws) • lamprey – parasitic bloodsuckers w/ rasping tongue • hagfish – mainly scavengers • no paired appendages • larvum resembles lancelet
Subphylum Vertebrata Chondrichthyes(cartilaginous fishes) • flexible endoskeletons of cartilage strengthened by calcium granules • sharks (internal fertilization) • oviparous – egg laying • ovoviviparous – retain fertilized eggs hatch within the uterus • viviparous – young develop in the uterus • suspension-feeders (plankton)
Subphylum Vertebrata Chondrichthyes (cartilaginous fishes) • Rays & skates • Bottom feeders – mollusks & crustaceans • Whiplike tail w/ venomous barbs (defense)
Subphylum Vertebrata Chondrichthyes (cartilaginous fishes) • Rays & skates • Bottom feeders – mollusks & crustaceans • Whiplike tail w/ venomous barbs (defense)
Subphylum Vertebrata Osteichthyes (bony fishes) • Endoskeleton of hard calcium phosphate matrix • Operculum- protective flap • Swim bladder – controls buoyancy
Subphylum Vertebrata Amphibia (“two lives”) • first tetrapods • transition to land – still tied to water for respiration and reproduction • Gills lungs (metamorphosis) • Frogs, toads, salamanders, newts
Subphylum Vertebrata Reptilia(Campbell, p. 644) (to creep) • lizards, snakes, turtles, tortoises, Gila monsters, crocodiles, alligators • first true land animal • Scales, lungs, amniotic egg • no feathers • cold-blooded – ectotherms – (energy conservation)
Subphylum Vertebrata Fossil links………… • Evolutionary link ?? between reptiles and birds: Archaeopteryx , a Jurassuc bird-reptile • Clawed forelimbs • Teeth • Long tail w/ vertebrae
Subphylum Vertebrata Aves (bird) • feathered • few flightless: ostrich, kiwi, emu • breastbone with keel – carina – permitting flight • jays, sparrows, warblers, etc
Subphylum Vertebrata Mammalia(breast) • Hair or fur of keratin • Active metabolism = endothermic • Efficient respiration w/ diaphragm • Efficient circulation w/ 4-chambered heart • Layer of fat • Mammary glands, tooth differentiation
Subphylum Vertebrata Mammalia(breast) • Monotremes – egg-laying mammals (Platypuses & echidnas – spiny anteaters) • Placental mammals • Marsupial mammals – kangaroo, opossum
Marsupial Placental Marsupial &PlacentalMammals