Kingdom Animalia Chordates

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Kingdom Animalia (Chordates)
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Phylum Chordata

• Most advanced group of animals
• Coelomate
• Deuterostomes
• Bilateral symmetry
• 3 well-developed tissue layers
• Endoskeleton
• Segmented body
• Jointed appendages
• Mouth and anus
• Closed circulatory system

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Distinguishing Characteristics

• 3 characteristics separate chordates from all
  other animal groups
• Notochorda firm, flexible, dorsal rod that
  supports the body found at some developmental
  stage in all chordates
• Nerve corda single dorsal, hollow cord of
  nervous tissue becomes the brain and spinal cord
  in vertebrates
• Gill slitsused for aquatic respiration found at
  some developmental stage in all chordates

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Subphyla

• 3 Subphyla in the Phylum Chordata
• Urochordataincludes the tunicate, or sea squirt
• Cephalochordataincludes the lancelet
• Vertebrataincludes fish, amphibians, reptiles,
  birds, and mammals

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Subphylum Urochordata

• Includes the tunicate, or sea squirt
• Marine
• Adults are sessile
• Sac-like body that looks somewhat like a sponge
• Has tadpole-like larvae that possess all 3
  chordate characteristics the adults do not

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Subphylum Cephalochordata

• Includes lancelets
• Marine found in shallow ocean waters may swim
  freely or burrow in the sand
• Small (several centimeters long), transparent,
  scale-less, fishlike animals
• Possesses all 3 chordate characteristics

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Subphylum Vertebrata

• Have a vertebral column, or backbone, which
  replaces the notochord this is made of
  vertebrae, bony segments that are stacked to form
  the backbone the vertebral column surrounds and
  protects the spinal cord
• Cranium, or skull, encloses and protects the brain

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Vertebrate Classes

• Class Agnathajawless fish such as the lamprey
  and hagfish
• Class Chondrichthyescartilagenous fish such as
  sharks, skates, and rays
• Class Osteichthyesbony fish such as perch, bass,
  trout, and catfish
• Class Amphibiaamphibians such as frogs, toads,
  and salamanders
• Class Reptiliareptiles such as snakes, lizards,
  turtles, crocodiles, and alligators
• Class Avesbirds
• Class Mammaliamammals such as dogs, cats,
  horses, cows, pigs, and humans

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Vertebrate Classes (cont.)

• Over half of all vertebrates are fish Agnatha,
  Chondrichthyes, and Osteichthyes are all classes
  of fish they are aquatic, so they breathe with
  gills they have a 2-chambered heart, consisting
  of an atrium and a ventricle
• Amphibia, Reptilia, Aves, and Mammalia are
  primarily terrestrial vertebrates they vary in
  the number of chambers to their hearts
• The fish, amphibians, and reptiles are all
  cold-blooded, or ectothermic birds and mammals
  are warm-blooded, or endothermic

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Class Agnatha

• Jawless fish (ex. Lamprey and hagfish)
• Mainly freshwater
• Breathe with gills
• Cylindrical, eel-like bodies with no scales or
  paired fins
• Lampreys are parasitic have round mouths that
  function like suction cups use teeth to bore
  into the skin of other fish and suck their blood
• Female lampreys swim upstream to lay their eggs
  (spawning), and then they die

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Class Chondrichthyes

• Fish with internal skeletons made of cartilage
  (which weighs less than bone) these fish must
  swim almost constantly or risk sinking
• Ex. Sharks, skates, and rays
• Primarily marine
• Breathe with gills
• Have jaws and paired fins
• Have internal fertilization most females retain
  the eggs and have live births

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Class Chondrichthyes (cont.)

• Sharks are carnivorous predators they feed on
  mollusks, crustaceans, and small fish have
  numerous rows of teeth, which are embedded in the
  skin (not in the jaws) and easily lost and
  replaced
• Skates and rays are scavengers they tend to stay
  near the ocean bottom

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Class Osteichthyes

• Fish with internal skeletons made of bone
• Ex. Perch, bass, trout, and catfish
• Some freshwater some marine
• Since bone is heavier than cartilage, these fish
  have swim bladders, gas-filled sacs that allow
  them to regulate their buoyancy they can remain
  suspended at any depth in the water
• Have jaws and paired fins
• Have a lateral line running the length of the
  body it helps the fish sense movement
• Most have a covering over the gills, an operculum

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Class Amphibia

• Ex. Frogs, toads, and salamanders
• Primarily terrestrial, but reproduction requires
  water eggs are laid in water, and the larvae
  (tadpoles) live in water external fertilization
• Metamorphosis occurs as a tadpole becomes an
  adult a tadpole breathes with gills, is
  herbivorous, and has a tail an adult breathes
  with lungs (and through the skin), is
  carnivorous, and loses its tail
• Have moist skin with mucus glands to keep the
  body from drying out
• Have a 3-chambered heart, consisting of 2 atria
  and 1 ventricle

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Class Reptilia

• Ex. Snakes, lizards, turtles, crocodiles, and
  alligators
• Primarily terrestrial do not require water to
  reproduce because they lay shelled eggs internal
  fertilization
• A reptile egg contains a membrane called the
  amnion, which encloses a fluid-filled cavity an
  embryo develops in this amniotic egg and is
  protected

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Class Reptilia (cont.)

• Have dry, scaly skin
• Breathe with lungs
• Have 3-chambered hearts, except for alligators
  and crocodiles, which have 4-chambered hearts
• Body temperature varies with the environment
  (cold-blooded), so many reptiles bask in the sun
  to absorb heat
• Dinosaurs were reptiles that became extinct

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Poisonous Snakes

• There are 3 types of poisonous snakes in our
  area
• Copperhead
• Rattlesnake
• Water Moccasin (Cottonmouth)

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Class Aves

• Birds (ex. Robin, woodpecker, bluejay, eagle,
  chicken, duck, owl)
• Primarily terrestrial, but some live near water
• Have feathers to assist in flying, but not all
  birds fly
• Have light, hollow bones to help with flying
• Breathe with lungs
• Warm-blooded
• Have a 4-chambered heart

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Class Aves (cont.)

• Have no teeth birds are adapted to their various
  feeding habits by the structure of their beaks
• Have internal fertilization
• Lay amniotic eggs
• Mating process is rather complex males have
  brightly-colored feathers and specific
  mating-calls to attract females
• Many birds migrate during the fall and spring

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Class Mammalia

• Ex. Dogs, cats, horses, cows, pigs, bats, whales,
  dolphins, and humans
• Primarily terrestrial, but some live in water
• Have hair/fur on their bodies during part of
  their lives
• Have mammary glands, which produce milk to
  nourish the young
• Internal fertilization

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Class Mammalia (cont.)

• Breathe with lungs
• Warm-blooded
• Have a 4-chambered heart
• Have differentiated teeth (incisors, canines,
  molars, and pre-molars)

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Class Mammalia (cont.)

• 3 main groups of mammals
• Monotremesegg-laying mammals (ex. spiny anteater
  and duckbilled platypus)
• Marsupialspouched mammals (ex. kangaroo and
  opossum)
• Placental Mammalsnourished within the mother by
  a placenta (ex. all other mammals)