Unit 9 Chapter 30 Fishes and Amphibians

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Unit 9Chapter 30Fishes and Amphibians
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What is a Fish?

• Respiration using gills
• Blood moves in opposite direction to the flow of
  water, called counter current exchange
• Two-chambered heart
• Atrium receives blood from body, ventricle
  pumps blood to the gills

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What is a Fish?

• Paired fins for balance, swimming steering
• Scales for covering protecting body
• Spawning to produce millions of eggs to ensure a
  few will survive

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What is a Fish?

• Well-developed sense organs
• Extremely sensitive sense of smell
• Lateral line system
  to detect movement
  vibrations

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Diversity of Fishes

• Class Agnatha, the jawless fishes
• Hagfish (scavengers)
• Lampreys (external parasites)

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Diversity of Fishes

• Class Chondrichthyes, the cartilage fishes
• Skeletons composed entirely of cartilage
• Include sharks, rays skates

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Diversity of Fishes

• Class Osteichthyes, the bony fishes
• Includes catfish, perch, salmon, sea horses,
  lionfish, etc
• Swim bladder, gas-filled sac that enables
  fish to control buoyancy

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What is an Amphibian?

• Amphibia means double life
• Includes frogs, toads, salamanders newts
• Ectotherms, has variable body temperature
  gets its heat from external sources

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What is an Amphibian?

• Inefficient three-chambered heart
• Small inefficient lungs respiration enhanced by
  skin-breathing

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What is an Amphibian?

• Metamorphosis
• The larval forms resemble fish (2 chambered
  heart, fins, gills)
• Vocal cords, sound-producing tissue in the
  males throat, used as a mating call