Unit 9 Chapter 30 Fishes and Amphibians What

Unit 9 Chapter 30 Fishes and Amphibians

What is a Fish? n Respiration using gills ¨ Blood moves in opposite direction to the flow of water, called counter current exchange n Two-chambered heart ¨ Atrium receives blood from body, & ventricle pumps blood to the gills

What is a Fish? n Paired fins for balance, swimming & steering n Scales for covering & protecting body n Spawning to produce millions of eggs to ensure a few will survive

What is a Fish? Well-developed sense organs: n Extremely sensitive sense of smell n Lateral line system to detect movement & vibrations n

Diversity of Fishes n Class Agnatha, the jawless fishes n Hagfish (scavengers) n Lampreys (external parasites)

Diversity of Fishes Class Chondrichthyes, the cartilage fishes n Skeletons composed entirely of cartilage n Include sharks, rays & skates n

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

What is an Amphibian? n n n Amphibia means “double life” Includes frogs, toads, salamanders & newts Ectotherms, has variable body temperature & gets its heat from external sources

What is an Amphibian? n Inefficient threechambered heart n Small inefficient lungs; respiration enhanced by “skin-breathing”

What is an Amphibian? n Metamorphosis: ¨ The larval forms resemble fish (2 chambered heart, fins, gills) n Vocal cords, sound -producing tissue in the male’s throat, used as a mating call