General purpose of this lecture is to present on Vertebrates. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 64,000 species described. Common Vertebrates are fishes and amphibians. Fish: Chambers in their heart: two; Structures for movement: Fins; Reproduction: Lay eggs in the water and Organ that keeps them afloat: Swim bladder. Amphibians: Spend part of their lives in water and part on land; Do not have scales or hair and Some have tails throughout life and some lose their tail.