Metamorphosis- amphibians, fishes, insects
• Biological process of animal’s growth and physical development through sages characterized by the change in body structure
Amniotic eggs - reptiles, birds, mammals
• The eggs are not laid in the water and contain membrane that covers the embryo (amnion)
Ectothermic scales - fishes, amphibians, reptiles, and invertebrates
• Body temperature depends on environment
Spinal cord – vertebrates
• a hollow tube of nervous tissue part of CNS
Gills in adults – insects, mollusks, crustaceans, amphibians, fishes
• respiratory organ in aquatic animals
Lungs in adults – birds, reptiles, mammals, some fishes and some amphibians
• respiratory organ for the extraction of oxygen from the atmosphere
External fertilization – amphibians and fishes, some invertebrates such as coral and sea anemones
• fertilization outside of the female's body (usually in water).
