Vertebrates are animals with a backbone and an internal skeleton. Their skeleton consists of cartilage and bone, a skull with a brain, and limbs. The outer surface of their body is covered by feathers, skin, scales, fur or hair, or some combination of the above [source: Britannica]. There are five classes of vertebrates. The easiest way to determine what class a vertebrate belongs to is by looking at the body covering. Here is a list of the vertebrates' classes and the different body coverings.
Here are some of the characteristics of each class.
- Fish are ectothermic or cold-blooded [source: National Aquarium].
- Fish are often covered with scales.
- Fish have fins that give them stability.
- Fish breathe through their gills.
- Fish have tails that can either be curved, forked or crescent shaped.
- Fish have eyes on the sides of the head [source: National Aquarium].
- Amphibians are ectothermic or cold blooded.
- Amphibians have smooth thin skin, without scales, hair or feathers.
- Amphibians lay their eggs in water.
- Amphibian adults breathe with lungs and live outside water.
- Amphibians have a three-chambered heart.
- Amphibians have legs and a tail.
- Reptiles are ectothermic or cold blooded.
- Reptiles have skin with scales.
- Reptiles usually have a three-chambered heart, though some have four chambers.
- Reptiles have legs and a tail.
- Reptiles lay eggs in a sac [source: Georgia Perimeter College].
- Birds are endothermic or warm blooded
- Birds have skin that's covered with feathers.
- Birds have a four-chambered heart.
- Birds have wings.
- Birds lay eggs [source: Britannica].
- Mammals are endothermic or warm blooded
- Mammals have hair or fur.
- Mammals have mammary- or milk-secreting glands and they feed milk to their young.
- Nearly all mammals give birth to babies and do not lay eggs [source: Buffalo State University].