- Buoyant Force: the force water exerts upward on any underwater object.
- Cartilage: connective tissue that is soft, flexible and strong.
- Ectotherm: an animal whose body temperature of its environment
- Endotherm: an animal whose body temperature is maintained at a steady temperature
- Notochord: a flexible rod that supports the body.
- Swim Bladder: an internal gas-filled sac that helps fish to swim at different depths.
- Vertebrae: bone that makes up the backbone