Why a shark is a living thing?

Why do tiger sharks swim up on the back of tail? What stabilizes fish at different levels of water? How long is a 150 gallon fish tank? What color are clown fish eggs? What are rays that live in the ocean? What causes air bubbles to form on the leaves in a fish bowl left under direct sunlight? What does the barreleye fish eats? How cartilaginous fish conserve energy? What is the proper meaning of redfish according to online sources? What is a good easy to take care of animal for a 35 gallon tank? What is the similarity and difference between the reproduction process of a human and goldfish? What watts dose the heater have to be in a turtle tank? What type of ocean does a piranha live? Is a swordfish solitary or social? How many types of pirouette? From what height can you survive a dive into water? Why cant you put regular pieces of wood in your aquarium? How does a pygmy seahorse effect humans? How many syllables does goldfish have? What are the uses of marine life?