Although the terms reactant and reagent are often used interchangeably, a reactant is more specifically a substance that is consumed in the course of a chemical reaction. Solvents, although they are involved in the reaction, are usually not referred to as reactants.
Animals that live in water, usually called aquatic animals, include fish, cetaceans, certain types of turtles and other reptiles, and amphibians. There are also a number of semiaquatic animals, such as alligators, hippopotamuses and penguins, that depend on and live in water most of the time. Continue Reading.
But another creature, dubbed 'nature's greatest survivor,' is even more invincible, and you've probably never even heard of it. Tardigrades, also known as water bears, are some of the most fascinating animals in world because they can live happily in the most extreme conditions.