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.
Tardigrades (Tardigrada), also known as water bears or moss piglets, are a phylum of small invertebrates. They were first described by the German pastor J.A.E. Goeze in 1773 and given the name Tardigrada, meaning slow stepper, three years later by the Italian biologist Lazzaro Spallanzani. Tardigrades are short (0.05mm - 1.2mm in body length), plump, bilaterally symmetrical, segmented organisms.