What adaptations allow fish to live in extreme conditions of existence? Confirm with examples.

Fish are adapted to exist in an aquatic environment with its characteristics: pressure, salinity, current, density, lack of light at depth, and others. Deep sea fish have adapted to the high water pressure. They are usually flattened, have very large eyes that can capture even small light particles, and some fish have luminous organs. The speed of the fish is opposed with the help of highly developed muscles and motor limbs (fins). Some fish are able to be without water for a long time or, when the reservoir dries up, switch to breathing using the surface of their bodies.