<P> The term deep sea creature refers to organisms that live below the photic zone of the ocean . These creatures must survive in extremely harsh conditions, such as hundreds of bars of pressure, small amounts of oxygen, very little food, no sunlight, and constant, extreme cold . Most creatures have to depend on food floating down from above . </P> <P> These creatures live in very demanding environments, such as the abyssal or hadal zones, which, being thousands of meters below the surface, are almost completely devoid of light . The water is between 3 and 10 degrees Celsius and has low oxygen levels . Due to the depth, the pressure is between 20 and 1,000 bars . Creatures that live hundreds or even thousands of meters deep in the ocean have adapted to the high pressure, lack of light, and other factors . </P> <P> These animals have evolved to survive the extreme pressure of the sub-photic zones . The pressure increases by about one bar every ten meters . To cope with the pressure, many fish are rather small, usually not exceeding 25 cm in length . Also, scientists have discovered that the deeper these creatures live, the more gelatinous their flesh and more minimal their skeletal structure . These creatures have also eliminated all excess cavities that would collapse under the pressure, such as swim bladders . </P>

Most animals that live in deep oceanic water area