The deep sea is a very harsh environment. The light from the sun does not reach all the way to the deep sea, making it pitch black. The deep-sea is very cold, has low amounts of oxygen, and the pressure is very high. Food in the Deep Sea is very scarce. Due to these conditions species that live here found many ways to adapt to this environment
How do organisms in the deep sea find their way through the ocean without any sunlight?
How do these organisms adapt to the extremely high pressure of the deep sea?
How do organisms survive the intensely cold water temperatures of the deep sea?
The deep-sea temperature ranges from -1 to about +4°C. Life in the deep sea adapts to these extremely cold temperatures by having flexible proteins and unsaturated membranes that do not stiffen up in the cold. Membranes are made out of fat and are flexible to work well. For example, Butter, a saturated fat becomes hard in cold temperatures such as the refrigerator. On the other hand Olive oil, unsaturated fat is semi-solid, making a good flexible membrane. The pressure makes these fats to become more solid, enabling the fish in the deep sea to have a fish-like form. But once the creature is in a low pressured, higher temperature area the creature form will fall apart.
Food is significantly scarce in the deep sea. Scavengers on the ocean floor eat the decaying remains of microbes, algae, plants, and animals from above. The corpses of larger animals such as whales that sink to the bottom provide a feast to deep-sea animals such as jawless fish.