User:Alicejin13/Deep sea creature

Diving Physiology for Pressure Adaptations
When it comes to deep sea diving, there is an increase in pressure as fish swim down the water column. Most marine mammals give in to and absorb the pressure and do so by gaining new functions through evolution. For example, the lungs of deep sea creatures can be compressed in to a solid organ. As the chest wall compresses, the lungs collapse and the gas in the alveoli is forced into the upper airways, where gas exchange does not occur. Some other evolutionarily adapted function are the lack of air sinuses in the skull and a reduction in the internal air space volume of the middle ear. This is so it can match that of the ambient pressure. In addition, the vascular lining of the middle ear can expand as pressure goes up.

Pelagic fish usually have no swim bladder or a swim bladder filled with fat beyond a depth of 1000 meters. The loss of the swim bladder contributed to saving energy, because it was costly to pump gas into the bladders at great depths of the ocean.

Deep sea creatures also have less muscle and ossified bone. This lack of ossification was adapted to save energy when there isn't an abundance of food in the environment.

Another adaptation deep sea fish evolved to have is an enlarged aortic arch or bulb. This helps absorb a lot of the energy used during systole by the left ventricle. The absorbed pulse is more evenly spread throughout the rest of the cardiac cycle, especially during bradycardia.

Hydrostatic Pressure
Hydrostatic pressure in the deep sea comes hand-in-hand with low temperatures, high inorganic nutrients, and low organic carbon content. This is disadvantageous since the deep-sea food web is dependent on particulate organic carbon, which is in the euphotic zone. In addition, metabolic activity decreases with an increase in hydrostatic pressure due to the limits in degrading organic matter sinking through the water column.