Sperm Storage: Dolphins conserve their oxygen during dives by temporarily halting or slowing down their heart rate and metabolism, reducing their oxygen requirements. This ability is known as bradycardia. It may decrease their internal metabolic processes, allowing them to stay submerged longer.
Blood Reserves: Dolphins have a higher volume of blood than terrestrial mammals, accounting for about 10-12% of their body weight. This increased blood volume allows them to store more oxygen and distribute it efficiently throughout their bodies.
Myoglobin: Muscles cells of dolphins have high concentrations of myoglobin, a protein that binds to oxygen and facilitates its diffusion within tissues. This enables dolphins to continue functioning even when oxygen levels are relatively low.
Efficient Lungs: Dolphins have specialized lungs capable of rapidly absorbing oxygen from the air during brief periods at the surface. They take shallow, rapid breaths and have efficient ventilation systems to maximize oxygen uptake in a short time.
Diving Reflex: Dolphins trigger the diving reflex when they submerge into water. This reflex automatically slows their heart rate, redirects blood flow to vital organs, and reduces oxygen consumption. It's a vital adaptation that helps them survive underwater with minimal energy expenditure.
Blubber: Blubber, the layer of fat beneath their skin, also has insulation properties that aid in maintaining body heat. This is particularly important in colder waters where dolphins need to conserve energy to stay warm while diving.
By combining these adaptations, dolphins can effectively manage their oxygen consumption, store oxygen efficiently, and conserve internal resources during dives, allowing them to remain underwater for extended durations.