How do dolphins breathe?
Although dolphins are not fish, it is important to stress that they do not breathe like human beings. Unlike land mammals, dolphins do not have involuntary respiration. These aquatic animals have to reckon with the fact that they have to go up out of the water to get air. To do this, they rise to the surface and open the spiracle also known as a nostril, a hole they have above their heads. This nostril is directly connected to the trachea, which, in general, is shorter than the terrestrial mammals.
On average, dolphins take half a second to exhale all the air and half a second to inspire. If you do a test, we humans take much longer to completely fill our lungs and empty them again, about six seconds, if we take less, we could hyperventilate.
Anatomically, the lungs of dolphins are different from those of land mammals. Each mammal has its lungs divided into different lobes, while dolphins are not.
Where do dolphins breathe from?
As we said before, dolphins take air through the spiracle, which is led to the lungs through a shorter trachea and bronchi.
Now, once we have figured out where the dolphins breathe, what are the lungs of the dolphins like? There are two main differences between the lungs of cetaceans, the group to which dolphins belong, and those of land mammals:
1. The first difference is directly in the lungs. These organs are present in mammals living on earth, in particular, we note the presence of 3 lobes in the right lung and 2 in the left. On the contrary, in the dolphins this division does not exist.
2. The second difference, on the contrary, can be seen at the micro-anatomic level. The lungs of the dolphins lack lobules and bronchioles, which is not the case in terrestrial mammals.
How do dolphins breathe in water?
Dolphins do not breathe in water, however, I can resist in water without breathing. To understand how dolphins breathe, it is important to know that when a dolphin dives underwater, there are a number of physiological changes that allow it to remain without breathing for a period of time. In general, a dolphin does not remain underwater for more than half a minute without breathing, although, depending on the species, it can remain underwater for up to 10 minutes.
During underwater swimming, dolphins produce the so-called "diving reflex". This physiological mechanism consists of a deep bradycardia (decrease in heart rate). Nevertheless, it has been shown that both the brain and lungs continue to receive the same amount of blood, but the heart deviates part of what corresponds to the muscles to maintain good oxygenation and to be able to continue swimming.
If the dolphin remains immersed for a long time or the diving sessions are too continuous, other biochemical changes begin to occur. On the one hand, there is an accumulation of lactic acid from the muscles and the blood is acidified, which can be a problem. On the other hand, the oxygen concentration in the blood decreases. To counteract this situation, there are a number of reactions linked to glycolic enzymes that guarantee the production of energy, to continue to move the muscles and, for anaerobic disease, the lactic acid produced is eliminated.
How do dolphins sleep?
Dolphins have a special way of sleeping, we could say that they sleep with one eye open. This type of sleep is known as unihemispheric. While half of the brain sleeps, the other half still works. So how do dolphins breathe when they sleep? Very simple, thanks to this type of sleep, dolphins, which are animals that breathe voluntarily, can sleep and breathe at the same time. While one part of the brain rests, the other part is responsible for keeping the body in constant interaction with its environment so that it can re-emerge and breathe.
Dolphin Breathing
Dolphins perform synchronous respiration when in a group, especially if there are very young individuals. Through this breathing method, all individuals in the herd come out to catch their breath almost simultaneously. A study has shown that the presence of maritime traffic increases this synchrony even if the consequences are still unknown. What is, however, an important fact is that the presence of heavy maritime traffic causes changes in the behaviour of dolphins.
Dolphins are social animals that swim daily for over 50 nautical miles, with highly developed brains and extraordinary intellectual complexity, so they should never be kept in dolphinariums. But they must live in freedom, with their family and friends.