Seals have nostrils that close underwater to prevent water from entering their airways, allowing them to dive and hunt underwater without the risk of suffocation.
Seals have a unique anatomy with specially designed nostrils that can completely close when they dive underwater. The trick? Powerful muscles control the opening and closing of the nostrils, allowing them to effectively block the flow of water. This mechanism is somewhat like a watertight valve: as soon as the seals submerge, the nostrils close tightly, protecting their respiratory system. Conversely, when they come up to breathe at the surface, they can open them instantly to quickly resume their breath. Handy for not drowning while hunting or during aquatic training!
Underwater, the seal tightly closes its nostrils to prevent water from entering its airways. Since it can hold its breath for a long time when diving, it's essential to keep its lungs dry! By closing its nostrils, it also avoids losing precious air unnecessarily. This clever reflex of closing the nostrils activates automatically as soon as it dives, with no need to think about it each time. This allows it to hunt effectively, without the risk of swallowing or accidentally breathing in water. For it, it's a matter of survival, period.
Thanks to their closing nostrils, seals can hunt underwater without fearing that water will enter their airways. This is an obvious advantage for effectively pursuing their prey, which is often very fast and agile, like fish and squid. This adaptation allows seals to dive longer and deeper while conserving their precious oxygen, all while avoiding the uncomfortable or painful sensations associated with water entering their nose. Essentially, perfectly sealed nostrils mean a better chance of catching prey, leading to improved survival.
Other marine mammals also have the same concern for sealing, but with different anatomical strategies. Whales and dolphins, for example, use a blowhole located on the top of their skull, a kind of rapid valve that closes tightly when they dive. Manatees, on the other hand, also close their nostrils with specialized muscles, but with less efficiency than seals. Sea otters, for their part, must actively hold their breath and voluntarily control the closing of their nostrils, without a sophisticated automatic valve system like that of the seal. Each marine mammal has therefore developed a solution adapted to its habitat and hunting habits.
Seals can hold their breath underwater for over 30 minutes, thanks in particular to their ability to perfectly close their nostrils.
Unlike humans, seals have specialized muscles that allow them to voluntarily close their nostrils to prevent water from entering while they dive.
Did you know that elephant seals, cousins of seals, can dive to depths exceeding 1,500 meters and can close their nostrils using similar mechanisms?
When they dive, seals reduce their heart rate to conserve oxygen, a remarkable physiological adaptation that complements the airtight closure of their nostrils.
No, the sense of smell is generally not used underwater by seals, as odors have difficulty dispersing in water. Seals rely more on their sensitive whiskers (vibrissae) to detect movements and prey in their aquatic environment.
In addition to their watertight nostrils, seals are specially adapted to aquatic life thanks to their powerful flippers, their streamlined bodies reduce water resistance, and their thick layer of insulating fat effectively protects them against the cold.
No, seals do not have gills and can therefore only breathe outside of the water. They close their nostrils when they dive to prevent water from entering their airways and only open them at the surface when they breathe.
Depending on the species, a seal can stay underwater for an average of 15 to 30 minutes, but some species, such as the Weddell seal, can remain submerged for up to about an hour without breathing due to an efficient storage of oxygen.
Yes, several marine mammals such as whales, dolphins, and sea lions have specially adapted nostrils, called blowholes, that can completely close underwater to prevent the entry of liquid.
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