Do Whales Have Gills?

No, whales don’t have gills; instead they are born with blowholes.

Gills are actually a common feature of fish and many other amphibious species, however they are not present in whales or any of the cetacean species (whales, dolphin & porpoises) for that matter.

Gills allow many aquatic creatures to extract oxygen directly from the water so that they can breathe underneath the water without having to come to the surface.

Some amphibious species even have specially developed organs/skin that allows them to breathe above the surface of the water in addition to breathing underwater, as long as they are kept in a moist environment in order to prevent dehydration and assist with breathing.

A few some amphibious species can even survive for 6 months or more in moist environments.

For the most part however, most species of fish can only survive for a few minutes to a few hours above the surface without water.

Whales on the other hand cannot breathe underwater and have to come to the surface to breathe otherwise they would drown.

Whales are marine mammals and like all mammals they have lungs and nostrils, and are incapable of extracting oxygen directly from the water.

They breathe by surfacing above the water and inhaling air through their blowhole.

When you see water spout from the top of a whales blowhole it is actually a sign that the whale is exhaling.

Unlike humans whales however are unable to breathe through their mouth because their trachea (the pipe that goes to the lungs) and esophagus (the tube that goes to the stomach) are not connected.

This allows whales to surface partially above the water (exposing their blowhole) while keeping the rest of their body submerged underneath the water.

It also helps them breathe during states of rest where they may be seen logging (resting motionless) around the surface of the water in a semi-sleeping state.

Most importantly is the fact that whales can consume food underwater without exposing their lungs to possible water, which could lead to drowning.

To give you a better understanding of the differences between whales and fish/amphibians here are some bullet points describing the unique characteristics of these animals:

Whales

  • Are warm-blooded marine mammals
  • Breathe air (they get their oxygen above the surface of the water)
  • Give birth to live young (they have a gestation period similar to the pregnancy period of humans)
  • Produce milk to feed their young (female whales nurse and feed their young during the first several years of their life)
  • Have hair (some species of whale are born with hair that falls off shortly after birth)

Fish and Amphibians

  • Are mostly cold-blooded animals (they rely on external heat rather than produce their own internal heat)
  • Use gills, specialized organs or skin to breathe (some amphibians and all fish breathe underwater)
  • Lay eggs (most fish and amphibians lay eggs externally, however there are species that hold their eggs internally)

Note: Sharks are also classified as fish, however differences in their physiology (such as their cartilaginous skeleton) put these animals in a different category.

Will whales ever develop gills?

It is very unlikely that whales will develop gills, at least not for a very long time.

In fact it takes millions of years for an animal to evolve and change, so it is very unlikely that these changes would occur any time soon, and if they were to occur evolution would decide whether or not whales would develop gills or another way of breathing.

To give you a better understanding of the way evolution works let’s take a look at the oldest ancestors of whales.

Whales or rather their ancestors first existed over 50 million years ago as a land dwelling creatures.

These animals walked, hunted and lived on land and over the course of 50 million years whales slowly evolved from land dwelling creatures to the oceanic marine mammals we now know today.

In fact bones that were once used for walking and moving on land can still be seen in the flippers of whales and in the way they arch their backs when they swim.

Although whales moved from land dwelling creatures to ocean bearing animals they still require the same oxygen to breathe as their ancestors once did millions years ago, therefore whales possess lungs to enable them to take in oxygen when they are above the surface of the water.

When a whale comes to the surface of the water it exhales old air, which often appears as a cloud or stream of water shooting out from the whales blowhole.

While there is a common misconception that whales are exhaling water that they consumed it is actually oxygen that they’re exhaling from their blowhole.

The water that shoots up in the air is simply surrounding water that has been collected around the outside of the whales blowhole.

If a whale were to ingest water through its blowhole the whales lungs would fill up with water and it would likely drown.

This can sometimes happen when a whale is stuck on land during high tide.

In some instances the whale cannot move because it is too heavy to swim off land and the excessive high water ends up covering the whales blowhole until it can no longer hold its breath.

Aside from breathing oxygen whales are also warm-blooded creatures, which means they require blubber /fat to keep their body warm when they are in cold environments.

Without adequate blubber the whale could freeze to death or suffer internal organ damage in cold waters.

As stated earlier in order for a whale to grow gills it would take many millions of years of evolution and physiological changes in order to adapt from a marine mammal into a fish like species, which is cold-blooded and breathes through its gills rather than through lungs.

By being a cold-blooded species fish are able to adapt to various climate changes without the need for body fat.

Since they are cold-blooded they are also able to consume fewer calories than warm-blooded animals, which use the additional calories to form body fat and create heat.

Another distinction between whales and fish is the fact that whales give birth to their young in much the same way a land mammal gives birth to its young.

Most fish on the other hand lay eggs, which they either carry on their body or release into the ocean forcing their young to hatch and survive on its own.

As you can see from the various differences between whales and fish there is a lot of evolution that would have to occur in order for a whale to acquire gills, become fully compatible with surviving in cold water, adapt to new ways to bear offspring and having the ability to extract oxygen from the water they inhibit.

Evolution would have to decide whether its worth making all of these changes in order to provide whales with gills and adapt them to a fully aquatic underwater existence.

Whether or not whales will ever be able to grow gills and breathe underwater is a mystery that won’t be discovered for many millions of years.