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Do Whales Have Gills?

humpback whale

Have you ever wondered how whales breathe? You may have heard they have gills like fish, but is that true? In this article, we will explore whether or not whales have gills and how they actually breathe.

Do Whales Have Gills

Whales do not have gills as they are mammals. They breathe air through their lungs, not gills.

Whales have evolved to live in water but still need to breathe air to survive. They have adapted to this by developing a blowhole on the top of their head, which they use to take in air when they surface.

The blowhole is connected to the trachea and lungs, which allows the whale to breathe in air and expel carbon dioxide. When a whale surfaces, it exhales forcefully through its blowhole, expelling a spout of air and water vapour.

Gills vs Lungs

blowhole of a humpback whale
Blowhole of a humpback whale.

When it comes to breathing, whales and other marine mammals are different from fish and other aquatic creatures. Fish have gills, which extract oxygen from water, while whales have lungs, just like humans.

Whales breathe air through their blowholes, which are located on the top of their heads. When they surface, they exhale forcefully through the blowholes, expelling a spout of warm, moist air that condenses upon contact with the cooler outside air. This is what people refer to as a whale’s “blow”.

Unlike fish, which can extract oxygen from water, whales need to surface to breathe. They cannot extract oxygen from water, and their lungs would fill up with water if they tried. This is why whales have evolved to have large lungs that are adapted for efficient gas exchange.

Whales have two types of breathing: voluntary and involuntary. Voluntary breathing is when a whale consciously decides to take a breath. Involuntary breathing is when the whale’s brain automatically triggers the breathing process, usually when the whale is asleep or diving.

How Long Can a Whale Hold Its Breath?

The answer varies depending on the species of whale. Some whales can only hold their breath for a few minutes before resurfacing for air, while others can hold their breath for up to 90 minutes or more. For example, the sperm whale can spend around 80 to 90 minutes underwater before it has to come back up to breathe.

The beaked whale can remain submerged for as long as two hours. The longest recorded time that a whale has held its breath was 222 minutes, set by a Cuvier’s beaked whale.

So, how do whales manage to hold their breath for so long? Rather than keeping oxygen in their lungs. Whales’ bodies have adapted to store oxygen in their blood and muscles. They have extraordinarily high levels of the oxygen-storing proteins haemoglobin and myoglobin.

In addition to their high levels of oxygen-storing proteins, whales have other adaptations that allow them to stay underwater for extended periods. They can slow their heart rate and reduce blood flow to non-essential organs, directing more oxygen to the brain and other vital organs.

Do Whales Ever Inhale Water

The answer is yes, whales can inhale water, but it’s not common. When a whale surfaces to breathe, it exhales air from its lungs, creating a spout of water and air. Sometimes, the whale can accidentally inhale water along with the air, especially if it’s in a hurry or under stress. Whales have a unique mechanism that helps them avoid inhaling water.

Whales have a flap of tissue called the epiglottis that covers their blowhole when they’re underwater. The epiglottis acts like a valve, preventing water from entering the whale’s respiratory system. When the whale surfaces to breathe, the epiglottis opens, allowing air to flow into the lungs and the spent air to be expelled.

There are some situations where a whale might inhale water, such as when it’s sick, injured, or under stress. For example, if a whale is caught in a fishing net or stranded on the beach, it can inhale water as it struggles to breathe. In these cases, getting help for the whale as soon as possible is important.

Why Didn’t Whales Evolve Gills

killer whale jumping out of the water.

Whales are highly adapted to living in water, but they do not have gills. Instead, they breathe air through the blowholes on the top of their heads. This raises the question: Why didn’t whales evolve gills?

You need to understand that whales evolved from land mammals. Their ancestors were four-legged creatures that lived on land and breathed air through their lungs. As they evolved and adapted to living in water, they developed several features that allowed them to survive in the aquatic environment.

One of the key adaptations was the development of a streamlined body shape, which reduced drag and allowed them to move through the water more efficiently. This, in turn, allowed them to conserve energy and swim for longer periods. They also develop a thick layer of fat, which provides insulation and helps them to regulate their body temperature in cold water.

The evolution of gills would have required significant restructuring of their respiratory and cardiovascular systems. This would have required multiple mutations to occur simultaneously, which is highly unlikely.

Even if these mutations did occur, there would be no obvious advantage for whales to have gills. They are already highly adapted to living in water with their current respiratory system, and gills may not provide any significant benefits.

The evolution of gills is a complex process requiring a lot of energy and resources. It is possible that the energy required to evolve gills would be better spent on other adaptations that are more beneficial for survival in the aquatic environment.

While it may seem logical for whales to have evolved gills, several factors make this unlikely. Their current respiratory system is highly adapted to life in water, and the evolution of gills would require multiple mutations and a significant amount of energy and resources. Therefore, it is unlikely that whales will ever evolve gills in the future.