Whale Dorsal Fin: Why, Identification, Several Type Whales Dorsal Fins And Facts


Fins are an integral part of a fish’s life. These fins can appear in different forms and help fishes to navigate underwater. Dorsal fins are one such fin that is located on the top of a fish’s body.

Dorsal fins assist fishes in rolling, taking turns, and stopping underwater. Dorsal fins are composed of connecting tissues devoid of any bone or cartilage. We can categorize dorsal fins into six types:

  • Single
  • Pointed
  • Split
  • Spine Triangular
  • Trigger
  • Trailing

Along with fishes, dorsal fins are also common among whales. 

Whale Dorsal Fin
Image Credit: A whale dorsal fin from Pxhere

And in this article, we will shed light on whales’ dorsal fins and every other fact associated with them. By the end of this detailed post, you will have extensive insight into the subject.

That being said, remember that this post is for informational purposes only and does not contain any medical data. 

Do Whales Have Dorsal Fins?

When we talk about fish, we associate fins with their anatomy. And all fishes have this category of the fin. However, whales are not fishes, yet do they also have dorsal fins?

Despite being not categorized as fishes, most whales possess dorsal fins. However, this fin acts differently for different whales. Also, the shape and size of dorsal fins are different for different whale species. 

In some species of whales, these dorsal fins are so small that they do not serve any real purpose. However, in others, these fins help in activities like

  • Breaking and swimming through ice
  • Enhancing hydrodynamics
  • Eliminating excess heat, and so on.

Do all Whales have a dorsal fin?

The dorsal fin’s primary function is to support the whale and prevent it from tumbling into the water. But do all whales possess this feature?

Image Credit: Pilot whale dorsal fins from Picsels

It is not a requirement that all whale species have a dorsal fin. This anatomy section is absent in species such as right whales and narwhals. Blue whales and sperm whales, on the other hand, have smaller dorsal fins. The dorsal fin of beluga whales has been changed into the dorsal crest. However, killer whales have a huge and conspicuous dorsal fin.

Some of the whale species that possess the dorsal fin include the following:

  • Minke whale
  • Blue whale
  • Sperm whale
  • Fin whale
  • Sei whale

Why do Whales have dorsal fins?

In whales, the dorsal fin is one of the four fins (two pectoral, one caudal, and one dorsal). And this fin is located on the top of the whale’s body.

The primary purpose of the dorsal fin is to help whales remain stabilized underwater, especially when they roll and support them while taking sudden twists or turns. 

What whale does not have a dorsal fin?

Whether a whale will possess a dorsal fin highly depends on its habitat. Hence, ‌not all whales have this feature. 

Whale species like beluga, grey whale, and north specific right whale do not possess the dorsal fin. In the case of the grey whale, in place of the dorsal fin, they have knuckle-like bumps on the lower back. 

Dorsal fins aid in eliminating extra heat, but since belugas live in the arctic region, any such feature would hinder these whales. In addition, Belugas have a dorsal ridge, which provides stability in the water. 

Whale dorsal fin identification

Recognizing a whale just by seeing it may not be an option. However, whales have some specific recognizing markings, one of which is their dorsal fin.

The dorsal fin, if there, will be on the top backside of the whale. Following are some of the features that will help you identify whales with a dorsal fin:

  • Minke Whales, Fin Whales & Blue Whales: Curved dorsal fin, located on the back
  • Gray Whales, Belugas, Right Whales: No dorsal fin
  • Humpback Whales: Low and nub-like dorsal fin
  • Orcas: Tall dorsal fin
  • Baleen and Beaked Whales: Small dorsal fin, two-thirds along with the back

However, in some whales, this feature is missing and replaced by a hump or a dorsal ridge. Nonetheless, whales with a dorsal fin will be easily identifiable near the ocean surface.

Whale dorsal fin shapes?

After understanding that many whale species possess the dorsal fin, it is now time to explore the shape of the dorsal fin. 

Image Credit: Sperm whale dorsal fin from Piqsels
WhalesDorsal fin shape
Fin whaleRelatively larger, sickle-shaped fin located far back on the top of the body
Killer whaleTall and angular
Minke whaleCurved, far back on the top side of the body
Humpback whaleSmall, broad-based nubby fin
Sperm whaleTriangular or circular hump followed by knuckles 
Sei whaleErect and slender 
Blue whalePretty small relative to the body, the shape can be variable 
Baird’s beaked whaleSmall and triangular, located far back
Hubb’s beaked whaleSmall and triangular, located far back
Cuvier’s beaked whale Curved, like that of a dolphin 
False killer whale Curved and black 
Long-finned pilot whalesTowards the front of the body

Why do whales’ dorsal fins flop over?

A whale’s dorsal fin serves a crucial purpose in helping these creatures maneuver their movement underwater. However, sometimes we may find a curved dorsal fin in whales. But why so?

A flopped-over dorsal fin can be an indicator of several problems in whales. Especially those whales kept in captivity are found to have a flopped-over dorsal fin. Some of the potential factors that may cause such issues include age, stress, the scope of reduced swimming, thermoregulation, physical health issues, dehydration, food unavailability, etc. 

In this context, killer whales, or orcas, in captivity, are often found to have a curved dorsal fin. However, experts have also observed flopped-over or drooping dorsal fins in wild orcas. And they believe that more than external reasons, a curved dorsal fin might be because of the genetic makeup of the mammals. 

Experts are still investigating to learn the actual causes behind such issues.

Whale with a small dorsal fin?

Whales have four types of fins, including the dorsal fin. However, not all whales have the same dorsal fins, as some even have smaller dorsal fins.

Whale species with a small dorsal fin include

Whale with a large dorsal fin

The dorsal fin of whales varies in size and shape depending on their species. So let’s look at the whales that possess a large dorsal fin.

The largest dorsal fin could be found in male orcas that grow up to 6 feet. In addition to orcas, the following are some of the whale species that possess a large dorsal fin:

  • Fin whale
  • Sei whale 
  • Minke whale

Whale with stubby dorsal fins?

It becomes easy to identify a specific whale amid other aquatic species if you know which types of whales have which types of dorsal fins. That brings us to the question of which type of whale has a stubby dorsal fin?

Humpback whales have stubby dorsal fins. In addition, you will find some bumps between the dorsal fin and the tail. And it is the hump in front of their dorsal fin gave these mammals the name- humpback whales. When they rise and bend their backs in readiness for a dive, this hump is highlighted.

Whale dorsal fin in captivity

A whale watch is a common amusement that has become quite popular among tourists nowadays. However, does keeping whales in captivity affect their fins?

In captivity, whale fins, specifically the dorsal fin, tend to bend or collapse. Although the specific reason behind this problem is yet to be deciphered by marine experts, it is often thought that lack of movement, stress, etc., could affect their fins to collapse. 

In this regard, marine biologists have discovered that captive killer whales or orcas frequently suffer from collapsed fins. However, the bending of the dorsal fin could be the result of a permanent structural transformation in the fin’s elastin over time rather than any disease.

According to SeaWorld’s website, the bend in the dorsal fin of captive orcas is due to the increased time these species spend at the water surface, where their fin is not sustained by hydraulic pressure.

Whale dorsal fin collapse

Image Credit: A killer whale with collapsed dorsal fin from Pixfuel

Like sharks and dolphins, whales are also recognized by their dorsal fin. However, not all of them possess this feature—still, those who do sometimes face the issue of the collapsed fin.

The dorsal fin aids whales in underwater mobility. So, a collapsed dorsal fin is frequently the result of a lack of that scope. Experts believe that partial fin collapse is caused by stress, injury, aging, decreased collagen, and entanglement. Although it is less well-known, exposure to oil spills can often induce this condition in the wild.

The issue of a collapsed dorsal fin is mostly found in whales kept in captivity, especially killer whales. 

Do blue whales have dorsal fins?

Blue whales are the largest mammals to live on earth. These whales are fascinating, and one of the best ways to identify them is by their fins.

Blue whales possess the dorsal fin. First, however, we must remember that the dorsal fin in blue whales varies vastly from those in other whales in terms of size, shape, and color. 

The Blue whale dorsal fin

When it comes to the anatomy of whales, one of the common features to look at is their fins. The fins of whales allow them to navigate and maintain stability underwater.

The dorsal fin of a blue whale is quite tiny (compared to its larger body). Their dorsal fin is approximately 30 cm (1 foot) in length. Furthermore, their dorsal fin is triangular and largely located in the last quadrant of their upper body.

Whale shark dorsal fin

Although they are called whale sharks, these are sharks, not whales. Whale sharks are the world’s largest sharks, as well as fish. Do they, however, have a dorsal fin?

Whale sharks have two big, conspicuous dorsal fins that are grey or grey-black. Furthermore, their dorsal fins are positioned well back on the body, ending in a huge twin caudal fin. The shark’s dorsal fins become more triangular as it develops in size. An adult male whale shark can grow up to 8 meters long.

It’s worth noting that young whale sharks lack spots on their second dorsal fin, which could make it difficult to recognize them.

Minke whale dorsal fin

Minke whales are counted among smaller whales and are known to be highly inquisitive. So if you spot one, how are you going to identify them? 

Minke whales are distinguished by their tall, crescent dorsal fin, which runs about two-thirds of the way between their head and tail. In addition, their dorsal fin has a curving structure seen at the exact moment as the blow.

Killer Whale dorsal fin

Image Credit: KIller whale with a tall dorsal whale from Pxhere

Killer whales are a dolphin species and are also known as orcas. They are not whales. These mammals are notable for their dorsal fin and their unusual body color.

Among all the cetaceans, killer whales have the tallest dorsal fin. In addition, male killer whales have the tallest dorsal fin, roughly 6 feet long.

Killer whales have tall dorsal fins, but they are not comprised of bones; instead, they are made of collagen-based fibrous connective tissue.

What number of killer whales have collapsed dorsal fins?

Collapsed dorsal fins are a prevalent issue among killer whales. This can be observed in both wild and captive orcas.

According to Seaworld’s website, only about 1% of males in any wild orca group have a completely deflated dorsal fin. In addition, there has been no open ocean female orca seen with completely collapsed dorsal fins, and partial collapse is extremely rare. However, in captivity, this problem has been discovered in almost all male and female orcas.

Summary

As a result, we’ve compiled a comprehensive list of dorsal whale fins. We hope you enjoyed our post and learned something new about the subject. Whales’ dorsal fins are largely used for navigation and serve an important part in their underwater survival. So, the next time you see a whale, try to identify its dorsal fin to figure out what species it is.

Atrayee

I am Atrayee, I have extreme passion for the Animal Kingdom and I have written a large number of articles for animal behaviors. I am an Animal Lover by nature and own two Cats.
Exploring new things through learning and unlearning is something that intrigues me a lot. I spend my free time with my husband and two cats. I must say I get to learn a lot of wise things from them! You can catch me on LinkedIn - https://www.linkedin.com/in/atrayee-samaddar-06886567/

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