Exploring the Cognitive and Sensory Capabilities of Sharks

Nowadays, humans have become so curious. We humans are conducting experiments on primitive algae and huge dinosaurs. We are always interested in discovering facts, unveiling truths, and learning the science behind everything. Everyone is aware of oceans. And what is famous in the oceans? Without a second thought, anyone from a kid to an adult would answer it with “Shark.” But the catch is, do sharks have brains? If they have, what is it like? Is it similar to humans? Will they be able to think with it?

All know that sharks are one of the scariest creatures that live in oceans, and they are famous for their strong jaws, keen teeth, and slender bodies.

So, in this article, we are discussing the topic that revolves around sharks and most importantly their brains.

1. Different Shark Species

How many different kinds of shark species do you think exist? You will be surprised to know that there are approximately 500 different species of sharks there living in the oceans. Different species of sharks have a brain of various sizes.

These different species of sharks are split into eight orders: Carcharhiniformes, Hexanchiformes, Hederodotiformes, Lamniformes, Pristiophoriformes, Squatiniformes, Orectolobiformes and Squaliformes.

Famous shark species include the Great White shark, Whale shark, Megamouth shark, Hammerhead shark, and Tiger shark. The Greenland shark is also one of the famous shark species found in the Atlantic Ocean.

2. Overview of Shark Brain

Sharks do have brains. But what makes it different is that the shark’s brain is a complex and highly evolved organ that facilitates these dangerous creatures’ travel to the vast ocean, finding prey, and reacting to environmental cues.

The shark brain comprises the central nervous system. It also contains the spinal cord. Many tasks like processing, understanding, and coordinating the body’s responses to information from the surroundings are done by the central nervous system.

Sharks have their brain inside their head, which are shielded by their skull. Shark brain anatomy has significant similarities to that of other vertebrates. However, there are several observable differences, too.

The most notable difference includes the size of the olfactory bulbs, which are helpful for the animal’s sense of smell. Sharks have extraordinarily big olfactory bulbs in comparison to those of other vertebrates.

The shark brain is further divided into several regions. The cerebrum and cerebellum are one of them. The cerebrum is important for processing information through the senses passed in the animal’s body and is also responsible for controlling voluntary movements. The latter is used for balance and to coordinate movements.

3. Evolution of Shark Brains

Most fish started to have cartilage 400 million years ago, although fish evolution is a complex part of history. Sharks also have cartilage. They have developed into one of the most powerful and effective ocean predators after surviving five massive catastrophic extinctions.

Sharks passed through many years of evolution till they acquired extremely specialized brains that can adapt to a vast kind of environment. 

Many scientists thought sharks’ cognitive abilities requirement for their complex behaviors has led to their enormous brains.

The real catch is that a shark’s brain is more similar to a bony fish, although they are mostly related to cartilaginous fish. However, a significant difference between a shark and bony fish is that the latter have relatively larger cerebellum. 

Sharks have smaller cerebellum because of their unique swimming style. They swim by employing their entire body which requires relatively less coordination than bony fish. So, this can be considered a notable evolution.

4. Do Sharks Have Brains Larger Than Other Animals?

Depending on the species, the size of a shark’s brain differs. But generally, sharks have brains comparatively smaller than mammals, which are equal in size. 

On the other hand, sharks have a highly specialized brain that has evolved to fit their particular habitat. We can explain this by taking the example of the sizable olfactory bulbs of sharks that process information about smell.

5. Do Sharks Have Brains Similar to Humans?

Some scientists discovered that there are significantly many similarities between the shark brain and the human brain. and many of them think that this discovery would facilitate the development of repellants for these dangerous beings.  Research said that sharks have a brain similar to humans.

As discussed above, sharks have cerebellum in their brains. This cerebellum in the shark’s brain controls motor movements. This is seen in the early sharks, which can be stated as an evolutionary development that provides them with higher neural functions similar to human beings.

6. Myths That are Usually Associated with Sharks

For many years, we all have had one or other misconceptions about sharks. Now, we will discuss some of the things that are usually heard.

6.1. Sharks Frequently Attack People and Sharks Eat People

The interesting fact is that only a dozen of 400 different shark species exist to prey on humans. Great white and tiger sharks can be a better example. But a shark usually consumes smaller fish and invertebrates. While some shark species can be dangerous to humans, unprovoked attacks are uncommon.

Looking into the statistics, on average, sharks attack 70 people a year. Of that 70, only six of them are reported to be killed. Considering an example, in the year 2017, in a total of 88 unprovoked shark attacks, only five were particularly fatal.

The reason for a shark attack is simple. When the sharks are intrigued or perplexed about why a person is in their locality (here, water), they tend to attack but not kill. 

6.2. Sharks are Dumb Having a Smaller Brain

Previously, we have already discussed that sharks have a brain that is vast enough. You will be shocked to know that a shark’s brain can weigh around 1.2 ounces. The great white’s brain is especially two feet long. 

6.3. Sharks Move All the Time to Keep Them Alive

It’s a universal truth that sharks breathe through their gills. It’s no surprise that they acquire oxygen when water is passed through their gills. But it isn’t necessary for them to move all the time to make this happen. However, some species of sharks need to move. But most of them don’t.

The ancient sharks used a technique called buccal pumping to breathe. This process involves bringing the water into the mouth and over the gills.

6.4. Cancer is no Harm for Sharks

Despite the discussions that sharks don’t suffer from cancer. They do catch the disease.

As previously mentioned, sharks have cartilage. Sometimes, this cartilage could stop the growth of tissues from blood vessels. This is an important symptom of malignant tumors.

6.5. Do Every Shark Look the Same

Whenever we hear about sharks, the great white shark strikes our mind immediately. But first of all, you should know that sharks are found in different shapes, sizes, and structures. There are many kinds of shark species.

Whale sharks are one of the largest fish species in the entire world, and they can grow up to 40 feet long. Great white sharks can reach around 15 to 20 feet long.

Are all sharks huge? No. Here comes the lantern shark, which is so small that it can easily fit into a human’s hands.

7. Sensory Systems in Sharks

In the process of evolution, sharks have developed a highly specialized sensory system that allows them to comprehend and adjust to unique environments.

These senses assist them in avoiding danger from predators by locating them in their environments. 

Sharks have exceptional vision, smell, electroreception, hearing, touch, and other senses.

7.1. Vision

Having already discussed sharks have a highly developed sensory system, sharks have excellent vision and the ability to see even when there is limited light. Their vision helps them to navigate their prey in a dim environment, too.

This is because they have a specialized retina composed of rod cells in a high concentration. These are responsible for the shark’s ability to detect light levels.

Behind this retina, sharks have a reflective layer which is tapetum lucidum which helps them to see in low light conditions. Despite having these specifications, however, shark’s vision is comparatively low when compared to human’s vision.

7.2. Smell

Sharks can identify their prey even if they are far away by using their remarkable sense of smell. Their olfactory system is highly developed, having a pair of olfactory bulbs on the front portion of their 

Olfactory nerves are responsible for the ability of the shark to smell.

These olfactory nerves connect olfactory bulbs to nostrils. Haven’t you wondered how a shark can sense a single drop of blood in a million drops of water? Sharks should thank their excellent olfactory system.

7.3. Electroreception

This is one of the unique senses that sharks have which is responsible for detecting electrical fields which are transmitted by other animals.

A shark can do this because they have some specialized pores on their head and snout which are called ampullae of Lorenzini which help them in detecting electrical fields. The information is then forwarded to the brain by the neurons connected to the brain.

7.4. Hearing

You might be surprised to know that sharks have a highly developed inner ear, which makes them detect sound in large oceans. They can detect movements in the water because they have a membranous labyrinth where a network of sensory epithelia and structures are linked to it.

The great white shark has a unique structure which is macula neglecta. This macula neglect is responsible for detecting sounds that are of low frequency.

7.5. Touch

Sharks are known for having a sensitive touch. This sense of touch is responsible for detecting any vibrations in the water. The lateral line, which is over the length of their body, consists of a network of sensory cells making sharks detect changes in the water pressure, which plays an important role in detecting the movement of their prey.

8. Role of Spinal Cord in Shark Nervous System

We are aware that sharks have a brain and spinal cord that consists of their central nervous system. This spinal cord connects the brain to other parts of its body. 

The spinal cord transmits motor signals from the brain to muscles and also sensory information from the body to the brain. 

A shark has high levels of reflexes, which provide it with quicker turns and the ability to bite prey efficiently. This is carried out with the help of their spinal cord.

9. Medulla Oblongata in Shark’s Brain

The medulla oblongata in a shark supervises the majority of its vital activities. It’s quite interesting that this medulla oblongata is responsible for controlling the blood pressure of the shark and it also carries out the respiration process of the shark.

Apart from the abovementioned, the major role of medulla oblongata is to control the body temperature and preserve the ideal equilibrium of a shark.

10. Concluding the Topic

From this article, we can discover many facts about sharks. Till now we believed sharks to the dangerous killers. This article showed the real side of a shark.

A shark’s brain is a very complex and highly developed organ of a shark which helps it to survive. Significant components of Shark brains are the central nervous system along with the spinal cord. This central nervous system is responsible for processing, understanding, and coordinating the body’s responses. 

Also, there are many sharks found in oceans. Sharks have a brain that is usually bigger than other fishes. But this might differ from species to species of sharks. When mammals come into play, shark brain is comparatively of lesser size than mammals.

There are many myths associated with sharks. Most of the population thinks sharks are mindless eating machines, and they are used to attack humans. But it isn’t true. There is no such evidence proving shark attacks. But some species of shark do kill humans.

Sharks have developed an extraordinary sensory system. They have senses like vision, hearing, electroreception, touch, and smell. Using these senses, sharks track prey, hide from danger, and survive in the dark. 

Last Updated on May 4, 2024 by Arnab