These 9 facts about sharks will surprise you

When it comes to sharks, most people only imagine a dangerous and ruthless sea predator. However, scientists emphasize that these creatures are much more complex, intelligent, and interesting than people think. Having undergone evolution for millions of years, these sea creatures are considered one of the oldest vertebrate predators on Earth.

Sharks or their ancient ancestors survived five major mass extinctions in Earth's history, including the famous Permian-Triassic extinction that wiped out nearly 90 percent of marine organisms. Today, they are found in almost all parts of the oceans and have acquired amazing characteristics over hundreds of millions of years of evolution.

1. Sharks can distinguish simple mathematical calculations

According to research, sharks are not creatures that act only on instinct. They can distinguish between different sounds, geometric shapes, and colors. In one famous experiment, young grey bamboo sharks remembered information about shapes and optical illusions for nearly a year.

Scientists have also found that they can distinguish between numbers, such as the difference between three and five, or four and seven.

2. Some sharks "like" jazz music

In a study involving Port Jackson sharks living off the coast of Australia, they were trained to find food through music. When jazz music played, they swam to the correct location and were fed as a reward.

However, when classical music played, they were unable to establish the same connection. Scientists note that this shows sharks have a high learning ability.

3. Some sharks also have belly buttons

Not all sharks lay eggs. Some species, such as bull sharks and hammerhead sharks, develop their young inside the mother's womb. They are nourished through an umbilical cord, and after birth, a belly button mark remains on their abdomen for a certain period.

In other species, the eggs hatch inside the mother's body, and the young are born alive.

4. Sand tiger shark embryos eat each other before they are born

In sand tiger sharks, the struggle for life begins inside the mother's womb. Several embryos develop in the female shark's two uteri.

The strongest one eats the remaining embryos. This process is called "intrauterine cannibalism" in scientific literature. Then, the surviving embryo feeds on unfertilized eggs produced by the mother and is born much stronger.

5. Sharks also have permanent friends

Most people consider sharks to be solitary hunters. However, studies have shown that grey reef sharks move together with friends from the same group for up to four years.

Young lemon sharks also live in groups and learn from each other how to hunt and avoid danger. Pairs that travel thousands of kilometers together have also been observed among great white sharks.

6. Shark bodies are covered with tiny teeth

Shark skin is not made of ordinary scales, but of tiny tooth-like structures called denticles.

These structures reduce water resistance and help them swim faster. For this reason, in ancient Europe, shark skin was also used to polish musical instruments and furniture.

7. Sharks can even feel a human heartbeat

In addition to the five basic human senses, sharks have additional special sensory systems.

They sense vibrations in the water, pressure changes, electric fields, and even the Earth's magnetic field. Through special receptors located in their head, they can detect electrical impulses caused by the muscle activity of nearby animals, and even their heartbeats.

8. Sharks find their way in the ocean through magnetic fields

Experts state that the sharks' ability to sense magnetic fields allows them to travel thousands of kilometers without getting lost.

Because of this feature, they maintain an accurate direction even during long migrations.

9. Sharks are older than trees

The first fossil traces of the oldest ancestors of today's sharks date back 450 million years.

This is approximately 60 million years before the appearance of trees, 220 million years before dinosaurs, and 350 million years before the rings of Saturn.

Today, there are about 500 shark species on Earth. Scientists continue to discover new species. Experts believe that the oldest common ancestor of humans and sharks lived about 440 million years ago, which shows that the history of these two species is closely intertwined.