Sharks are large fish popularly known as the apex predators in the sea world. The earliest fossils of sharks indicate that they existed even before dinosaurs. While you’ll mostly find them in deeper and darker regions of the oceans, a small number of shark species can also survive in freshwater lakes and rivers. That said, there’s no confirmation of the total number of sharks worldwide.
Also, the shark population is declining for two reasons: the hunting of sharks for consumption and the lack of water (ocean) conservation due to increased garbage dumping. In some regions of China, shark fin soup is considered a delicacy.
While it’s a fish, many misconstrue it as a mammal. While the majority of shark species give birth to young ones, a very small number of them lay eggs. The sharks typically have cold blood that matches the water temperature they swim in. Yes, you can find sharks even in the Arctic Sea. However, the great white shark manages partial warm blood in its body, which helps them while chasing their prey.
Sharks can smell blood even a quarter of a mile away—an excellent market for a predator. TV shows and movies portraying sharks as chasing and eating humans are unrealistic. That’s because sharks don’t eat humans. Like other animals and reptiles, they only attack when they feel threatened.
While sharks mostly eat fish, some also enjoy devouring sea lions, tuna, sea birds, seals, penguins, and seals. Despite such pop culture popularity, shark attack numbers are much lower than the recorded attack numbers of other animals.
Besides the smell of blood, sharks can identify potential prey based on sounds, vibrations, and visuals. They usually attack from behind the fish to gnaw off rear tail fins and slow them down. You may mistake the relatively smaller eyes of sharks as disadvantageous. However, most sharks have fantastic eyesight and can see colors. Their eyes also have night vision-like capabilities to help them navigate darker areas.
Sharks’ famous serrated teeth are ideal for seizing, cutting, and crushing prey. The gills in front of their fins take in water through tiny vessels and absorb oxygen to breathe underwater. They also have dark spots near their faces, which are like mini-organs. These spots help them sense shifts in temperature and nearby electromagnetic fields. The low-density liver oils help them remain buoyant easily underwater.
Like in varieties of fish, sharks’ skin feels different. On touching, it reminds you of sandpaper. However, its surface consists of tiny teeth-like structures that point towards its tail to help the shark swim faster.
One surprising fact about sharks is that they don’t have bones. However, they can still fossilize. Their skeletal cartilage strengthens with calcium deposits over time and is relatively lighter. However, their jaws have enamel and are heavier when dried. Scientists count the ring-like bands on the back of the sharks to estimate their age.
You can find sharks in different shapes and colors. Most of them have a shape like a torpedo, but some have flat bodies resembling a ray and live near the ocean floor. The dwarf lantern sharks are small enough to fit in an adult hand. Meanwhile, the whale shark can be long, almost like six people standing on each other. Also, each whale shark has different spots, just like each human has fingerprints that are unique from the others. Similarly, the hammerhead shark, aptly named, has a head shaped like a hammer.
Also, sharks have a very low reproductive rate and grow very slowly. Most sharks live as long as 20-30 years, but some of its species manage to outlive this number. Scientists claim that the Greenland sharks in the North Atlantic Ocean are one of the oldest shark species.
One fascinating fact about sharks is that they don’t sleep. Instead, they have active and resting periods to preserve their energy. However, they do this in deeper water. That said, the best way to prevent a shark attack is to avoid swimming into deep waters of the ocean at night.