Facts About Sharks – Part 2

Facts About Sharks - Part 2

Shark anatomy

 

Facts About Sharks – The head of a shark is cone-shaped and large. In contrast, they only have small eyes on the sides and their nostrils are on the top of the snout. A shark has an enormous number of spare teeth that are located on the inside of the jaw edge. This is also necessary because when they attack teeth are regularly broken and are immediately replaced by one of the spare teeth that appear in the rows behind the front teeth. This way, the sharks always have razor-sharp teeth. The shark gets oxygen from the water through its usually 5-gill slits. Sometimes there are 6 or 7-gill slits. These occur on both sides of its head. Many sharks have to move continuously to get oxygen.

 

The so-called skin teeth are on the shark’s skin. These are tilted backward and have the structure of sandpaper. The sharkskin was therefore effectively used for this. The whole forms a kind of armor that is useful when they are going to fight with prey. At the same time, parasites are much less likely to penetrate the shark. The cutaneous teeth are also called placoid scales. They are covered by dentin and on top of that with enamel which makes them extremely durable. If a skin tooth falls out, it is immediately replaced again, as with the common shark teeth.

Shark Teeth
Shark Teeth

In different sharks, the skin is also different and the shape of the skin teeth is also adjusted. For example, you have the blackberry shark where the skin teeth are knobby and the size of a shirt knot. The goblin shark, on the other hand, has long, thorny skin teeth that are the size of a pint on barbed wire. Most other sharks have very small skin teeth of just a few millimeters in size. Furthermore, the skin teeth differ according to where they occur on the body of the shark. They are rounded on the muzzle and contain nerve connections for the sense of touch. On the fins, they are like a kind of diamond with razor-sharp edges to easily cut through the water. And finally, the skins on their stomach serve as protection when the shark is resting on the bottom, for example. These skin teeth are flattened.

Goblin Shark
Goblin Shark
Blackberry Shark
Blackberry Shark

 

The camouflage-colored skin protects them from harm and also serves as an organ for touch and movement. Compared to humans, a shark’s skin is thicker than a finger in an adult human, and the whale shark’s skin can be as much as six inches.

There are paired or unpaired fins on the shark’s hull. Directly behind the gill slits are the paired pectoral fins. They then have the famous single dorsal fin on the center of their back. At the end of their body, there are still the pelvic fins, a second dorsal fin, and an anal fin. The sex organ in a male shark consists of a modified version of the pelvic fins.

Because sharks usually have a specific way of life, most species can be distinguished by their enormous caudal fin.

Unlike the common fish, sharks do not have a swim bladder. To float, they need a kind of oily substance from the liver, called squalene. In the pharmaceutical industry, this squalene would also be used because it would have an alleged rejuvenating effect. Various products are also made from sharkskin.

Sharkskin Rasp
Sharkskin Rasp
Oval Concave Mirror (c.1740-50), in sharkskin case
Oval Concave Mirror (c.1740-50), in sharkskin case
Set of money scales in sharkskin case (money scales; coin beamscale)
Set of money scales in sharkskin case (money scales; coin beam scale)

A shark is very fast and flexible in its movements and this is because its skeleton consists of cartilage to which the muscles are attached and is very flexible. The cartilage is a kind of elastic and flexible substance and is light, pearly colored. The other vertebrates only have some cartilage in a few places.

In fact, one can speak of only 2 types of skeletal muscle consisting of red or white tissues. Only 10% of the shark’s body is made up of red muscle tissue and is so-called because the muscles are continuously supplied with blood. This allows the shark to swim around for a long time and make small, smooth movements without getting exhausted. However, the white tissues receive less blood supply and are only optimally used in an attack where the shark has to respond quickly. That is why it happens that a shark suddenly has to stop the attack because its white muscles are “tired”.

Cartilage
Cartilage

Facts About Sharks – Body language of the shark

Most of us are of course afraid of the shark and want to run away as soon as possible. Still, some brave scientists have investigated the “imposing behavior” of various sharks. They felt a bit obligated to do it for all the people who are increasingly into water sports which can get very busy on the beaches. And as a result, of course, more people come into contact with sharks and accidents happen. Especially divers and snorkelers should learn how sharks behave and pay attention to their body language. After all, they are the most vulnerable.

If a shark suddenly swims to the bottom, it is a sign that the animal is uncomfortable. The zigzagging and the fast turns are also a sign of this. With such sightings, it is best to hide somewhere on the bottom or behind a rock or a cliff to break their normal feeding pattern. Especially when diving in open water, take a good look around you when descending or going up. Above all, be respectful, keep a safe distance, and don’t challenge them! Also, make sure you have a diving partner. And remember that you are 45,000 times more likely to die in a traffic accident than to be attacked by a shark. A shark is curious and if it feels comfortable it will even follow the diver as it descends. Then the animal certainly has no attack plans. Instead of “blackening” the sharks, realize that they are definitely not men-eaters. If you do feel threatened then you should calmly swim backward to keep an eye on the shark. Diving in the wilderness of the sea can be compared to participating in a safari. You never know which animal you will find in your path.

According to experts, the sharks do send out warning signals that humans are still unaware of. A shark that feels comfortable and relaxed will swim horizontally using only the caudal fin. If the animal arches its back and points its pectoral fins down, the shark is tense. A shark that is restless will also swim zig-zagging. This occurs in practically all sharks. Sometimes this behavior lasts differently in different sharks, short in some and longer in others. If you see this then it is better to get out of the side as soon as possible. Because if this is a white shark, you have at most 4 seconds … With a gray reef shark you get a margin of 40 seconds which is not reassuring. Sometimes the shark will only point its pectoral fins downwards but will keep swimming horizontally. However, this is also an omen for a possible attack. Personally, I would say to look at those pectoral fins first and foremost. Some sharks show their flanks for a long time and then suddenly turn sideways to slowly swim past their target. A white shark will then bare its gigantic teeth making it look like it is smiling. Or is it a dangerous grin here? But make no mistake, get out of here! Sometimes such a shark comes at you very quickly and it shoots away at the last minute. If that isn’t terrifying?

The researchers could also see that the sharks only display such behavior when they feel threatened and not to protect their possible food supply. For example, one of the researchers was able to feed the sharks and remain at a certain distance so that the sharks behaved completely calmly because they did not feel threatened.

"Laughing" White Shark
“Laughing” White Shark

Facts About Sharks – The habitat of the shark

The marine ecosystem of which the shark is a part is the most extensive and oldest part of the natural habitats on Earth. This covers more than two-thirds of the world’s surface. You can also see this clearly on the globe.

Just as we have different regions on land with mountains, valleys, forests, etc., you also have various structures under the water surface. An ocean can for example consist of different biotopes. On the seabed, you will find the fauna and flora that live there. In open water, on the other hand, the topography can vary enormously. There are plains, sloping or steep slopes, cliffs, seamounts, or deep underwater troughs.

In the very highest layer to a depth of 100 meters, it is relatively clear and the sun can still breakthrough. Here are many algae that serve as food for all other organisms in the sea. Then comes the next layer from 100m to 1000m deep where you are in the twilight zone. This is where most fish, squid, and sharks are found. The sharks can even hunt each other in the twilight. If you then go even deeper it becomes pitch dark and there is enormous water pressure. There is little life here, but species are also discovered, including even an unknown shark.

There are even sharks that search very shallow water for food such as the reef sharks. They can be found especially in the coral reefs. Some people wade in a coral reef and are amazed when such an animal brushes their legs. And if it is really shallow, even the dorsal fin sticks out above the water.

Other sharks stay near steep slopes because the other hunting fish make their way back up in the twilight, usually swimming in schools. This, of course, makes them easy prey for a shark.

One of the most common sharks in shallow water is the tan nurse shark.

It was not until 1976 that a new shark was discovered when the animal was dragged by anchor by an American naval vessel at a depth of 140 meters. The specimen was completely new to science. Because the shark had a very large mouth it was called “megamouth” by the Americans.

Megamouth Shark
Megamouth Shark
Nurse Shark
Nurse Shark

Switch to Facts About Sharks (Part 1)

Some interesting links about sharks:

Finally

Hopefully, you have learned something about the facts about sharks. And keep in mind that these animals are really not as dangerous as we think. We would do better to give them full respect. If something is still unclear or you want to add something to the article yourself, please let me know. Thank you for reading.

Leave a Comment