Sharks are very interesting animals. Because they’ve been on Earth for so long, they’ve developed into many different kinds of species. Every shark is unique, and they all have adapted differently to the habitats they live in. Because of that, all of the species can seem like they’re all different animals. Here’s more information about sharks that show how amazing they are as animals.
1. Sharks have been on Earth longer than dinosaurs. Scientists believe sharks have been around for more than 400 million years, which are based on teeth and scales found in fossils. This is long before dinosaurs were on Earth. Over time, the ocean’s top predators have evolved into over 400 species that come in different sizes and colors. They also have varying diets and behavior, which is amazing for an animal that many people believe is all the same.
2. It’s not likely that you’ll be attacked by a shark. Although sharks are known for their human attacks, humans are not their preferred food. Shark attacks have increased steadily since the 1900s but this might be the result of better recording and a rising human population. Shark attacks are still very rare and a beachgoer has a 1 in 11.5 million chance of being bitten. This means they’re more likely to be struck by lightning or die from drowning than from a shark attack. Even though shark attacks are seen in horror movies sharks bite people out of curiosity, defense, or confusion.
3. Humans are a threat to sharks. Humans are responsible for the drastic decrease in shark populations. This decrease occurs due to overfishing. 100 million sharks are killed each year and they’re mostly to supply expensive dishes. Fisheries that catch whole sharks often cut off the fins and dump them back into the ocean where they bleed out or drown. This is done to save space on the boat and avoid surpassing fishbone braids but it’s very deadly to the shark population. Many fisheries have outright banned shark fishing.
Another thing that often impacts sharks are rising water temperatures in coastal developments. They contribute to the shrinking shark populations because the coastal developments are destroying mangroves in coral reefs. These are places that are used for breeding, hunting and protecting young shark pups. A drop in numbers is bad for sharks, but it could also be bad for ocean health in general. Because they’re top predators of the ocean, they are critical for balancing the food web.
4. Sharks fall into a subclass of fish called elasmobranchii. Species in this subclass have skeletons made from cartilage and have five to seven gill slits on the side of their heads. Their teeth are in several series and different parts of their jaw is fused to make a low and upper jaw. They also don’t have swim bladders and they maintain buoyancy by having large livers rich in oil. They’re mostly marine animals, but there are several species that live in freshwater environments.
5. Some shark species enjoy being in groups and socializing. Many species of sharks are known to prefer to be social and living groups or small aggregations. This is what the lemon shark prefers. There are a few benefits of group living like enhanced communication, courtship, predatory behavior and protection. Group living and a preference for social interaction is important for the survival and success of young lemon sharks. Group living comes with a cost. Some of the costs include increased risk of disease, parasite transmission, and competition for resources.
Many sharks make groups based on size. Also, shark groups formed due to the desire to be social rather than an attraction to the same limited resources. Younger sharks are different. Sharks up to 1 years old have shown no preference for groups of matched or unmatched eyes. Some believe that it is beneficial for younger lemon sharks to associate with larger individuals because they have an easier time gathering prey and information. Whatever the case, the younger sharks seem to make groups without the consideration of size.
6. Sharks have complex mating rituals. Shark mating begins when the female shark releases chemicals in the water. These chemicals stimulate the interest of the male sharks. Some sharks like hammerheads and great white sharks have complex mating rituals that involve shows of strength and possibly dancing. All sharks practice by me the way to get the attention of the female. Female sharks usually have bite marks across their bodies after mating the least bites are not as ferocious as feeding bites. Female bull sharks, blue sharks and tiger sharks have all adapted to his mating ritual and have skin 2 to 3 times as thick as their male counterparts.
7. Sharks mate roughly. Once a mate has been selected, the Sharks will begin copulation. Sharks practice internal fertilization. Male sharks have reproductive organs called claspers and female sharks have an opening called a cloaca. Fertilization happens when a clasper is inserted into the cloaca and the sperm is injected into the female. Mating begins a male shark will mount a female shark while swimming beside or underneath them. The male shark will bite onto the female to hold themselves study during mating. This can be a difficult process with both sharks out than ending up with wounds.
Once mounted, the male inserts the clasper, which is held inside the cloaca with a hook until the sperm is released. Most species of shark only use one clasper, but species like the hammerhead sharks and requiem sharks tend to use only the right clasper. Only the spiny cat shark has ever been observed using both claspers. Once the sperm is injected, the sharks part ways. Usually fertilization happens immediately for some species like the small spotted catshark can hold the sperm inside of themselves for two years.
8. Sharks vary in size.
The pygmy ribbontail catshark is one of the world’s smallest sharks. Fully grown, they can be anywhere from 6 inches or 16 centimeters and 7 inches or 19 centimeters. The largest one ever found was even very small and it measured around 9.4 inches or 24 centimeters long. They’re found in the Indo- west Pacific in Tanzania, the Gulf of Aden, India, the Andaman Islands, Vietnam, and the Philippines. They’re usually found in mud and they’re bathydemersal, which means they’re found in water below 650 feet below sea level. Researchers believe that this shark grows relatively fast because the female lays large eggs.
Whale sharks are the largest fish species on Earth and they can grow more than 55 feet.They can live as long as 130 years field data suggests. They have very large mouths and are filter feeders which is a feeding mode that occurs in only three sharks on earth. They feed almost exclusively on plankton and small fishes which means they pose no threat to humans. They have mouths that contain over 300 rows of tiny teeth and 20 filter pads to filter their food. They inhabit all tropical and warm temperate seas. This is a shark that you likely won’t see often, but it’s a great size makes it an amazing sight.
9. There are many rare species of sharks that often aren’t seen by humans. The goblin shark is a rare species of deep-sea shark. It’s sometimes called a living fossil because it’s the only extant representative of a lineage of sharks that’s 125 million years old. This is a pink skinned animal that has a distinctive profile with an elongated flattened snout. Goblin sharks have been seen in small numbers and unintentionally caught by Deep Water Fisheries. Despite its rarity, the International Union of Conservation of Nature has assessed it as a species of “Least Concern” because of its wide distribution and low incidence of capture.
10. Sharks have many modes of reproduction. The four forms of reproduction in sharks is viviparity, oviparity, ovoviviparous, and asexual.
Viviparity is when the fertilized eggs are hatched inside the female’s uterus. This eventually leads to live birth. There are 3 different kinds of viviparity.
Oviparity is when animals lay their eggs with no embryonic development inside of the mother. This is the reproductive method of most fish, amphibians and reptiles. The traditional modes of reproduction include oviparity where either unfertilized oocytes or fertilized eggs are spawned.
Ovoviviparity is a mode of reproduction in animals when embryos that develop inside eggs remain in their mother’s body until they are ready to hatch. The embryos don’t have any placental connection with the mother and they usually receive their nourishment from a yolk sac.
Sharks reproducing asexually is extremely rare, but it’s not unheard of. It’s possible because beyond sexual reproduction there’s another way that certain species can asexually reproduce which is called parthenogenesis. This allows embryos to develop without being fertilized like they are in sexual reproduction.
11. Sharks have a unique way of swimming. Sharks don’t use a swim bladder, but they have to use the forward movement to control their body and keep them in a vertical position. Their tail is similar to a propeller and the shark uses it by swinging it back and forth to move forward. In a shark, this movement pushes the water around it. It seems similar to the way the fish use their fins and swim. This is the movement that creates lift.
Sharks have two sets of paired fins on the sides of their body. The general position of their fins parallel the main wings that are found on a plane. They move at different angles to change the property of water that moves around them. Their fins will move in the water so that there’s greater pressure below the fin than above it, which creates an upward lift. The fins can also be tilted down so there’s a greater pressure above the same them than below it and this pushes the shark’s body downwards.
The shark also has multiple dorsal fins and sometimes a vertical anal fin. These fins are what act as the stabilizer and they can help to start keeping its balance as it moves through water. It can also help your shark turn left and right by moving side to side. The fin arrangement gives them great maneuverability and they can cruise at high speeds, stop suddenly or make sharp turns in every direction. This is what makes them effective hunters. They can move quickly and with more control than most of their prey.
12. The fastest shark in the world is the shortfin mako shark. The Shortfin Mako Shark is the fastest shark in the world. They can swim at speed up to 60 miles per hour. They also have a streamlined body that is shaped like a torpedo. This minimizes drag that experiences as they swim through the water. It also has a tail that is designed for propulsion with powerful tools that help it be a strong swimmer. They also have another biological adaptation that helps them and it’s their endothermic body. The endothermic body can help regulate the warmth of its blood and its body temperature is usually higher than the surrounding water.
Now that you know a little more about sharks, you can understand why it’s so devastating that the species is suffering. Gaining knowledge about animals can help you see that the actions of humans need to change so that these species of sharks continue to grow and flourish.