Sharks have lurked in Earth's oceans for over 450 million years. Throughout these years sharks have transformed into the great hunters of the ocean we know now. Sharks have not always been ferocious predators, at the beginning of time they were merely a small part of the ocean food chain. Scientist have found it extremely difficult to study sharks do to the rapid decay of cartilage in salt water. Fossils of prehistoric sharks have been found on rocks collected from the ocean floor. Evolution is clearly found in sharks, making the prehistoric sharks almost unrecognizable compared to the predators we see today.
250 million years ago, life on Earth was flourishing. Suddenly, what came to be known as the “Great Dying” occurred, wiping out roughly nine in 10 marine species and seven in 10 land species. Plants, insects, microbes, proto-mammals, and fish completely wiped out. While the cause is of the event is still unknown, life on earth had come to an end. Nevertheless, sharks survived the mass extinction, by diving deeper into the vast ocean. With hundreds of marine species extinct and new territory sharks were forced to adapt to new surroundings. Sharks preyed on prehistoric squids and small fish, but with their jaws fused to their head the sharks prey was
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The Cladoselache is almost unrecognizable as a shark compared to todays sharks. This shark had its jaw fused to its head making it impossible to thrust its jaw and make it large enough to eat large prey. The Cladoselache also had smooth skin, they lacked dermal denticles leaving them almost naked. Dermal denticles are the tooth like scales found on modern sharks; they not only protect sharks from injury but they decrease drag in the water and increase the attachment to the swimming muscles. It wasn't until 200 million years ago sharks started to show a jaw that could unhinge and allowing the sharks to grow
Sharks have also been subjected to medical research, games and competitions, jewellery, souvenirs and cosmetics. We need to take into consideration that sharks play a vital role in the natural world that we live in. it is imperative that we look after these majestic creatures and ensure they remain protected. We need to be aware of the dangers of sharks, swim in protected areas where there are shark nets, and do not swim after dark in the sea (especially not alone) as the sea is the sharks home. Humans should also be wearing wet suits as protection in the ocean. The sea is where they live, they swim freely and they eat – they do not particularly target humans but rather prey on food that is available to them in their habitat.
As Stephen Covey once declared, “Just as we develop our physical muscles through overcoming opposition- such as lifting weight- we develop our character muscles by overcoming challenges and adversity.” This may seem like no sweat, but in reality it is laborious to do. Nevertheless, there are many people who embody this quote in our everyday lives and even in literature. The short story The Truth About Sharks by Joan Bauer, depicts such a person. In this anecdote, the experience that the protagonist, Beth faced, taught her to stand up for herself and therefore feel empowered. She went from a sullen teenager who was unable to stand up to her uncle and one who felt insecure in the shadow of her cousin, to someone with the confidence to rise above. The Truth About Sharks portrays a vital change that happened to Beth as a result of her being falsely accused of shoplifting and the challenges she faced to clear her name. This article renders a dynamic change that occurred in the main character, Beth who demonstrated the theme stand up for what you think is right.
The bull shark may be responsible for many shark attacks in the world but I believe that we have no right to kill them. Sharks are very important to animals food cycles and if the food cycles get messed up it can greatly effect the world. In fact, the bull shark is more vulnerable to human impact due to their ability to live in fresh and salt water but many sharks that are killed are for either shark fin soup or their liver oil. The sharks liver oil has many uses now but it started as a machine lubricant. Another way that sharks die is by recreational fishing. The sharks can get caught up in the fishermen's nets and eventually suffocate and die. As an environmental community, I feel like we need to inform people about shark habits and how to keep sharks safe. The water is their home and we are
This image is what a majority of people believe to be the shark. They believe it to be the bloodthirsty sea monster that appears in countless works of literature and films, but science says otherwise. The classic picture painted by the minds of sailors returning from years at sea come from imagination and sharks’ violent methods of hunting and mating. Sharks fear humans as much as humans fear sharks, and most sharks, particularly the “man-eating” great whites, only bite humans because they mistake surfers for seals. In earlier times, the ocean was a source of mystery and adventur...
...heir vision is not needed at that depth in the dark water (I 77). These parasites might actually help the sharks. These parasites are biolumiscent and they might attract those fast swimming fish to the oral side of the shark. With out these parasites it is possible that the sharks could not catch as many fish as it does, due to its slow speed. On top of the parasites on its eyes, the Greenland shark also has poisonous flesh. To get rid of the poison n order to eat it, the flesh must be boiled and dried several times (II 63). If the meat is not prepared correctly, it can cause, nausea, vomiting, diarrhea, and abdominal pain, tingling and burning sensation of tongue, throat and esophagus. It can also cause muscular cramps, respiratory distress, coma and death (III Vol 25, 905). This shark may not kill you when it’s alive, but you have to careful when it’s dead.
You may think a great white shark is massive, but their ancestors would make them look like midgets in comparison. An ancient shark called Megalodon appeared on earth more than 20 million years ago. Based on fossils of their teeth, scientists are estimating that the Megalodon would be the size of a school bus! That’s big enough to feast on whales.
Mojetta wrote about prehistoric sharks, and the history of these creatures. According to Angelo Mojetta, author of Sharks, Cladoselache genus, one of the first prehistoric sharks, was buried in sediment that kept it preserved. Unlike other sharks, Cladoselache genus had a circle of tiny plates around it’s eyes for protection against it’s victim’s attempts to fight back. These sharks lived over 400 million years ago. Sharks of the past could mostly be identified by their teeth, because shark’s bodies are made of cartilage. Another shark that was focused on was called, Stethacanthus. This shark had a very unique look. Stethacanthus had a brush like decoration on the top of it’s head, and an extra fin like part that had the same bristle like decorations on it. These characteristics were thought to be used as suction cups, to hitch rides from larger fish. One of the most famous sharks that looks like an over...
Sharks are known for their ability to kill and their teeth, but what people don’t pay much attention to, is their skin. A shark’s skin has, “sleek scales that resemble tiny teeth and are made of a tough material called dentin” (Lewis, Tanya. “Biomimetics: 7 clever technologies inspired by nature.” Live Science. Purch. 22 Apr. 2013. Web). Not only is the skin durable, but it contains hundreds of tiny teeth throughout the skin that acts
Every year, there are about 100 million Sharks killed, ultimately for its commercial success. Their fins are used as the main ingredient for a dish so-called Shark soup. However, many are unaware of the actual importance of Sharks' existence on Earth. They do a number of things to control and balance aquatic life down below, which in return affects how we live on the surface. Sharks have existed in our world for over 400 million years, if they were to suddenly disappear for industrial purposes, much problems will be encountered throughout the world. We must preserve the lives of Sharks, for many reasons most importantly that shark hunting is morally wrong, it may provide economic failure in a given time, and it may serve a critical unbalance of a healthy environmental state.
In 2015 only 59 shark attacks have occurred around the world compared to the millions of sharks killed by humans every year. Due to these accidental shark attacks people tend to think that sharks, especially Great Whites are evil creatures with malice intentions when attacks do occur; but, on the contrary that is wrong. Sharks are not the only beautiful and unique creatures in the ocean, they also play a vital role in our ecosystem; however, due to human interference they might not be around much longer, through awareness sharks can be protected from endangerment.
Thesis: Sharks should be conserved because they are an important part of the ocean, attacks are often incidental, and human behavior influences the behavior of sharks.
Most people think that sharks are large, fast-swimmers, and savage predators. This is true of some species and groups should be interested of the appealing aspects of biology found within it: all sharks have an excellent sense of smell; some can detect electrical discharges; some sharks give birth to one of the
The morphology of whale sharks is mostly similar to aquatic fish species, but many specific traits help differentiate them from the rest. Whale sharks are the largest fish in the world and can reach a size of around 20 meters (Martins, C., and C. Knickle). This is often compared to the size of a school bus. The shark has a very large transverse mouth. They have 5 very large gill slits and have a larger first dorsal fin compared to the second one (Whale Shark). They have a distinctive spotted “checkerboard” pattern with stripes (Martins, C., and C. Knickle). It is not exactly known why they have this specific body marking. It is believed that the body markings act as a camouflage. The strange thing about whale sharks is that they have 300 rows of teeth that play no role in feeding (Martins, C., and C. Knickle).
Sharks are one of the most feared carnivores in the sea. There are 365 species of of sharks in the sea as we know today. All sharks are carnivores. Most of them eat live fish, including other sharks. A shark's most common natural enemy is an another shark. Most sharks eat their prey whole, or they tear off large chunks of the bodies. Some sharks crush their prey. Others take out small pieces off flesh from large fish. Sharks also feed on dead or dying animals. Sharks have the reputation of attacking human beings. But less than 100 shark attacks a year are reported throughout the world. Sharks are most common in warm seas and oceans. Whale sharks, are the largest shark known to man. Sharks are classified in the order Selachii, which belongs to a larger class of fish called Elasmobranchi. The earliest shark-like vertebrate fossils are from the Devonian Period of the Paleozoic Era.
One particularly interesting sea creature is the whale shark, formally known as Rhincondon typus it was first discovered in 1828 by Andrew Smith (Rowat 2012). This large fish is found globally in warm tropical oceans and prefers to stay within 200 meters of the ocean’s surface in waters ranging from 4.2 to 28.7 degrees Celsius (Stevens 2006). This creature can be found all across the globe in any warm tropical seas. Aggregations of whale sharks have been seen off the coast of Australia at times, although it is primarily a creature of solitude. Whale sharks are filter feeders that consume plankton as well as small fish and are harmless to humans. The whale shark is a species with a fascinating ecology, life history, behavior, anatomy