INTRODUCTION Although sharks belong to the class Chondrichtyes, there are many different types. Sharks arose about 350 million years ago and have remained virtually unchanged for the past 70 million years and still comprise a dominant group. It is thought that sharks almost certainly evolved from placoderms, a group of primitive jawed fishes. It took a long series of successful and unsuccessful mutations with fin, jaw positions etc to give us all the different designs of sharks around today. When asked to draw a shark, most people would draw a shape along the lines of the whaler shark family, tigers or a mackeral shark such as a porbeagle. However many people do not realize the sheer diversity in the shape of sharks, or that rays are really sharks. Seldom does such an animal inspire such a variety of emotions reflecting a mixture of fascination, awe and fear. Sharks have occasionally exacted a terrible price from humans who have trespassed on their territory. No better understood than the ocean that they inhabit, these creatures should be regarded in the same way as lions, tigers, and bears: as dangerous, predatory but nonetheless magnificent animals. Different Types of Sharks Living sharks are divided into eight major orders, each easily recognizable by certain external characteristics. Each order contains one or more smaller groups, or families. In all there are 30 families of sharks and they contain the 350 or more different kinds or species of sharks. The eight major orders of sharks include the Squantiformes, Pristiophormes, Squaliformes, Hexanchiformes, Carcharhiniformes, Lamniformes, Orectolobiformes, and the Heterodotiformes. The orders have distinguishing characteristics that fit in each. The Squantiformes normally have flat bodies that are ray-like with mottled dorsal surfaces. These sharks have a short terminal mouth, which is armed with small impaling teeth. They also have a caudal fin, which has a lower lobe that is longer than the upper lobe. Their pectoral fins extend forward over the ventrally directed gills. The Pristiophormes have more of an elongated snout, which is saw-like and edged with slender, needle-sharp lateral teeth. They have two dorsal fins and no anal fin. They use short transverse mouths and small cuspidate holding teeth in both jaws. Squaliformes have no anal fin as well, but their snout is not elongated, but is somewhat long. Many have powerful cutting teeth in both jaws. In some species these razor sharp teeth are in the lower jaw only and the upper teeth serve to hold the food.
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.
The Kingdom, Phylum, Class, Order, Family, Genus and species for the Bull Shark are as follows: Animalia, Chordata, Chondrichthyes, Carcharhiniformes, Carcharhinidae leucas (Simpfender & Burgess). The taxonomy of every living thing is different, so the classification of the Bull Shark is the one way worldwide to know exactly what animal is being referred to because one animal may have many different common names. Carcharhinus leucas is referred to by many different common names around the world for example the spanish it Tiburon Sarda, the french call it Requin Bouledogue, in Africa they refer to it as Van Rooyen's Shark, in Australia it is referred to as the Swan River Whaler, and that is only a few of the Bull Sharks many common names (Curtis).
head of a hammer. Their eyes and nostrils are at the ends of the hammer. There
All primates have essentially the same kinds of specialized mammalian teeth adapted to eating a wide variety of foods. Beginning at the front, each quadrant of the mouth has 2 incisors, 1 canine, and varying numbers of premolars and molars. The incisors are used like scissors for nipping off pieces of food. The pointed canines are for piercing and tearing. The premolars and molars, with their cusps, are used to grind and smash food. In platyrrhine species, there are 3 premolars and 2 or 3 molars. This results in a dental formula of 2.1.3.2 or 2.1.3.3. In contrast, all of the catarrhines have 2 premolars and 3 molars, making a dental formula of 2.1.2.3. The chimpanzee shown below is an Old World anthropoid species and, therefore, has a catarrhine dental formula.
The Carcharhinus leucas commonly called the "bull shark" is a very unique shark. The bull shark can live in both salt water and fresh water but is commonly found along the Mississippi River and around Nicaragua. The bull sharks has a very blunt rounded nose giving it a bullish type of appearance thus giving it the name bull shark. The sharks are a dark black to a light grey with a white underbelly. Bull sharks can grow to be about 350 cm long and weigh around 230 kilograms. Bull sharks also tend to have smaller eyes compared to many other sharks which indicates that the bull sharks have limited vision. The bull sharks have triangular teeth like the great white shark (one of the bull sharks cousins). The bulls teeth are heavily serrated and are about 1.5 inches long which makes it easy to tear apart the flesh of their prey.
Have you ever wondered what the scariest shark is? I know i have. Well the scariest looking shark i know is the basking shark. The basking shark has a huge mouth and will eat you if you mess with it. These animals don't have a regular nutrient cycle they just eat what they really can. There natural biome is .The habitat
The Balaenoptera Musculus, or the blue whale, is the largest animal in the world. Blue
When most people hear the word "shark", the image of a vicious killing machine pops into their head. They picture something out of the movie Jaws, where a massive Great White shark terrorizes an entire beach and eats dozens of people. However, this fictional story is nothing more than Hollywood entertainment. In the real world, the tables are turned. Humans are the ones who kill sharks, and not just by the dozens. It has been estimated that over 100 million sharks are killed every year by humans (http://www.iflscience.com). Some estimates claim that the actual number of sharks killed every year could be as high as 273 million (http://www.iflscience.com). In this research paper, I will inform you of the many ways that sharks are being killed,
On average they weigh 4,000-7,000 pounds and grow approximately 16-20 feet long ( Great white sharks 1). < commentary needed>Great Whites are the apex predator of the ocean containing 300 serrated teeth and highly-developed senses to hunt prey. Sharks have a great senses of smell, the Great White can smell a drop of blood thousand of miles away. They’re hearing is very powerful , being able to hear the vibrations of prey distances of about 800 ft away and find the exact location through ‘ear stone’( Great white 3). A shark 's sense of hearing truly shows their uniqueness as an apex predator. In addition to great hearing they’re known to have great sight by being able to see up to 50ft away and transition into seeing in light and dark. Additionally sharks have a lateral line on their back that reaches from the front to the back tail, allowing
Shark slaughter has led to shark populations being rapidly decimated all around the globe. Fishermen report that sharks are also getting smaller because they are not being given enough time to fully mature. Although there are other fish that are targeted more than sharks, they are not exactly affected by the kind of endangerment that sharks are currently experiencin...
Sharks appear to be very vicious creatures that will eat or kill anything in its path. People think that all sharks are harmful and deadly to humans. However, research shows that this statement is not true. Sharks can be trained and tamed. They are just like big, aquatic dogs. Only about 2 dozen types of sharks are potentially harmful to humans. Shark attacks are also much more uncommon than one may think. Despite their fearsome appearances, sharks are not as vicious as they look.
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
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...
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.
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).