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.
head of a hammer. Their eyes and nostrils are at the ends of the hammer. There
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.
The Swell Shark’s taxonomy is as follows: it is a member of the domain Eukarya, the kingdom Animalia, the phylum Chordata, the class Chondrichthyes, the order Carcharhiniformes, the family Scylorhinidae, and the genus Cephaloscyllium (IUCN Redlist.org).
In Chinese tradition, Shark fin soup is called as “a celebration soup”, which people eat it to celebrate in various occasions. Moreover, people also believed that shark fin consisted of diverse nutrition values which provide them virility, wealth, and power(Wolchover, 2011). These beliefs lead to the beginning of poaching for sharks, the top of food chain in the sea world. Surprisingly, although people are aware of the decreasing number of sharks since the old days, around hundred million of sharks are still hunted each year(Heltus, 2013), to be served on luxury tables surrounded by those believers in things that they do not even prove whether the belief is reliable. Therefore, in the generation that people are mostly educated, sharks should no longer have to be continuously killed for their fins.
According to Animal Planet, sharks, on average, kill ten humans per year, while humans kill eighty-eight to one hundred million sharks per year. Humans hunt sharks for their meat, internal organs, skin, and primarily for their fins in order to make products such as lubricants, make-up, and mainly shark fin soup. The growing Chinese economy has cause an increase in the demand for shark fin soup. Some species of sharks have reduced over 90% in population for a bowl of soup that has no scientifically proven nutritional value. The poaching of sharks as seen in the shark fin trade should cease because it causes a collapse of the marine ecosystem and endangers the shark species.
The great white shark is a very interesting animal. They get their names from their appearance. The great white shark is very big and has a blue stomach. The great white shark can be found in the pacific, Atlantic and Indian oceans. The number of great white sharks in the United States and in the world is unknown because it is too hard to keep track of all of them. They live in salt water and do not claim territories.
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 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.
The differences between these two species concerning appearance,diet,size and other important factors of the species lives are important to know in case of close encounter and need of survival. It is important to know what they look like so to know their special abilities so they will be easier to evade. Hammerhead sharks and bull sharks are very aggressive towards their prey and take over most oceans. These species are very important because if you want to study them for research,then you should know their normal personality traits for easier behavioral comparisons. The appearance and design of hammerhead and bull sharks are very different.
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
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).
Frogs are amphibians in the order Anura. The order Anura is broken down into 22 different families of frogs and toads. Although they belong to the same order, frogs and toads are different in a lot of ways. Some of the more distinct differences are their skin and where they live. Frogs usually have smooth moist skin and toads usually have dry watery looking skin. Frogs spend most of their lives in or near water and toads spend more time on land. Amphibian means "double life." Frogs and toads each have two parts to their lives: when they live on water and when they live land. A frog's life starts in the water when it is hatched from an egg as a tadpole. A tadpole looks very different from an adult frog. A tadpole has a tail, no limbs, and breathes through gills. After a while the tadpole goes through metamorphosis. During the change the frog grows limbs, the tail disappears, it uses lungs to breathe, and it doesn't have to live in water anymore. As a tadpole, the frog feeds mostly on vegetation. The tadpoles have a small rasping mouth suited especially for scraping algea from the bottom of ponds. Depending on the species, it can take a few weeks to a year or more for the tadpoles to become fully grown. Not all frogs hatch as tadpoles. Some species of frogs hatch as froglets. Froglets look just like adult frogs but are a lot smaller. Froglets don't go through a metamophosis. Most species that hatch as froglets are found in dry places. Frogs who live in dry places where rains are seasonal have to grow up quickly because a tadpole will die if their temporary pond dries up. Adult frogs can live in water or on land, but it always needs to be near water so its respiratory organs don't dry out.
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