All animals under go a process of constant change in their physical appearance and in their behaviour. These changes take place over millions of years and the species that survive, do so because throughout their evolution they have perfected certain strategies that have enabled them to develop more successfully in the environment they inhabit. One such case of this successful development is the great hammerhead shark.
The great hammerhead shark, also known as Sphyrna mokarran, is a pelagic shark and is found world wide in tropical warm water regions. Great hammerheads are the largest species of hammerhead shark. The great hammerhead can be distinguished from other hammerheads by the shape of its “hammer” (called the “cephalofoil”), which is wide an almost straight front margin, and by its tall, sickle-shaped first dorsal fin. (Wikipedia, 2014)
The function of the hammer is widely unknown but many theories have been put forward as to its purpose. The most popular are that it helps the great hammerhead to scan larger areas of the ocean floor for food, and it maximises the area of sensory organs known as the ampullae of Lorenzini that can detect chemical, physical and thermal changes in the water, as well as electric fields. (MarineBio.org, 2014)
The body of the great hammerhead is the biggest of the nine species of hammerhead sharks and is coloured grey-brown to olive green on top and off-white below. They have heavily serrated triangular teeth. The length of the great hammerhead can range from four to six meters and weigh between 230 to 450 kg.
The great hammerheads have spectacular vision with their eyes positioned at either end of its widely shaped head. The positioning of the eyes give the hammerhead a panoramic vision and a be...
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...er. like most pelagic sharks, the hammerhead need to keep moving not just to stay away from the bottom but also to help it breath. if a hammerhead stops swimming it will drown. the hammerheads flat head acts as a wing to keep it from the bottom.
The great hammerheads are not known to be territorial but they are instinctively going to do what they can to protect their needs.
One of the major threats to great hammerheads is due to the fishing industry. The hammerhead is prized for its fin for shark fin soup, as well as for its liver oil for vitamins, its skin for leather, and its meat for fishmeal. Catastrophic losses have occurred in the eastern Atlantic where directed fishing is unregulated.
Conclusion:
The great hammerhead is endangered due to human interaction and not due to the fault of their strategies. Their strategies didn't incorporate human interaction.
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...
head of a hammer. Their eyes and nostrils are at the ends of the hammer. There
The appearance and design of hammerhead and bull sharks are very different.When you are looking at a picture of a hammerhead shark,the first thing that always grab your attention is the shark`s head.Some people may be wondering why the hammerhead shark has an unusual shaped head.’’The strange-looking head of the hammerhead shark (family Sphyrnidae) gives them increased maneuverability for catching agile prey such as squid and may also improve their sensory capabilities(‘’Sharks,Rays & Chimaeras’’ 64).According to the quote,the hammerhead shark`s head is shaped to give it increased agility in order to easily capture prey.On the other hand,most people don't know that the bull shark`s name originated from its appearance and fighting tendencies.’’Bull sharks get their name from their short,blunt sn...
In warmer waters Bull Shark mating occurs year-round while mating females usually receive mating scars on their dorsum, “the back or outer surface of an organ…” (“dorsum”). They typically carry from one to thirteen pups at one time for ten to eleven months. When the female Bull Sharks gives birth it gives birth to free swimming, live young in their nursery grounds that are again, in areas with low salinity and shallow waters (Curtis). The Pups that survive will be around 56 to 81 centimeters long at birth, and grow approximately to be around 340 centimeters when fully matured (Simpfender & Burgess). Female Bull Sharks are typically larger than males when fully grown and mature; the lifespan for both males and females is around 16 years (Curtis). Females on average are around 180 to 230 centimeters long and 285 pounds, and males on average are around 157 to 226 centimeters and 209 pounds, but the biggest known Bull Shark was reported to be 11.5 feet and 500 pounds (Simpfender and Burgess; Curtis). “Bull sharks are pale to dark grey [on their dorsal, and fade] to white on their [ventral, but on] younger individuals the fins have black
With smiles on our faces we cast our wisely selected lures into the ocean, but we then encountered our first problem of saltwater fishing. Our lures wouldn’t sink. As soon as they hit the water, the ocean current would just buoy them to the surface and, soon after, down current into the line of a nearby fisherman. Improvising our rigs, we dug the heaviest weights out of our tackle boxes and clamped them onto our lures. Sure enough, we got our lures underwater and under control.
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.
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.
The Great white sharks sense of smell is better than a human. A great white shark could smell a drop of blood from at least 500 miles away! Their eyesight is not so good but when a great white shark is being attacked they roll their eyes to the back of their heads so they can protect them. Sharks have an ear stone that senses vibration in the water from over 100 miles away. Sharks are great hunters.
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
Loggerheads are foragers; their strong jaws are beneficial to the ocean seabed. When foraging, loggerheads naturally support and aid to the underwater community (Wilson et al. 2010). While they are foraging, they tend to break up many shells. Loggerheads increase the rate at which those shells disintegrate in the benthic ecosystem. While Loggerheads excavate for their prey, they can change the seabed, which can allow nutrients to move around.
Coral catsharks can grow up to nearly 70 cm in length. They have a small head, catlike eyes, short tail, ten gill slits, a lean body, and two spineless dorsal fins that slant backwards. Coral catshark’s “enlarged branchial (gill) regions enable them to survive very low oxygen levels, high temperatures, and high salinity”. (“Descriptions and”) They are very easy to distinguish due to the white underbody and large quantities of black and white spots that cover the shark from snout to tail. Researchers believe that these sharks reach sexual maturity once they reach 50cm in length. Unlike most sharks, coral catsharks are oviparous. Instead of having a live birth, female’s lay two eggs on the ocean floor, which hatch anywhere from four to six months
The senses of a great white are pretty amazing. This type of shark is able to smell a single drop of blood from a very long distance. A shark’s nose is underneath its snout and when smelling something the signal then goes to the olfactory lamellae. (“The olfactory lamellae are a series of folds on the interior surface of the olfactory sac which increase the surface area giving the shark more opportunity to reg...
The great white shark has 77 rows of 300 teeth. It has a 600 pound bite and it weighs 2,400 thousand pound. It can grow up to be 31 feet and one of the biggest des creatures. It would usually be 100 meters down and likes to eat smaller fish but it might come up and want something bigger and mistake a human for a fish.
...k. Scared and moving back a little more, the shark was in a freeze position no flipping or wobbling, the only thing that was making a move was his gills. Wanting to know more I asked what kind of shark it is and was told that it’s a Caribbean Reef Shark. After the adult left all the children there, we start to poke it with a stick and was touching it with our hands and feet to feel the skin, which felt rough like I was touching sandpaper. When the kids were poking the reef with the stick I thought it would react in a very aggressive way but that wasn’t the case, it was still calm until they start getting aggressive their self. I sacred cause that’s when the reef begun to start snapping at every movement that was making. It was getting too much for me to take especially since it was going out of control, so I left and have no clue as to what happen to the Reef Shark.