The Great White Shark

Carcharodon Carcharias

The great white shark is an exceptionally large shark found in coastal surface waters in all major oceans. Reaching lengths of more than 20 feet and weighing up to 5,000 pounds, the great white shark is the world's largest known predatory fish. 

Great white sharks live in almost all coastal and offshore waters which have a water temperature of between 54 and 75 degrees F. There are greater concentrations off the southern coasts of Australia, South Africa, California, Mexico's Isla Guadalupe, and to a degree in the Central Mediterranean and Adriatic Seas.

In a recent study, great white sharks from California were shown to migrate to an area between Baja California and Hawaii, where they spend at lest 100 days of the year before they migrate back to Baja. On the journey out, they swim slowly and dive down to around 3,000 ft. After they arrive, they change behavior and do short dices to about 980 ft for up to 10 minutes. It is still unknown why they migrate and what they do there (it might be seasonal feeding or possibly a mating area). A similar study showed a great white from South Africa migrating to and from the northwestern coast of Australia in under 9 months (12,000 miles!)

Anatomy & Appearance

The great white has a robust large snout. It has almost the same size upper and lower lobes on the tail fin (built for speed). Great whites are masterfully camouflaged with their white belly and grey dorsal (sometimes brown or navy bluish) shade. The coloration makes it difficult for prey to stop the shark because it breaks up the shark's outline when seen from a lateral perspective. When viewed from above, the darker shade blends in with the sea. When seen from below, the shark's colors only cast a minimal silhouette against the sunlight.

Great white sharks have rows of teeth behind the main ones, allowing any that break off to be rapidly replaced. Their teeth are serrated and when the shark bits, it will shake its head side to side, and like saws, tear off chunks of flesh. They often swallow their own broken-off teeth along with chunks of their prey's flesh.

Diet and hunting

White sharks are carnivorous, and primarily eat fish (rays, tuna, smaller sharks), dolphins, porpoises, whale carcasses, seals, fur seals, sea lions, and sometimes sea turtles. Sea otters and penguins are sometimes attacked, but rarely consumed.

A great white shark primarily uses its extra senses to locate prey from far off. Then, the shark uses smell and hearing to further verify that its target is good. At close range, the shark utilizes sight for the attack. At the moment of contact though, the shark will roll back their eyes and actually be blind. This eye roll is a marvelous way that they protect their eyes from their prey.

Frilled Shark

PREHISTORIC SHARK FOUND ALIVE:

On January 21, 2007, staff at Awashima Marine Park in Shizuoka (southwest of Tokyo) were alerted by fishermen to a "strange eel-like fish with razor sharp teeth". The fish was identified as a pregnant female 1.6 m frilled shark and was captured by park staff who were concerned that the shark appeared to be unhealthy. They took it out of the water and put it into a salt water tank where they filmed it and took pictures of it. The shark died a few hours after capture. This rare surface appearance of a frilled shark has been attributed to the animal being unwell and possibly disoriented.

Superficially, the frilled shark resembles a dark brown or grey eel, but the six gill slits identify it as a shark. The tissue of the gill slits protrudes somewhat, thus inspiring the common name. Its dorsal fin is small, anal fin large, and the caudal fun (tail fin) is highly asymmetric. The dorsal fin is almost unnoticeable. Its teeth are small, but very sharp. This shark has been recorded at up to 6 feet in length. Normally this shark spends its time over 600 meters below the surface. 

This is yet another rare-freaky sea creature that has made its rare-freaky video appearance (courtesy Japanese marine researchers) before promptly declared dead.

Shark Fin Soup Is Horrible.

What IS Shark Fin Soup?
Shark fin soup (or shark's fin soup) is a Cantonese cuisine delicacy commonly served as part of a Chinese feast, usually at special occasions such as weddings and banquets as a symbol of wealth and prestige. The "finning" of sharks required to make this soup has been highly controversial. Some have called the practice brutal, and it is also named as a primary contributing factor in the global decline of many shark species. China's booming economy has resulted in a large increase in demand for shark fins, and this, combined with the importance of this predator in oceanic ecosystems, has exacerbated the problems that the practice is said to perpetuate.


Finning = Death
According to wildlife conservationists, much of the trade in sharks' fins is derived from fins cut from living sharks; this process is called finning. Because shark meat is worth very little, the finless and often still-living sharks are thrown back into the sea to make room on board the ship for more of the valuable fins. When returned to the ocean, the finless sharks, unable to move, either die from suffocation or are consumed by other sharks or animals.



Finning is vigorously opposed by animal welfare groups; both on moral grounds and also because it is listed as one of the causes for the rapid decline of global shark populations.On the IUCN red list there are 39 species of elasmobranches (sharks and rays) listed as threatened species (Critically Endangered, Endangered, or Vulnerable). The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) lists three sharks in Appendix II: the basking shark, the great white shark and the whale shark. Appendix II lists those species that are not in danger of extinction, but which require controls on international trade to maintain their populations. It is estimated that 10–100 million sharks are slaughtered each year for their fins, with a median figure of 38 million. The industry is valued at US$1.2 billion; because of the lucrative profits, there are allegations of links to organized crime. They also raise questions on the medical harm from the consumption of high levels of toxic mercury reportedly found in shark fins.



Numbers of some shark species have dropped as much as 80% over the last 50 years. Some organizations claim that shark fishing or bycatch (the unintentional capture of species by other fisheries) is the reason for the decline in the populations of some species and that the market for fins has very little impact - bycatch accounts for an estimated 50% of all sharks taken- others that the market for shark fin soup is the main reason for the decline.

GOOD NEWS: WAY TO GO AMAZON.COM!!!

Tiger Shark

The animal that will eat almost anything
A tiger shark is inquisitive, and it may approach submerged divers and circle slowly at close range. Do not be lulled into a sense of security by its slow swimming movement and apparent lack of aggression; this shark may nonchalantly take a bite while remaining cool and casual.
The tiger shark, like its jungle namesake, is dangerous; its toll of victims throughout the world is second only to that of the white shark. It is considered the most dangerous tropical shark, and has been blamed for the majority of attacks in Austrailia and Hawaii. The shark's large size, inquisitiveness and often aggressive nature, combined with large cutting teeth and indiscriminate feeding habits, dictates that a tiger shark should always be regarded as extremely dangerous and treated cautiously with a great deal of respect.

What do they look like?

Tiger sharks are about 10 to 14 feet long typically, although they can get as big as 20 feet. They have dark stripes on their back and along their side that resemble markings on a tiger. The stripes fade (with age) to gray or brownish in color. These sharks have a broad, blunt nose, a large wide mouth, and a husky body. They have a whitish underbelly and a long tapered back fin.

Teeth
The tiger shark has very distinct dentintion. The jaws house large teeth with curved cusps and finely serrated edges. Each tooth has a deep notch on the outer margin lined with numerous cusplets. Upper and lower teeth are similar in shape and size and decrease in measurement as they move back toward the mouth's corners.

What do they eat?

These sharks are masterful scavengers. They eat almost anything. They eat sharks (including other tiger sharks), sea turtles, rays, sea birds, dolphins, squid, crabs, clams, birds, mammals, reptiles, and fish. The tiger shark's highly serrated teeth combined with the saw-like action from shaking the head back and forth allows it to tear chunks from much larger marine animals. Interestingly, it is not uncommon to find objects of human origin in the animal's stomach. One large female caught in the Red Sea contained two empty cans, a plastic bottle, two burlap sacks, a squid, and an 8 inch fish. Garbage and refuse is often recovered from the stomachs of sharks caught in harbors and river inlets where it is commonly dumped into the water. Although far from a natural food item, human remains sometime end up in the guts of these scavenging sharks. Tiger sharks are solitary hunters that feed primarily at night as the shark moves further inshore and closer to the surface. Tiger sharks are someimtes seen in groups of several but this is probably a result of congregation of food items in the vicinity.

Where are they?

The tiger shark is found throughout the world's temperate and tropical waters, with the exception of the Mediterranean Sea. It is a wide-ranging species that is at home both in the open oceans as well as shallow coastal waters.


Human Attack Ranking: #2
According to the International Shark Attack Files, the tiger shark has attributed to 29 deaths out of 116 recorded attacks since 1580.

Goblin Shark

On January, 2007, a 4 ft (1.3 m) goblin shark was caught alive in Tokyo Bay, in waters 500 to 650 ft deep. It was taken to the Tokyo Sea Life Park to be displayed in an aquarium, but died two days later on Jan. 27. Later that same year in April, several animals were seen swimming in shallow water in the Japanese Sea. A live one was caught near Tokyo Bay. It is the first time the animals have been seen swimming in such shallow waters.

The goblin shark is a deep-sea shark at depths greater than 200m. This shark feeds on a variety of organisms that live in deep waters (such as deep-sea squid, crabs, and deep-sea fishes). The most distinctive characteristic is the unorthodox shape of its head. It has a long, trowel-shaped, beak-like snout, much longer than other sharks' snouts. Some other distinguishing characteristics of the shark are the color of its body, which is mostly pink, and its long protrusible jaws. When the jaws are retracted, the shark resembles a pink gray nurse shark with an unusually long nose. The pink coloration, unique among sharks, is due to blood vessels underneath a semi-transparent skin (which bruises easily), thereby causing the coloring. The fins are bluish in appearance. Goblin sharks lack a nictiting membrane. They have no precaudal pit and no keels. The front teeth are long and smooth-edged, while the rear teeth are adaptable for crushing.

The goblin shark is a medium-to-large shark. Typically, specimens are 6.6 feet to 9.8 feet in length. Their fins are not pointed and instead are low and rounded, with the anal and pelvic fins significantly larger than the dorsal fins. Their heterocercal tails are similar to the thresher shark's, with the upper lobe significantly longer proportionately than other sharks'. In addition, the goblin shark's tail lacks a ventral lobe.

They can be found throughout the world, from Australia in the Pacific Ocean to the Gulf of Mexico in the Atlantic Ocean. They are best known from the waters around Japan, where the species was first discovered by modern science in 1897. In 2003, more than a hundred goblin sharks were caught off the northwest coast of Taiwan, an area in which they had previously not been found. Reportedly, the sharks were caught a short time after an earthquake occurred in the area.

Very little is known about the species' life history and reproductive habits, as encounters with them have been relatively rare. As seemingly rare as they are however, there seems to be no real threat to their populations and so they are not classified as endangered species by the IUCN.

Whale Shark

The Most Gentle of Giants The whale shark is a slow filter feeding shark that is the largest living fish species. This shark is found in tropical and warm oceans and lives in the open sea. They are slow swimmers.This species is believed to have originated about 60 million years ago.

This species was first identified in April 1828 following the harpooning of a 15.1 ft specimen in Table Bay, South Africa. The name "whale shark" comes from the fish's psysiology; tht is, a shark as large as a whale that share a similar filter feeder eating mode. The largest specimen regarded as accurately recorded, was caught on November 11, 1947 in Pakistan. It was 41.5 feet long and weighed more than 47,300 pounds, with a girth of 23 feet.

As a filter feeder, it has a capacious mouth which can be up to approximately 5 feet wide and can contain between 300 and 350 rows of tiny teeth. It has 5 large pairs of gills. Two small eyes are located towards the front of the shark's wide, flat head. The body is mostly gray with a white belly, and the skin is marked with a "checkerboard" of pale yellow spots and stripes. These spots are unique to each whale shark.

The whale shark is a filter feeder (one of only 3 known filter feeding shark species; basking shark and megamouth shark). It feeds on phytoplankton, macro-algae, plankton, krill, and small nektonic life (such as small squid or vertebrates).

How Filter Feeding Works:

1. The many rows of teeth play no role in feeding; in fact, they are reduced in size in the whale shark. Instead, the shark sucks in a mouthful of water, closes its mouth and expels the water through its gills.
2. During the slight delay between closing the mouth and opening the gill flaps, plankton is trapped against the dermal denticles which line its gill plates and pharynx.
3. This fine sieve-like apparatus, which is a unique modification of the gill rakers, prevents the passage of anything but fluid out through the gills (anything above 2 to 3 mm in diameter is trapped)
4. Any material caught in the filter between the gill bars is swallowed.
5. Interesting fact: Whale sharks have been observed "coughing". It is presumed that this is a method of clearing a build up of food particles in the gill rakers.

This species, despite its enormous size, does not pose any significant danger to humans. It is a frequently cited example when educating the public about the popular misconceptions of all sharks as "man-eaters". They are actually quite gentle and can be playful with divers. There are unconfirmed reports of sharks lying still, upside odwn on the surface to allow divers to scrape parasites and organisms from their bellies. Divers and snorklers can swim with this giant fish without any risk apart from unintentionally being struck by the shark's large tail fin.

Check out the whale shark in motion:
http://www.youtube.com/watch?v=uQrBwN39LJI
http://www.youtube.com/watch?v=KgW7hqhUigM
http://www.youtube.com/watch?v=1vMeTVWdhls&feature=related

Mako Shark

Crew Cuts Off Shark's Head To Save Man

January 27, 2008: A shark's jaws latched so tightly onto a man's leg aboard a fishing boat, that its head had to be cut off to free him. The shark had just been hauled aboard the boar off the Gold Coast. A 20-year-old man from Sydney was bitten by a 9 foot mako shark about 7:30 am on a tuna boat more than 100 nautical miles off Coolangatta.

To read more of this story

MAKO SHARK: "The Fastest Shark in the Ocean"

The shortfin mako can grow to lengths of 13 feet. There is still some uncertainty about its life-span, but it is suspected to reach ages of between 11-23 years. 

As one of the fastest sharks in the ocean, this powerful shark can attain bursts of swimming speeds of up to 40 mph and can leap clear out of the water to heights of up to 20 feet! These qualities have made this species a sought after sport fish in some parts of its range.

The shortfin mako feeds primarily upon bony fish including: mackerels, tunas, bonitos, and swordfish, but may also eat other sharks, porpoises, and sea turtles.

Shortgin mako sharks live in tropical and temperate offshore waters. This shark is seldom found in waters colder than 16 degrees Celsius. The mako, like most sharks, is cold blooded. When the mako starts swimming, its muscles heat up, increasing the overall body temperature, allowing the shark to swim faster.

Distinguishing Characteristics for the Mako:

• Teeth are visible even when the mouth is closed
• Teeth are long and slender with smoothed-edged cusps
• Distinct countershading, dorsally blue and ventrally white
• Moderately short pectoral fins
• Underside of the snout is white
• Lunate tail and caudal keel

INTERESTING CAR:

Chevrolet Corvette Mako Shark 1961

Hammerhead Sharks

AS OF FEBRUARY 19, 2008: ONE OF THE MOST RECOGNIZABLE SHARKS HAS BEEN DECLARED ENDANGERED.

The scalloped hammerhead has fallen victim to indiscriminate fishing and to its valuable fins, which cost up to $800 a kilo in China. This year, the shark will go on the World Conservation Union's Red List of "globally endangered" species, a step below the highest rating of "critically endangered". The 12 foot sharks have almost been obliterated off the US east coast, with a 98% decline since the 1970s.

The Great Hammerhead shark has been known to grow as large as 18 feet, although most Hammerhead sharks only reach about 12 feet long. Hammerhead sharks are found in both open deep ocean and shallow coastal water. During the summer, they may make small migrations towards more northerly areas. The great hammerhead is observed in deep water off the fore reef, in channels, on the reef flat, and in lagoons. Hammerheads are found in tropical waters throughout the world.

 

The Great Hammerhead is a solitary species, rarely seen with other sharks. Scalloped and Smooth Hammerheads on the other hand form small and large schools. Scalloped Hammerhead sharks can often have hundreds of sharks in one school. Other sharks have been known to avoid Great hammerheads and schools of Scalloped hammerheads out of fear of being eaten. Hammerheads often attack and eat other sharks.

It is their flattened wide head that makes the Hammerhead Shark so distinguishable from its relatives. There are a few theories as to why their head is shaped this way. One is for swimming purposes. It is believed that the shape of the head is helpful for turning and also for lift. This would make it easier to swim and also makes it more maneuverable. A second belief on the function of the flatted head involves the Ampullae of Lorenzini (a system of pores densely located around the head and mouth that are their electro receptive system)

Hammerheads are safe for open water diving. Operators often bait the water to attract large schools of Hammerheads. Great Hammerhead sharks are often viewed in deep water a long way from the coast and currents can be strong. Generally, most operators require you to be an experienced scuba diving with at least open water certification. There has only been 12 reported cases of an unprovoked Hammerhead shark attack on a human. Hammerheads will often warn you with threatening postures before attacking.

Recent Hammerhead Articles:

Injured Hammerhead Shark Rescued (Jan 14, 2008)

Female Virgin Hammerhead Gives Birth? (May 2007)

Stop Buying Shark Fin Soup!

Cookie Cutter Shark

The Cookie-cutter Shark is named after the cookie-shaped wounds that it leaves on the bodies of larger animals. It has a cigar-shaped body, a short conical snout and 2 low, spineless dorsal fins. It is dark brown dorsally, lighter below, and has a distinct dark collar, is covered in a dense network of tiny photophores, which in life produce an even greenish glow. 

This species has small, erect teeth in the upper jaw and large triangular teeth in the lower jaw. It has a row of 19 huge teeth (proportionally the largest of any shark species) in the lower jaw. The cookie cutter attaches itself to its prey with its suctorial lips, and then spins to cut out a cookie-shaped plug of flesh from the larger animal.

In addition to plugs of flesh from larger animals, this shark is also know to eat squid. There are even reports of this species leaving crater-marks on the sonar domes of submarines.

Its anteriorly placed eyes may enable binocular vision. This shark grows to 50 cm in length. It feeds by biting pieces of muscle from the bodies of larger marine creatures. This species is recorded from specimens caught in the Gulf of Mexico, off Okinawa, Japan, from the eastern Atlantic and from Australia. They vertically migrate, being found in deep water, probably below 1000 meter during the day, and migrating into surface waters at night.

Horn Shark

The horn shark (also known as the Californian horn shark) gets its name because it has a short, blunt head with high ridges above the eyes. They range in size from approximately 97 cm to 120 cm (around 3 feet long from the tip of the tail to the nose). They are a brownish color covered in black spots and their underbellies have a yellowish tint.

Horn sharks live in rocky reefs and kelp forests although while juvenile, many often stay in open sandy waters. They can be found from central California to the Sea of Cortex and possibly South America in depths that range from 2 to 150 meters.

Adults tend to return to the same resting spot every day. Horn sharks hide in crevices or caves during the day and venture out at night. They nocturnally hunt for urchins, crabs, worms, anemones, and bony fish. 

These sharks are oviparous. That means that they lay egg cases. The horn shark has a distinctive auger shaped egg case with 2 threadlike filaments extending from one end. The egg will typically hatch in 7 to 9 months. They are kelp colored however sometimes they detach from the branch they were wrapped around and many float up and wash onto beach shores.

Horn sharks are not graceful swimmers and sometimes use their strong pectoral fins to crawl along rocks. The teeth lining the front of the horn shark's jaws are sharp and used for grasping prey; while the teeth in the back are flat (molar-like) which is useful for crushing shellfish. The common name 'horn" refers to the spines in front of each dorsal fin (they have 2) that are their main defense against bigger fish (and sharks) that try to swallow them.

Nurse Shark

The Nurse Shark is a beautiful member of the shark family. It has a stout body, obvious barbels, and strong jaws. Behind each eye, it has a spiracle (a special organ that takes in water for breathing when the shark is at rest on the ocean bottom). Nurse sharks are nocturnal hunters and spend most of the day in large, inactive groups of up to 40 individuals. They are often found in the reefs and the ocean bottom during the day in tropical and subtropical waters. By night, the sharks are largely solitary and spend most of the night hunting crustaceans, molluscs, tunicates, and other fish (particularly stingrays).

Nurse sharks can grow up to 13 feet (4.3 meters). Nurse sharks are ovoviviparous (meaning the eggs develop and hatch within the body of the female where the hatchlings develop further until live birth occurs). The gestation period is six months, with a typical littler of 21 to 28 pups. The young nurse sharks are born fully developed at about 30 cm long. They possess a spotted coloration which fades with age.

The nurse shark is not widely commercially fished, but because of its sluggish behavior, it is an easy target for local fisheries. Its skin is exceptionally tough and is prized for its leather. Its flesh is consumed fresh and salted, and its liver is utilized for oil. It has been reported in some unprovoked attacks on humans, but it is not generally perceived as a threat.

Bull Shark

The bull shark is arguably one of the most dangerous species of sharks, but also one of the most facinating. Known by many different common names, this animal has been linked to attacks around the world including some that have occurred deep inland in freshwater rivers and lakes.

They are common worldwide in warm and shallow waters along coasts and in rivers. The bull shark is well known for its unpredicatable and aggressive behavior. Unlike most other marine sharks, bull sharks tolerate not only salt water, but fresh water. They have been spoted hundreds of miles up the Amazon River, Ganges River, and Mississippi River!

The diet of bull sharks include fish, other sharks, rays, dolphins, turtles, birds, molluscs, echinoderms, crustaceans, and even terrestrial mammals. Bull sharks have been known to use the "bump and bite" techniques when attacking their prey. Bull sharks are solitary hunters as they cruise through shallow waters. They can suddenly burst into speed and are extremely territorial.

Bull sharks usually breed in the murky water of river mouths during the summers. Their gestation period is about a year long and one female may give birth to up to 13 live young that are about 28 inches long!

Humans pose the biggest threat to bull sharks followed by larger sharks (great white, tiger, etc) and saltwater crocodiles (may eat them if they enter their freshwater territories). All in all, this is a pretty fascinating animal, especially with its ability to survive in salt and fresh water.