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Information About Sharks And Exactly What They Are - Shark Sider

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Get great information about sharks here, like what exactly sharks are, the different species of shark and how different sharks of the world behave and live.

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Whale vs Shark
Whales are mammals and sharks are fish.

When whales give birth to young ones, sharks lay eggs. Unlike the young sharks, young whales are fed milk. The whales raise their young ones whereas sharks do not.

Whales have bones whereas the sharks have no bones but only cartilage. Whales are much larger than sharks. The blue whale is the largest of all the mammals on Earth. When a whale weighs more than 100 tons, the shark weighs about 2,000 kg.

Sharks hunt for their food. Whales do not have this hunting tendency. Plankton and krill are the food of whales. However, toothed whales feed on squid and small fish. Sharks feed on fish and all marine animals. Sharks may eat other sharks whereas whales do not eat other whales.

Whales produce sound by which they communicate with each other and search for food. Whales produce many types of noise and even sing. Sharks do not have these types of communication skills.

Whales can reach a height of 35 meters, and the shark can reach a height of six meters.

Sharks are not known to sleep, but there is a possibility that whales do sleep as they are mammals.

Whales are very friendly towards human beings and especially dolphins which are known to swim along with swimmers. Whales are also trained for entertainment in wildlife parks and Sea World parks. Sharks are not friendly and not trained for entertainment.

Sharks react involuntarily because of instincts. Whales are known to have self-determination as old and injured whales are known to commit suicide.

Whales migrate seasonally from one place to another. Sharks have no such migrating tendency. Whales are also endangered whereas sharks are not.

Summary:

1.When a whale weighs more than 100 tons, the shark weighs about 2,000 kg.
2.Whales give birth to young ones; sharks lay eggs.
3.Plankton and krill are the food of whales. However, toothed whales feed on squid and small fish. Sharks feed on fish and all marine animals.
4.Whales produce sound by which they communicate with each other and search for food. Sharks do not have communication skills.
5.Whales are endangered whereas sharks are not.
6.Whales are very friendly towards human beings and especially dolphins which are known to swim along with swimmers.
7.Sharks react involuntarily because of instincts. Whales are known to have self-determination as old and injured whales are known to commit suicide.

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Difference Between Whale and Shark Whale vs Shark Whales are mammals and sharks are fish. When whales give birth to young ones, sharks lay eggs. Unlike the young sharks, young whales are fed milk. The whales raise their young ones whereas sharks do not. Whales have bones whereas the sharks have no bones but only cartilage.

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Living in the same ecosystem, sharks and dolphins are two different types of animals. Shark is a cartilaginous fish, whereas the dolphin is a mammal live, in the marine ecosystem. Both these species have got the peoples' attraction for their magnificence, intelligence, playfulness, fearsomeness...etc. Sometimes, there may be instances to identify dolphins as fish as they live in water. Therefore, it is important to discuss the differences and similarities between sharks and dolphins in a Zoological perspective.
Shark
By the name of shark, it sounds dangerous, and that is because of their carnivorous food habits. This cartilaginous fish (Class: Chondricthyes) is a diverse group of animal with about 440 species. Sharks can live in deep as well as shallow waters, and their sizes also vary drastically between 15 centimetres (a deep sea shark) and 12 metres (whale shark). They are extremely well adapted for a predatory lifestyle with sharp teeth, strong jaws, highly streamlined body, keen eyesight, excellent olfactory sense, sharp hearing ability, and electroreception to sense other animals. They indeed have the most developed electro sense among animals. Sharks are the top predators in the marine ecosystem. They can prey on any animal within their grasp. Presence of dermal denticles (made of collagenous fibres) and their arrangement surrounding the body provide shark an outer skeleton. Swimming muscles are attached to those denticles and that saves energy while producing very rapid movements in the shark. There is another important feature in sharks, which is the shape of the tail or the caudal fin. The shape of tail varies within species (e.g. Tiger shark, Great white shark, Coockiecutter shark). Sharks do not have swim bladders, but the liver is large and filled with oil and their cartilaginous skeleton is light, providing them a great buoyancy. Respiration occurs through the gills and most sharks live about 20 - 30 years.
Dolphin
These popular mammals live in the sea like their relatives, whales. There are about 40 species of dolphins that are distributed throughout the world. Mostly, the dolphins are found in shallow waters. The size of a dolphin can vary within one to ten metres of length, and from 40 kilograms to 10 tonnes of weight. Dolphins are the largest group of the Order: Cetacea. They mostly prefer fish and squids for their food. Dolphins are intelligent, and they herd together most of the time to restrict the fish schools into small volumes and feed on them. Sometimes they chase the fish into shallow waters so that the catching would be easier, which method is called the corralling. Their streamlined body makes them fast swimmers. However, dolphins breathe fresh air from their lungs. Sleeping behaviours have also been observed, and their remarkable whistling and whining sounds have been recorded. The usual lifespan of a dolphin is about 20 years.

What is the difference between Shark and Dolphin?

- Dolphins possess the mammalian features, whereas sharks are a group of fish.

- Sharks are more diversified than dolphins.

- Sharks are notorious hunters, whereas dolphins are not so.

- Dolphins breathe fresh air by their lungs, while sharks extract Oxygen from water through gills.

- Dolphins prefer shallow waters, but sharks do not seem to prefer a particular habitat in the sea, and instead they are found everywhere.

Despite all these differences, both these animals have been a top attraction of people.

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Difference Between Shark and Dolphin - DifferenceBetween.com

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Shark vs Dolphin Living in the same ecosystem, sharks and dolphins are two different types of animals. Shark is a cartilaginous fish, whereas the dolphin is a mammal live, in the marine ecosystem. Both these species have got the peoples' attraction for their magnificence, intelligence, playfulness, fearsomeness...etc.

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The information on the behavior of these Chondrichthyes is scarce when compared to other fish or mammals, and is because sharks hardly meet the necessary conditions for human research. Rarely they stay in the same place, and most of the time they inhabit inaccessible areas for research.

Most sharks make most of their activities during the afternoons and prefer to hunt at night. They are usually solitary: they swim and hunt alone most of the time, but they meet with other sharks in some special cases, like the period of mating or the zones abundant in food.

Some species show a social structure based on groups called "schools" without a strong reason for this because sharks do not need special protection against predators. The sharks that socialize usually segregate according to the size of the individuals.

Some species show a social structure based on groups called "schools".

Hammerhead sharks are an obvious example of social sharks with a clear hierarchy, and it is common to find them gathered around islands and other areas with an abundant food source. Other species try to be careful with them, as their excellent maneuverability given by the shape of their heads is advantageous compared to other sharks.

However, some species hunt in groups when it comes to obtaining a large prey. Sharks form large groups, and all cooperate first by surrounding the prey, and then, when they are already captive, they gradually approach it until one of the predators takes the first bite. It is then that the others begin to attack and end with the prey. This cooperative behavior is extremely rare.

The methods of hunting in this predators are different and make the element of surprise their primary weapon. Benthic sharks, for example, camouflage themselves beneath the bottom of the ocean and if they detect a possible prey, they stay still, waiting for the animal to get close enough to attack it from below and occasionally, to swallow it whole.

In contrast, pelagic predators must cautiously approach the prey and hurl themselves at it before it knows what is happening. Sometimes, before eating, they perform an entire display of exaggerated movements that they intend to threaten. If it is a large animal, sharks wait for it to bleed to death and then eat it.

Hunting activities require a lot of energy, and as a consequence, large predatory sharks feed only a few times a week and are not always eating, as is often believed. Small species, on the other hand, eat a couple of occasions during the day since their prey are also small.

Their feeding behavior changes according to the presence of prey and the competition for them. If sharks stimulation is intense, it is possible that the excitement increases and they are victims of a frenzy that results in cannibalism.

Migration is a fundamental activity for some sharks, whose motive is the search for food as their prey also migrate and to reach the areas where they mate and spawn. Their journeys can take them through all the ocean basins traveling thousands of kilometers during a year. Sharks remember the migration patterns of their favorite prey and do not hesitate to follow them, but their migratory patterns become more complex than those of birds.

Sharks remember the migration patterns of their favorite prey.

Occasionally they congregate around fishing boats because they remember that the fishermen throw discarded animals.

Several species can travel at the same time, and until recently, some thought that most stayed in one place, but that is not accurate. For example, blue sharks (Prionace glauca) can migrate from the United States to Brazil, which is a significant distance. Another famous migrant is the whale shark (Rhincodon typus), which goes to specific areas to spawn in corals.

It is worth remembering that not all sharks are aggressive and they do not attack for pleasure. Many species are characterized by their docility and even by their timidity. As an example, the shark whale mentioned above is very peaceful, quiet and does not react with fear or aggression to the proximity of humans.
Sources:
https://en.wikipedia.org/wiki/Shark#Behavior

http://www.defenders.org/sharks/basic-facts

https://seaworld.org/en/animal-info/animal-infobooks/sharks-and-rays/behavior

http://animaldiversity.org/search/?q=shark&feature=INFORMATION

http://www.arkive.org/
BioExpedition Publishing © 2017.

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The information on the behavior of these Chondrichthyes is scarce when compared to other fish or mammals, and is because sharks hardly meet the necessary conditions for human research. Rarely they stay in the same place, and most of the time they inhabit inaccessible areas for research.

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Shark Behaviour

A sharks behaviour is completely linked to their amazing array of senses. These senses influence every part of their lives. Low frequency sounds can travel great distances under the water and the sharks complex hearing system allows them to be the first to detect an interesting target.

Depending on species, sharks can be either solitary, gliding through the water in search of food, or gregarious in the form of schools containing over 100 individuals. The Scalloped Hammerheads are a prime example of one species of shark that congregate in large numbers. However, even solitary sharks occasionally meet for mating or on hunting grounds which may lead them to cover thousands of miles a year.

Are sharks intelligent?

Despite the common myth that sharks are instinct-driven eating machines, recent studies have indicated that many species possess powerful problem-solving skills, social complexity and curiosity. The brain-mass-to-body-mass ratios of sharks are similar to those of mammals and other higher vertebrate species.

Sharks have a tendency to work together as a team. A few years ago, a group of seven sharks were observed near Smitswinkel Bay in South Africa working to relocate a partially beached dead whale into deeper waters so that they all could feed upon it.

Groups of sharks, roughly the same age and gender, tend to return to the same area each year. Sharks have been observed returning to a particular place and patrol the same bays every year at the same time. Each year, they bask and communicate with each other with body movements and are present at each others kills. A particular species renown for this behaviour is the Grey Reef Shark.

Sharks have even been known to engage in playful activities Porbeagle sharks have been observed repeatedly rolling over and over again in kelp and then being chased by another with a piece of kelp trailing behind them.

Do Sharks Sleep?

Sharks need to keep moving in order to breathe, however some shark species have been observed resting on the sea bed actively pumping water over their gills. Sharks tend to have active and inactive periods rather than sleep.

A Nurse shark is able to rest motionless while other sharks have to keep moving to survive. Sharks eyes do not close while they are inactive. They have been observed inactive as though they were asleep, but their eyes have been actively following divers swimming nearby. It is also known that sharks can continue swimming while apparently being 'asleep' such as in the case of the Dogfish.

The spinal cord of the Dogfish coordinates its swimming instead of its brain allowing it to swim whilst 'asleep'.

Shark Attacks

Contrary to popular belief, only a few sharks are dangerous to humans. Out of more than 360 species, only 5 have been involved in a significant amount of fatal unprovoked attacks on humans: the Great White Shark, Tiger Shark, Oceanic Whitetip Shark, Hammerheads and Bull Sharks. These sharks, being large, powerful predators may sometimes attack and kill people, but all of the above sharks, even the Great White, have been filmed in open water, with no cage, time and time again, without any attacking incidents occurring.

The Oceanic Whitetip Shark is not often involved in unprovoked attacks. This is mainly because it lives in the open sea and not near coasts. However, in the past, it has been involved in the aftermath of several air and sea incidents.

When some sharks (like the Great White or the Grey Reef shark) turn aggressive prior to an attack, they arch their back and throw back their head.

This places their mouth in a better position for taking a big bite. They also move their tail more acutely (probably in preparation for a chase).

On average, there are only about 100 shark attacks each year and only 10 of those result in a human death.

However, people kill thousands of sharks every year for sport and for food. Shark skins are used to make products like any other leather would be. Up until the 1950's, shark livers were used as a vitamin A supplement.

There are many reasons why sharks do sometimes attack humans. One of the more obvious reasons may be that from beneath the ocean surface, a human could be mistaken for shark prey such as a seal. This would be a typical theory in regards to attacks on surfers. When lying on their boards their shape does resemble a seal from beneath the surface.

Sharks have sensory organs on their noses that detect movement. A shark will also only bite a human once and then retreat from its target. This may be because humans do not taste nice or because we do not have the necessary fat such as a seals blubber. Why sharks retreat after the first bite is not clear. One theory could be that the shark waits for the injured target to exhaust himself or die before returning to feed on the remains or, as above, we are not popular on the 'sharks menu'.

Another theory is that the electrical receptors, which pick up movement, do not pick up the same signals from a wounded human as they would a wounded seal, and so they are more cautious. In fact, it has recently been shown that surfers do not give off the same electrical signals as seals, or it is thought there would be far more attacks.

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Shark Behaviour Facts - Research & Characteristics

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A sharks behaviour is completely linked to their amazing array of senses. These senses influence every part of their lives. Low frequency sounds can travel great distances under the water and the sharks complex hearing system allows them to be the first to detect an interesting target.

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Interestingly, although sharks have been considered to be relatively unintelligent animals, they have been observed displaying cooperative and insightful behaviour. They have been seen to be curious and able to work in packs to solve a problem (e.g. moving a large dead whale into deeper waters).

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Explore the wild world of animals. Discover opportunities to care and conserve. Connect through our camps, courses, and careers at SeaWorld and Busch Gardens.

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In order to better understand and know the many fascinating shark species, it is vital to take such factors as their diet into account. As human beings continue to fish and pollute the waters, the prey populations continue to deplete.

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Teaching Tools | Resources for Teachers from Scholastic

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Some types of Sharks

There are many species of sharks found in the oceans around the world.

Some of them are very big while others are quite small. Some of them are to be feared while others mind their own business and they are very calm. You may be surprised to learn some of the largest species of sharks in the ocean are the nicest ones to encounter.

This information will help you identify some of the common species of sharks.

There are 440 different species of sharks in the world today classified into eight different orders described below with some examples of known sharks species for each group.

Some of the most popular species of sharks are:

Characteristics of some Types of Sharks

Angel Sharks

One of the most unusual types of sharks our there are know as angel sharks. Many people mistake them for some other types of sea creature. It isn't uncommon for them to be thought of as large stingrays. But the simplest way to tell them apart is by looking at the location of the fins. On the angel shark, they won't be on the head.

This type of shark isn't a meat eater. Instead it focuses on what it can find along the bottom of the ocean. Clams and mollusks often are a big part of their overall diet.

The coloring of angel sharks allow them to blend in well with the bottom of the ocean though so they often go undetected.

Hammerhead Sharks

Another unique type of shark is the Hammerhead Shark. It has a long head that looks like they ends of a hammer on both sides of it.

Many people are afraid of it due to the way that it looks. Yet it is very unlikely that they will attack a person. Nine hammerhead species are generally recognized but only three types can be dangerous to humans.

Hammerhead Sharks have a very developed sense of smell though and they will go on the hunt for prey in the ocean very aggressively. Read the complete Fact Sheet about the Hammerhead Shark...

Reef Sharks

Reef sharks seem to be able to adapt to life just about anywhere including captivity. They are loners and very seldom interact with other sharks unless it is time for breeding.

Reef Sharks can grow up to six feet long and they have very distinct features. They are gray in color on the top. Underneath they are all white or they have streaks of white. The tips of their fins are black.

Blue Sharks

All sharks swim very fast, but the blue shark is one of the fastest species.

Blue Sharks often look hungry due to the thin body they have. However, they are slender by nature and it has nothing to do with the amount of food they eat. Due to the roundness of most other types of sharks though they do seem quite on the thin side. They aren't picky at all about what they will eat though so they never go hungry.

The blue shark is considered to be one of the most dangerous sharks in the waters. It has been known to attack people, which makes it one of species of shark that people most fear.

Blue sharks can grow up to 12 feet long so this is no small shark to be trying to get away from. Due to the speed and the strength of it very few of its prey have a chance of survival. Read the Blue Shark Fact Sheet

Great White Shark

Probably the best known species of shark is the great white. This is believed to be the most dangerous type of shark in the world. People have been able to see them as they are among the rare species that do raise their heads out of the water.

Great white sharks can grow up to 16 feet and weight around 1,500-2,400 pounds. Some have been known to weigh around 4,000 pounds but that isn't the norm.

More people have been attacked by great white sharks than any other shark species. Locations where they are living have been identified and people are encouraged to stay away from them. Even so, swimmers, surfers, and divers have had numerous encounters with them. Read the Great White Shark Fact Sheet.

Grouping Sharks

While all sharks have similarities including they way their bodies are formed they also have many differences. Now that you are aware of some of the different types of sharks out there you can look into those that capture your attention in more detail. Sharks are very interesting and you will find there is an abundance of information out there to explore.
Physical Characteristics of Each Group

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There are many species of sharks found in the oceans around the world. Some of them are very big while others are quite small. Some of them are to be feared while others mind their own business and they are very calm.

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Types Of Sharks: Shark Species List With Images & Info - Shark Sider

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There are over 400 different types of sharks in the World. Come learn about them all in this super list of different shark breeds. This is cool stuff!

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Certain shark species will remain in a fairly confined habitat for their entire lives. Others, such as the Blacktip and Tiger sharks, may migrate for short distances (up to 1000 miles). Highly pelagic species are capable of travelling across entire oceans. Examples of these include the Blue Shark and the Mako.

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habitat

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Sharks don't roam all areas of the ocean as some people fear. While it is true that occasionally they are spotted in locations that they normally wouldn't be it has to do with their needs. For example if something is wrong in their normal habitat such as severe pollution, an oil spill, or even a lack of food then they will search out other locations where they can reside.

They aren't territorial like so many types of animals are. So they are free to roam the waters. The females don't stay to care for their young so for those species who lay eggs, they have not trouble placing them in a hidden location and then being on their way. They young sharks care for themselves from the very moment they hatch.

Sharks easily Adapt

Sharks are very good at adapting to new situations and environments which is why they have survived in the water for millions of years.

The habitat of a shark depends on the species though. Sharks are cold blooded, and that would usually imply that they would search for areas where the temperatures are very cold. However that is not true as there are sharks living in warm, temperate and cold waters.

It is understood that sharks are going to live where the water is deep enough that they can be well hidden. This allows them the ability to swim freely around in the body of water. Of course they need to reside where they can find enough food to survive on. Since sharks have very few enemies they are able to move freely around in the water as they desire. They are loners for the most part so they don't travel together.

However, many sharks live closer to the surface in order to find the sources of food they are after. They often don't eat daily though so they can dwell deeper in the water in between feedings. They will follow the trail of food when they need to so they can travel hundreds of miles to find what they need in order to survive. Generally the more food they can live on in a general area though they more they will remain in one spot.

Most species of sharks reside in saltwater which means they are found in the oceans. However, some of them are known to live in bodies of fresh water.

There are many who worry that humans are destroying the natural habitats of sharks. We continue to pollute the waters and to remove various sources of food from the water for our own use. As a result sharks have to move to locations that were once free of them if they wish to continue surviving.

Some sharks now reside in fake habitats along with other types of aquatic live. This is to preserve them. Most are in exhibits at very expensive locations found around the world.

Millions of people pay to go see them up close though as they walk through tunnels with the sharks on both sides swimming around. Others are carefully observed by researchers in order to learn more about certain species of sharks. Not all species do well in captivity though so the process is very selective.

Even with specific locations where sharks are known to live, it is important to always keep an eye out for them when you are in open bodies of water. Sometimes they travel to other destinations. While you don't want to be afraid of the water due to the risk of a shark being present, you do want to take some precautions.
Sources:
https://seaworld.org/en/animal-info/animal-infobooks/sharks-and-rays/habitat-and-distribution

http://www.bbc.com/earth/story/20150611-sharks-epic-migration-revealed

https://en.wikipedia.org/wiki/Shark#Range_and_habitat

http://www.iucnredlist.org/
BioExpedition Publishing © 2017.

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Sharks don't roam all areas of the ocean as some people fear. While it is true that occasionally they are spotted in locations that they normally wouldn't be it has to do with their needs.

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Survival of the fittest

The process of evolution through natural selection or global events (i.e. ice ages, volcanic eruptions, asteroid strikes, and human driven extinctions) has claimed the fates of many species and species groups over the millennia. Sharks, however, stand out as one of the few families to survive both cataclysmic events and the slower genetic process of natural selection. Sharks are one of evolutions most classic and enduring success stories. The earliest ancestors of modern sharks can be traced back about 425 million years, which is 200 million years before the earliest known dinosaurs! However, don't confuse ancient with being primitive. Sharks have gone through the process of adaptation and evolutionary experimentation as well. The modern descendants of ancient sharks have incorporated many of the successful traits of the past. They have changed over time, but the changes have not been too extreme, only nature perfecting an originally near-perfect design.

Below is a list of a few of the characteristics that the great white shark was been equipped with by nature. Some of the traits are unique to sharks, others unique to specifically the great white shark.

- Their skin colour represents a type of camouflage called counter-shading. Great whites are dark grey on top and white on the bottom, which not only breaks up their outline in the water making them difficult to see, but they blend in with the darker sea-floor when viewed from above and the lighter surface when viewed from below.

- The upper jaw of sharks, including the great white, is not fused to the skull as it is with other vertebrates, but is held in place by flexible connective tissue. This allows the jaw to protrude outward from the head, extending its reach and bite radius!

- The great white is a highly visual hunter and it is believed they have acute colour vision

- Great whites have electroreceptors, which are sensory organs that allow them to detect hidden prey by means of sensing the minute electrical signals they give off.

- Great whites are unique among sharks in the sense that they are endothermic, which means they can regulate their blood temperature. Networks of arteries and veins on either side of the shark keep the blood warm allowing them to retain metabolic heat. This process allows them to conserve energy for hunting, allowing the sudden bursts of speed that propels them into the air when hunting seals (such spectacular breaching events can be witness with African Shark Eco-Charters on our trips in False Bay!!)

These adaptations, along with many others give these seemingly prehistoric predators an edge, especially when it comes to hunting cape fur seals. Sharks, and specifically great whites, are fascinating representations of a perfect predator and have been for millions of years.

Come witness these spectacular animals in action in their natural environment with Africa n Shark Eco Charters in False Bay!

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Great White Sharks-Survival of the fittest

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Survival of the fittest The process of evolution through natural selection or global events (i.e. ice ages, volcanic eruptions, asteroid strikes, and human driven extinctions) has claimed the fates of many species and species groups over the millennia. Sharks, however, stand out as one of the few families to survive both cataclysmic events and the slower genetic process of natural selection.

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Sharks play a vital role in the oceans in a way that the average fish does not. Most sharks serve as top predators at the pinnacle of the marine food pyramid, and so play a critical role in ocean ecosystems. Directly or indirectly they regulate the natural balance of these ecosystems, at all levels, and so are an integral part of them. As they usually hunt old, weak or sick prey, they help to keep the prey population in good condition, healthy and strong, enabling these more naturally fit animals to reproduce and pass on their genes. The effects of removing sharks from ocean ecosystems, although complex and rather unpredictable, are very likely to be ecologically and economically damaging.

Top reasons why you shouldn't kill/consume sharks

Due to overexploitation and lack of proper management, many shark species are under considerable risk of unrecoverable decline with some species having declined to near extinction in recent years.According to reports, sharks are being killed at an alarming rate of up to 273 million worldwide per year . Some experts predict that if the killing continues at the current rate many species will be lost forever with potentially devastating implications for our ocean ecosystems.

In a study off the east coast of the United States, 11 species of sharks were virtually eliminated from their range. Of the 14 species of marine life that those sharks used to eat, the populations of 12 exploded and caused great damage to the ecosystem. For example, the cow nose ray population was no longer kept under control by sharks and so grew out of control. As a result, the rays destroyed the population of bay scallops, their favoured food. The scallop fishery, which had been thriving, sustainably, for over 100 years, was virtually wiped out, with scallop catch dropping to only 13% of its high point. In addition, the removal of the scallops likely had an effect on water quality as they were no longer there to perform their function of filtering and cleaning the water.

Heavy metals and other environmental toxins accumulate in plant and animal tissues through the well-documented process of bioaccumulation. Sharks are prone to bioaccumulation through diet ( biomagnification) as they incorporate metals very efficiently and eliminate them slowly. Eating shark meat exposes you to these potentially dangerous toxins, in particular, high levels of the methyl mercury. While a certain amount of mercury in the environment is natural, growing worldwide pollution of our oceans is increasing the risk of high mercury levels in the fish we eat, particularly fish at the top of the food chain like sharks. Consuming sharks will increase the level of mercury you ingest which will in turn increase your risk of neurological disorders, autism, infertility, Coronary heart disease or even death.

Sharks regulate the behaviour of prey species, and prevent them from over-grazing vital habitats. Some shark researchers believe that the intimidation factor caused by sharks may actually have more of an impact on the ecosystem than what sharks actually eat. For example, scientists in Hawaii found that tiger sharks had a positive impact on the health of sea grass beds. Turtles, which are the tiger sharks' prey, graze on sea grass. In the absence of tiger sharks, the turtles spent all of their time grazing on the best quality, most nutritious sea grass, and these habitats were soon destroyed. When tiger sharks are in the area, however, turtles graze over a broader area and do not over-graze one region.

While a huge demand for shark fins in Asia results in the slaughter of tens of millions of sharks annually, a study found that sharks are worth far more alive than dead. In Palau, where more than half of tourists are drawn by diving excursions, each reef shark brings in about $179,000 in tourism revenue annually, or about $1.9 million during its lifetime. By comparison, a single shark's fin, sold for shark fin soup, fetches only about $108.

The loss of sharks from certain areas may be an indicator of an ecosystem out of balance and in trouble. Provided that sharks have not been fished out of certain areas it is reasonable to assume that their disappearance would be a result of the destruction of a suitable habitat. The fact that shark species are so diverse and inhabit every ocean on the planet makes them key players essential to the ocean environment. Yet despite their importance in the marine food-chain they remain a low conservation priority. For all their evolutionary success and apparent menace, sharks are incredibly fragile, unable to withstand the increased pressures forced on them by the voracious world fishing industries. This is partly due to the fact that sharks are slow growing animals that mature late, live long, and have a low reproduction rate.

Sharks have evolved in a tight inter-dependency with their ecosystem. They tend to eat very efficiently, going after the old, sick, or slower fish in a population, keeping that population healthy. Sharks groom many populations of marine life to the right size so that those prey species don't cause harm to the ecosystem by becoming too populous. The ocean ecosystem is made up of very intricate food webs. For the most part, sharks are at the top of these webs and are considered by scientists to be " keystone" species, meaning that removing them may cause the whole structure to collapse. For this reason, the prospect of a food chain minus its apex predators may mean the end of the line for many more species. Scientific studies demonstrate that depletion of sharks results in the loss of commercially important fish and shellfish species down the food chain, including key fisheries such as tuna and other important fish species that maintain the health of coral reefs.

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Sharks play a vital role in the oceans in a way that the average fish does not. Most sharks serve as top predators at the pinnacle of the marine food pyramid, and so play a critical role in ocean ecosystems.

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Water pollution effects on marine life are a trending issue in terms of environmental concerns. Water pollution affects humans. It affects terrestrial organisms. It affects marine organisms. Today's post focuses on the impact of water pollution on marine organisms including sharks. Although Twitter is rife with comments slamming the scientific integrity of Discovery Channel's Shark Week, I have enjoyed their footage of these ancient creatures 😳 and just try to keep perspective. They are bringing some positive publicity to these creatures at least 😉

How Water Pollution Affects Marine Life

Marine organisms are affected by pollution in many ways but the most profound, long-term damage comes from the bioaccumulation of toxins such as metals, pesticides, herbicides and pharmaceuticals that make their way to the ocean.

Bioaccumulation - a general term for the accumulation of substances, such as pesticides (dd t is an example), methylmercury, or other organic chemicals in an organism or part of an organism.-biology online

Most of these toxins can't be removed from the body and are stored in organs and muscle tissue. These toxins begin in low levels in microorganisms such as plankton which filter-out these toxins. Small fish eat hundreds of these plankton also ingesting the toxin and accumulating much more. Big fish consume a large number of small fish accumulating an even larger concentration of the toxins until you reach apex predators - you get the picture!

Most marine mammals and sharks are at the top of their food chains and toxins accumulate in their fatty tissues and the breast milk of mammals. Bioaccumulation of toxins affects marine life in many ways:

their endocrine systems (affects hormone production) may suffer damage

young many experience deformations

juveniles may experience growth and developmental issues including skeletal problems, weakened immunity and neurological problems

cases of cancer in marine organisms increases

Particularly sharks and marine mammals at the top of their food chains experience heavy metal accumulation:

cadmium constricts blood vessels, increases heart rate and kills sperm

mercury interferes with salt secretion and kills sperm

zinc impairs gill function

copper increases blood pressure

Sheltered bays which are often used as breeding and mating grounds by large marine organisms have lower water exchange resulting in the accumulation of toxins to dangerous levels. DDT, mercury and organochlorines have been found in higher levels in sharks and marine mammals found in closer proximity to human populations.

Water pollution also affects marine life in more immediate ways:

lost or abandoned fishing gear can penetrate or wrap around gills or body parts causing more immediate death or a slow, painful death due to infection or slow strangulation

plastic wrapping straps get caught around the gills of young sharks cutting into flesh also causing slow, painful death.

Top 10 Toxic Organisms

Bob Bohle of BlueVoice.org has compiled a list of the organisms containing the highest amounts of toxins accumulated from their environments.

1. Bottlenose Dolphin

2. Orca

3. Risso's Dolphin

4. Harbor Seal

5. Beluga Whale

6. Mediterranean Monk Seal

We are tied to the ocean. And when we go back to the sea, whether it is to sail or to watch - we are going back from whence we came. - John F. Kennedy

7. Gray Seal

8. Polar Bear

9. Stellar's Sea Eagle

Sources

Bohle, Bob. The Effects of Ocean Pollution on Marine Mammals. 2007. BlueVoice.org

Martin, R. Aiden. A Place for Sharks. 2003. Biology of Sharks and Rays at ReefQuest Centre for Shark Research. August 13, 2014.

Shark Savers. Other Threats Facing Sharks. 2014. WildAid. August 13, 2014.

[otw_shortcode_info_box border_type="border-top-bottom" border_style="bordered" icon_type="general foundicon-heart" border_color="#ff954a" icon_color="#ffcd78″]What are your feelings about the plight of large marine organisms? Perhaps we may think twice about the things we flush down the toilet or throw into water bodies. Most water systems ultimately connect to the ocean. Humans have an intimate connection with marine ecosystems. As much of humanity survives on marine food, or enjoys their lobster or fish at their local sea food place, bioaccumulation of toxins in the marine ecosystem has some direct impact on most of us. Feel free to add your thoughts on this issue in the comments below![/otw_shortcode_info_box]

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How Does Water Pollution Effect Marine Life?

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Water pollution effects on marine life are a trending issue in terms of environmental concerns. Water pollution affects humans. It affects terrestrial organisms. It affects marine organisms. Today's post focuses on the impact of water pollution on marine organisms including sharks.

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Not only was Megalodon the biggest prehistoric shark that ever lived; it was the largest marine predator in the history of the planet, vastly outweighing both the modern Great White Shark and ancient reptiles like Liopleurodon and Kronosaurus. Below you'll find 10 fascinating facts about Megalodon.

Megalodon Grew Up to 60 Feet Long

Since Megalodon is known by thousands of fossilized teeth but only a few scattered bones, its exact size has been a matter of contentious debate. Over the past century, paleontologists have come up with estimates, based mainly on tooth size and analogy with modern Great White Sharks, ranging from 40 to 100 feet from head to tail, but the consensus today is that adults were 55 to 60 feet long and weighed as much as 50 to 75 tons--and some superannuated individuals may have been even bigger.

Megalodon Liked to Bite the Fins Off Its Prey

According to at least one computer simulation, Megalodon's hunting style differed from that of modern Great White Sharks. Whereas Great Whites dive straight toward their prey's soft tissues (say, a carelessly exposed underbelly or the legs of a wading swimmer), Megalodon's teeth were especially suited to biting through tough cartilage, and there's some evidence that this giant shark may have first sheared off its victim's fins (rendering it unable to swim away) before lunging in for the final kill.

Megalodon's Closest Living Relative Is the Great White Shark

Technically, Megalodon is known as Carcharodon megalodon--meaning it's a species (Megalodon) of a larger shark genus (Carcharodon). Also technically, the modern Great White Shark is known as Carcharodon carcharias, meaning it belongs to the same genus as Megalodon. However, not all paleontologists agree with this classification, claiming that Megalodon and the Great White arrived at their striking similarities via the process of convergent evolution.

Megalodon's Teeth Were Once Known As "Tongue Stones"

Because sharks are constantly shedding their teeth-thousands and thousands of discarded choppers over the course of a lifetime-and because Megalodon had a global distribution (see next slide), Megalodon teeth have been discovered all over the world, from antiquity to modern times. It was only in the 17th century that a European court physician named Nicholas Steno identified peasants' prized "tongue stones" as shark teeth; for this reason, some historians describe Steno as the world's first paleontologist.

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We're Going to Need a Bigger Boat: 10 Facts About Megalodon

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Not only was Megalodon the biggest prehistoric shark that ever lived; it was the largest marine predator in the history of the planet, vastly outweighing both the modern Great White Shark and ancient reptiles like Liopleurodon and Kronosaurus. Below you'll find 10 fascinating facts about Megalodon.

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Tags: Threats, Environment

Recreational Fishing

There has been a lot of attention placed on the impact of commercial fishing on shark populations, which is well warranted considering the sheer scale of the catches. However, the overall impact of recreational fishing on shark populations is not well studied and is typically difficult to detect.

Recreational fishing for sharks is popular in many places like the United States, Australia, New Zealand, and the United Kingdom (Babcock 2008). Several species are targeted by recreational fishermen, such as blue sharks, shortfin mako, porbeagle, and thresher sharks (Camhi et al. 2009).

Some recreational shark fishermen do practice catch and kill techniques just for fishing records or to obtain jaws or mounts as trophies. Despite the fact that most sport fishermen are responsible stewards of the sea, some fishermen do heavily target sharks and may have a significant impact on some species, such as bull sharks (Casey and Hoey 1985) and blue sharks (Campana et al. 2006). Reports from this type of tournament indicate that fishermen have caught and killed large pregnant females and sharks of threatened species.

Fishermen and tournaments are changing to catch and release techniques. The most important aspect of this fishing is how the shark is caught, handled and released. If proper techiques and guidelines are not followed, the shark may become stressed and if released, it may not survive. Some sharks are more susceptible to death after release than others. Therefore, fishermen engaging in catch and release shark fishing need to be familiar with the species they may encounter and know how to quickly and efficiently get the shark off the hook and back in the water. Catch and release fishing should also be done carefully near areas of vulnerable shark populations, such as nursery and pupping grounds (Gallagher et al. 2012).

Liver Oil

Humans have utilized sharks throughout history. The fishery for and trade in shark liver oil, called Squalene, started because the compound was used as machine lubricant but was subsequently replaced by synthetics. Now, Squalene is marketed as an expensive ingredient in cosmetics and lotions (Vannuccini 1999) and is being sold in the form of a pill as a health supplement, the benefits of which are still inconclusive.

The fisheries targets deepwater sharks because their large livers, constituting up to 30% of their body weight. These deepwater sharks are among the most vulnerable to overexploitation because of an extremely low reproduction potential, even for sharks (Kyne and Simpfendorfer 2007)! The liver oil trade caused the collapse of the Gulper shark fishery in the Maldives, only 20 years after it started (Adam et al. 1998). The Portuguese shark ( Centroscymnus coelolepis) is also heavily targeted for their Squalene resulting in a declining overall abundance (OSPAR 2010).

The hydrocarbon compound that makes up Squalene can be extracted from other sources, such as palm oil, which can be obtained or farmed in a more sustainable method than the overharvesting of vulnerable deep-sea sharks.

Habitat Loss, Pollution and Environmental Degradation

Coastal development has increased significantly in the past century which has altered habitats, increased levels of pollution and resulted in the general environmental degradation in many areas. Many shark species use inshore coastal and estuarine habitats as a safe place for finding food, giving birth and growing up away from predators and competitors. This means that they are vulnerable to negative changes in their habitat. For example, dredging in the Bahamas resulted in a 25% decline in juvenile lemon shark survival (Jennings et al. 2008). Juvenile bull sharks have been known to be trapped in the warm water outfalls of power plants in Florida, USA, causing the sharks not to partake in seasonal migrations and if the water from the power plant does not flow, the sharks may succumb to thermal shock, thermal stress and may cause the sharks to cease seasonal migrations (Simpfendorfer and Burgess 2009).

Sharks are very susceptible pollution and environmental contamination. Pollution in the ocean has either filtered from land activities or has been directly deposited into the seas. As apex predators with slow growth, they accumulate all the pollutants and toxins in the environment and bioaccumulating all the toxins of their prey. Chemical pollution, in the form of mercury, DDT, organochlorines, etc., has been documented in several shark populations in close proximity to areas of human populations. Bull sharks in Florida have been found to have levels of pharmaceuticals that are disposed of through waste water discharge. But the effects of pollution are not just liited to the shark species that hang around developed areas. The Greenland shark is a deep water shark that likes remote locations of the colder seas. However, there have been high levels of contaminants found in these sharks, further evidence that pollution is a global problem.

Pollution is not only chemical, it can come in the form of discarded fishing gear and plastics that can entangle and injure or kill sharks and other marine life. Whether it is discarded plastic toys, a Frisbee has been found like a noose around a sharks gills, or miles of discarded longline filament, or gillnets that were lost by the fishermen, each poses a serious threat to sharks and many other marine species.

Shark Nets

Shark nets, also called beach meshing programs or beach protection programs, are essentially a form of shark fishing while supposedly providing bather protection. Shark control programs have been utilized in several places, including New South Wales and Queensland, Australia and KwaZulu Natal (KZN), South Africa.

Along Hong Kong beaches, the nets are designed to keep bathers separated from the sharks, a very expensive system to maintain. The controversy is whether shark control in any form is justified in a wild area where humans choose to enter while some believe it should be a case of "swim at your own risk". The Natal Sharks Board (NSB), responsible for the nets in South Africa, believes that the nets have done a remarkably good job protecting bathers. But at what cost?

The catch of this 'fishery' in KZN alone includes great white sharks (protected in South Africa since 1991), tiger sharks, hammerheads, turtles, dolphins, and rays, among other sealife and bycatch. The nets are a culling program, not a barrier intended to keep sharks away from bathers, as 35% of sharks caught in the net are headed off shore (Dudley 1995).

The shark nets were put into place in KZN in response to public outcry when several shark bites occurred over a few days in the 1950s. Once measures have been put into place, it is difficult to convince the tourism industry and the water-users that the nets are not crucial to their survival. The installation of shark nets reinforces our misguided and often times irrational fears of sharks, providing a very real example that our concerns are valid. This in turns fuels the biggest issue faced in shark conservation: public apathy or even loathing towards sharks.

The installation of shark nets reinforces our misguided and often times irrational fears of sharks, providing a very real example that our concerns are valid. This in turns fuels the biggest issue faced in shark conservation: public apathy or even loathing towards sharks. Socio-political pressure may make the removal of the nets difficult but awareness campaigns may educate the public about the detrimental impact the nets have on local and migratory sharks and other marine animals. There are better ways to protect swimmers that don't indiscriminately kill sharks and other marine life. Since the installation of these nets, we have learned so much about sharks and the dire status of their populations that there is no excuse to continue an archaic and destructive practice when it is well understood that the actual risk of an incident is slim.

Souvenirs

In some parts of the world, including the United States, money is made on the sale of shark parts as souvenirs. Some recreational fishermen target large sharks to make a trophy from the jaws, which can sell for hundreds of dollars. Since the meat from these large sharks is not edible, the rest of the shark is wasted. In other places, such as Mexico, souvenir jaws from all sizes and types of sharks, including baby sharks, can be found in tourist shops. Sharks' teeth are another popular item found at souvenir shops, as well as small or baby sharks in jars of formaldehyde.

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Tags: Threats, Environment There has been a lot of attention placed on the impact of commercial fishing on shark populations, which is well warranted considering the sheer scale of the catches. However, the overall impact of recreational fishing on shark populations is not well studied and is typically difficult to detect.

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The history of sharks goes back a long time. But the term "a long time" doesn't even begin to cover it. Let's put it this way: dinosaurs lived during the Mesozoic Era, which began about 245 million years ago. Sharks, on the other hand, were living on the planet 200 million years before dinosaurs! Is it starting to sink in now? Sharks are without a doubt one of the oldest creatures this planet has ever known.

Fossil Records

In order for scientists to determine information pertaining to the history of sharks in terms of age, appearance, and possible behaviors of ancient sharks, they study fossils. A fossil can be an impression of a prehistoric life form that has been preserved in a rock or mold. It can also be literal remains from the organism itself. Fascinatingly, shark fossils are extremely rare because sharks are mostly comprised of cartilage; cartilage tends to disintegrate too fast to become fossilized. For this reason, most shark fossils are prehistoric teeth, fin spines, and scales.

The Age of Fishes

During the Paleozoic Era, there was a period called the Devonian Period. The Devonian Period was first studied with a Devonian red sandstone found in an area called Devon, England; this is the reason why the period was named Devonian. This period is known for the development of thousands of ancient fish species. Interestingly enough, during these early stages of fish development, they did not have jaws, and their bodies were comprised of cartilage, like the modern day shark. Sharks also developed during this fishy period of earth. They are believed to be descendants of Placoderms, a group of ancient, jawed fish that possessed a dermal skeleton. Placoderms had what is considered armor covering their bodies. Although sharks are identified as descendants of this group, over time they have lost the ability to produce bone both internally and externally. The shark fossil records show that the earliest sharks began developing during the middle of the Devonian Period.

The Cladoselache Shark

In Cleveland, Ohio, 400 million-year-old shark fossils were found and studied. These fossils turned out to belong to an ancient four-foot long Cladoselache shark. As one of the first species of sharks, these Cladoselaches most definitely differ from the modern day shark, however they do have similarities. Like the sharks we see today, Cladoselache sharks had gill slits and torpedo-shaped bodies. Nonetheless, these sharks differ greatly from today's sharks, and even other ancient sharks because they did not have any placoid scales covering their skin. Sharks, both ancient and modern, are known for having tooth-like scales enveloping their skin; they not only protect the shark, but they also aid in swimming techniques. In addition to not owning placoid scales, these prehistoric sharks did not possess claspers. Claspers are usually present on male sharks, and they supply sperm for the female during reproduction. Due to the fact that Cladoselache sharks did not have claspers, it is actually unknown how they reproduced. They most definitely managed to reproduce and swim without claspers and dermal skin successfully, because Cladoselache sharks lived in Earth's waters for about 100 million years.

The Stethacanthus Shark

The Stethacanthus is a prehistoric shark that lived from 345 million to 280 million years ago. These two-foot long sharks preferred to swim in shallow, warm waters. This particular species of shark is actually quite interesting and often baffles scientists because of two factors. Firstly, the only sharks of this kind that have been detected all have claspers. This would mean that we only know of the male Stethacanthus. There is a type of shark called Symmorium, and the only sharks of that kind that we know of are female. It is possible that the Symmorium is actually the female version of the Stethacanthus, and therefore they mate with each other. Scientists are not completely sure of this, but it sounds very probable. In addition to this intriguing factor, the Stethacanthus shark possessed an exceedingly fascinating dorsal fin. This fin was in the same position as the dorsal fin of a modern day shark, however the top of it was flat and enamored in large scales. The appearance of this headgear is often compared to a brush. Even though we are unsure what these dorsal fins were used for, there are a few theories. One belief is that this headgear resembled jaws of a massive being, and therefore deterred any predators. Another theory is that this headgear was used to attract females when mating. Nevertheless, the Stethacanthus shark was without a doubt an intriguing specimen.

The Xenacanthus Shark

The three-foot long Xenacanthus shark existed 345 million years ago during the Devonian Period, and it lived until the Permian Period. These particular sharks were freshwater inhabitants that typically dwelled in rivers and lakes. The Xenacanthus owned V-shaped teeth that enabled them to eat bony fish and crustaceans. Although the Xenacanthus was most definitely a type of shark, its appearance closely resembled that of an eel. Xenacanthus sharks had an elongated, thick spine that extended throughout their bodies, starting from the back of their skull. It is believed that the spine of a Xenacanthus was used as protection against possible predators. Following this eye-catching spine was a dorsal fin that looked like a ribbon. The spine and dorsal fin of the Xenacanthus is the reasoning behind the shark's eel-like appearance.

Shark Evolution

The Cladoselache Shark, Stethacanthus Shark, and Xenacanthus Shark are three types of sharks that existed during the Devonian Period, and based on the look and behaviors of modern day sharks, they are proof that sharks have evolved tremendously over time. The sharks of today all have tooth-like placoid scales covering their skin, and they are made up of cartilage. In addition, the fins and gill slits are relatively similar throughout most of today's shark species. These factors differed greatly during the beginning days of the shark. Interestingly enough, however, the history of sharks hasn't changed much for 100 million years. During the time when dinosaurs roamed the earth, the shark families had already evolved to the type of sharks we are accustomed to seeing today.

Page Created By: Mike Rogers
From History of Sharks to The Shark Sider Homepage

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Cool Information About Sharks In A Short History - Shark Sider

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The history of sharks goes back a long time. But the term "a long time" doesn't even begin to cover it. Let's put it this way: dinosaurs lived during the Mesozoic Era, which began about 245 million years ago. Sharks, on the other hand, were living on the planet 200 million years before dinosaurs!

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The megalodon shark (Carcharodon megalodon) was a massive being that would put modern day sea predators to shame. If you are currently afraid of the great white shark, then I'm sure you're happy that you don't have to worry about the megalodon creeping up under your sailboat. This colossal being was not one to mess with, and although the megalodon is now extinct, its memory most definitely deserves to be respected and well known.

How scientists know about this giant prehistoric beast

Just like the sharks of today, these sharks were comprised mainly of cartilage. So even though these sharks were immense, the majority of their bodies were not fossilized; cartilage usually disintegrates too fast for the fossilization process to occur. Therefore, there are still many factors of the megalodon that we are unsure of. Luckily, some teeth have been found and investigated. Because of this, paleontologists have managed to uncover quite a few facts about these amazing creatures, and although many specifics are still being debated, there are a few things that most are definitely in agreement on.

Megalodon Shark On Shark Week

Widely accepted facts

From 70 million to 10 million years ago, the wonder known as the megalodon shark ruled the warm waters of Earth. Based on what researchers have discovered, the megalodon had many physical and behavioral similarities to the great white shark; however, one of the main differences between the two was that the megalodon was substantially more menacing and intimidating. The average great white can be anywhere from 15 to over 20 feet (4 to over 6 m) long. Yes these lengths are pretty impressive, but it does not even compare to the megalodon shark. The exact lengths of these ancient sharks are still in discussion, however, we do know that the megalodon was approximately 40 to 70 feet (12 to 21m) long! They are also known as the "megatooth" shark and was the largest carnivorous fish that has ever existed on Mother Earth.

Scientists have studied megalodon teeth that were found in Africa, North America, South America, India, Australia, Japan, and Europe. Based on the locations that these teeth were unearthed, it is the firm belief that they thrived in the world's warmer waters. As mentioned earlier, scientists are still trying to uncover particulars of this prehistoric shark, including their diet. Since the great white shark is a descendant of the "megatooth" shark, most believe that the diet of the great white shark reflected that of the megalodon. However, based on the serration marks found on the "mega" teeth of the ancient shark, it is believed that they also fed upon whales.

A possible reason for extinction

Yes, the megalodon shark is extinct. Unfortunately, due to the fact that not much information has been determined regarding these incredible beings, the absolute reason of why they all died off is unknown. There are a few theories that would explain the extinction of these animals, however. Two of the main speculations actually coincide with the belief that these sharks swam in warm waters. During the time when these sharks were still living, the temperature of the oceans began to decrease. The oceans' steadily increasing colder temperatures may very well be what killed off the megalodon shark. Another plausible belief is that the ancient shark's preferred prey began to migrate to colder waters. These low temperature waters were probably too cold for the megalodon to survive.

Is the Megalodon Shark still alive?

Interestingly enough, there are many who refuse to believe that the megalodon shark is indeed extinct. Skeptics feel as if the megalodon shark may possibly be in existence deep down in the ocean. While it is true that we have not explored every inch of the world's oceans, and it is likely that there are undiscovered species living in the depths of the waters, the belief that the megalodon shark may still be alive today has yet to be proven. Sharks are known for shedding hundreds of teeth on a regular basis; if the megalodon shark was still alive, they would be expected to shed the most teeth out of all of these sharks. Every megalodon tooth that has been found is ancient. Until a fresh megalodon tooth, a "megatooth" shark sighting, or some other form of proof has been presented, it is determined that this ancient shark is most definitely extinct.

Page Created By: Mike Rogers
From Megalodon Shark to Types of Sharks From Megalodon Shark to the Shark Sider Homepage

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All Your Megalodon Shark Facts And Stats Are Here - Shark Sider

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The megalodon shark (Carcharodon megalodon) was a massive being that would put modern day sea predators to shame. If you are currently afraid of the great white shark, then I'm sure you're happy that you don't have to worry about the megalodon creeping up under your sailboat.

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All About Sharks for Children: Animal Videos for Kids - FreeSchool

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Boats and boating--Equipment and supplies

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A great white shark captured by a Japanese aquarium died Friday after just three days in captivity, the aquarium announced.

"We are going to announce termination of [the] Great White Shark exhibition. We had ... displayed the shark in 'the Sea of dangerous sharks' tank from January 5th, 2016 but, the shark's condition took a sudden turn [for the] worse and we confirmed its [death] January 8th."

The species doesn't do well in captivity. This 11.5-foot-long male refused to eat, the Associated Press reports.

"An official for People for the Ethical Treatment of Animals, or PETA, Asia, criticized keeping the shark in captivity as 'cruel and wrong.'

" 'The cause of death is clear: captivity. The shark never had to die like this,' said Jason Baker, PETA's vice president of international campaigns."

The Monterey Bay Aquarium near San Francisco is the only one in the world to keep a great white shark for more than a couple of weeks, the Monterey Herald reported. The aquarium at various times since the mid-'80s has put a half-dozen great whites on display, the longest for nearly 200 days in 2004 and 2005, the Herald wrote.

But even for the Monterey aquarium it's been difficult. The Herald reported that the first attempt in 1984 ended when the shark refused to eat, dying after 11 days in captivity. And while its most recent shark - exhibited in 2011 - was released after two months in captivity, it died just minutes later, the aquarium said.

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Great White Shark Dies After Just 3 Days In Captivity At Japan Aquarium

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A great white shark captured by a Japanese aquarium died Friday after just three days in captivity, the aquarium announced. "We are going to announce termination of [the] Great White Shark exhibition. We had ...