Like many fish sharks also have another sense, a sixth sense, which we don’t know much about. They are able to detect tiny electrical impulses in the water. As all animals produce some electrical signals this can be very useful! They can detect movement in the water from hundreds of meters away. They can pick up electrical signals generated by their prey, making it possible to feel other animal movements.
This sixth sense is made possible thanks to electro-receptive organs called Ampullae of Lorenzini. These were discovered only recently. The Ampullae are jelly-filled pores. These pores are located all around their heads with a greater concentration around their snouts and are connected to the brain through nerve endings. Basically, these ampullae are electrical field-sensing devices. Every living creature produces an electrical field which sharks can detect.
Strangely enough, a shark will sometimes attack a metal object. This is because, in salty seawater, metal gives off electric signals, which confuse the shark into thinking it is prey. This means a shark cannot only detect its prey but a diver or potential hunters without seeing them.
Shark is a kind of fish that is protected. You can find them on places like sea world. They take care sharks, of course unlike birds, dogs, cats or goldfish, sharks have special needs. Got interested with shark and other fish? Well you should, because fish are fantastic animals and you can have them as your pets.
Filed under Sharks Knowledges · Tagged with amp, Ampullae, angel, animal, animal movements, brain, cannot, car, care, cent, Co, concentration, course, creature, diver, dog, dogs cats, Don, electric signals, electrical field, electrical signals, EST, field, fin, fish, gel, gene, goldfish, Got, Great, head, kind, kind of fish, Lorenzini, mean, metal, movement, need, nerve, nerve endings, object, organs, place, potential, prey, protect, range, rat, rate, ratio, Red, rest, round, sea, sea world, seawater, sense, sensing devices, shark, Sharks, signal, sixth sense, snouts, special needs, Strangely, time, tiny electrical impulses, US, use, water, way, With, world, Your
we know that sharks live in wilderness. the ocean is a wet jungle and shark is one of predator that is unique and endangered species. it’s not like other fish, shark has become a great influence in human businesses. the researches and entertainments found that shark is very unique and has high commercial value. we find many movies with shark in them and it’s still attracted us to go to cinemas watching them. the researches about shark has develop into various aspects, even such as cosmetics and food.
for some people,shark is described as power and speed. it represents what we want to be. and some people try to keep sharks as their pets. nowadays researches help us to keep shark in special conditions, and put shark on aquarium isn’t difficult for now. but, imagine that you have a huge aquarium at your house with a shark in it. it looks cool ,but soon we will find it’s ridiculous. shark is no longer happy in that condition.
some of us have cats, birds, dogs and other small pets in our house. if you have shark in your house,then you are supporting shark’s extinction. to keep the shark live,we need the biggest aquarium on earth,that is ocean. the ocean provides the shark’s needs,including food and shelter. we can only observe them and leave them live peacefully. the shark is one of ocean’s wonders that we must keep in order to show our pride to the next generation of humankind.
Filed under Sharks Knowledges · Tagged with BSE, business, Co, Conditions, day, dog, ear, earth, Endangered, EST, Extinct, extinction, fin, fish, food, gene, Great, influence, kind, need, ocean, order, power, rat, ratio, Red, research, sea, serv, shark, Sharks, Species, such as cosmetics and food, support, thing, US, use, value, wild thing, wilderness, With, Your
- Sharks and rays have a very varied diet. They are carnivores which means that they eat animals rather than plants and algae. Some sharks commonly eat bony fishes, crustaceans (crabs, lobsters, and other animals with an external skeleton), mollusks(snails, sea slugs, octopus and squids), and different types of worms.
- A shark’s diet is often determined by its habitat. For example, sharks that live out at sea (pelagic sharks) are more likely to eatfish and squid because that is all that is available.
- Sometimes sharks change their diet as they get older. The Great White Shark mainly eats fish when it is young but once it reaches maturity it consumes more marine mammals like seals and sea lions.
- Most sharks prefer live food but they will also consume carrion (dead fish and other animals) that they find on the sea floor.
- Just like filter feeding whales, there are a few sharks that live by filtering plankton from the water. The filter feeding sharks may consume phytoplankton (microscopic plants and algae) while hunting for more nourishing zooplankton (tiny animals and larvae that drifts around on the currents). Ironically, the Whale Shark which is the largest fish in the sea, lives on plankton which is one of the smallest animals. So does the second largest fish; the Basking Shark. Although these sharks have huge mouths, their throats are tiny and they are unable to eat anything larger than a grapefruit. Their teeth which are no longer needed for feeding, have become very small.
- The largest ray (the Manta Ray) is also a plankton feeder. It has a flexible projection on each side of its mouth called cephalic lobes that it uses to funnel plankton towards its mouth.
- Most rays eat small fishes and benthic invertebrates; crabs, snails, and worms etc. that live on or under the sand.
- Sometimes its possible to tell what type of food a shark eats by the shape of its teeth. Sharks that catch fast swimming fishes tend to have very pointed teeth that help them grasp the fish. Sharks that eat hard shelled animals have flattened teeth that form a plate to help them crush the creature’s shell like a nutcracker.
- Tiger Sharks have a reputation for eating anything. They have been found with all sorts of strange things in their stomachs from clothes to license plates. Tiger Sharks have very sharp serrated teeth that are strong enough to bite through the shells of marineturtles.
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The South African based White Shark Trust is “a non-profit organization founded in 2002 to promote and conduct research, education and conservation projects on the endangered Great White Shark”
It is the brain child of Michael Scholl (founder and trustee) who has been conducting research on Great White Sharks since 1997.
The goals of the White Shark Trust are as follows:
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To establish a fund in the Republic of South Africa for the purpose of receiving grants and donations from international sources as well as sources within the Republic of South Africa;
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To manage and disburse such funds in the furtherance of the objectives of the Trust;
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To promote dialogue between various research, conservation, education and Government bodies concerned with management, research, conservation and education concerning the Great White Sharks (Carcharodon carcharias);
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To assist in providing relevant advice on the management of the Great White Sharks (Carcharodon carcharias);
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To obtain the support for the objectives of the White Shark Trust from local residents living around concentration hotspots for the Great White Sharks (Carcharodon carcharias), including Mossel Bay, Dyer Island / Gansbaai and False Bay in particular;
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To obtain the support for the objectives of the Trust from the established tourism industry involved with the Great White Sharks (Carcharodon carcharias) located at Mossel Bay, Dyer Island / Gansbaai and False Bay in particular;
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To ensure that effective action is taken in all matters affecting the welfare and preservation of the Great White Sharks (Carcharodon carcharias);
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To promote educational opportunities for the general public, schools and the tourism industry;
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To conduct and support scientific research projects and field expeditions with regards to the Great White Sharks (Carcharodon carcharias).”
In connection with other like-minded South African organizations, the work of the White Shark Trust is of primary importance in order to better understand the critical role that White Sharks play in balancing the marine environment. Without their joint efforts we are unable to identify the need for better shark protection.
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The shark existence of the east coast of the USA decreased in the last 15 years substantially. The number of the hammerhead sharks sank around 89%, those of the thresher sharks around 80%, those of the great white sharks around 79%. The populations of the mako sharks, blue sharks and tiger sharks sank around 40-65%. The existence of the sandbar sharks were reduced in the last 10 years by overfishing by 85-90%.
Canadian researchers announce a decrease of the oceanic whitetip shark by around 99%. They are almost extinguished in certain regions already.
Sharks are not only caught actively for their meat, fins or cartilages. Millions of sharks die as non-usable catch (bycatch) in the nets and longlines of the swimming fish factories.
In the year 1991 the longline fishery brought in 8.3 million sharks world-wide. It is assumed that about half of it were blue sharks. More than 87% of these 8.3 million sharks were thrown away!
In the USA, along the Atlantic Coast and the Gulf of Mexico, annually approx. 2.5 million sharks are fished by sportfishing (game fishing). From that approx. 20-40% (500’000 – 1’000’000 sharks) got killed.
The population of all sorts of sharks is worldwide extremely threatened. In total 82 shark and ray species are registered on the so called “Red List” of the World Conservation Union.
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