Shark’s Electroreception
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
Shark Existence
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.
Filed under Save Sharks · Tagged with age, approx, Atlantic, Atlantic Coast, blue, blue sharks, bycatch, canadian researchers, car, cartilage, catch, Co, coast, conservation, decrease, ear, existence, fact, fin, fins, fish, fish factories, fishery, fishing, game, game fishing, Got, Great, great white shark, great white sharks, Gulf of Mexico, half, hammerhead, hammerhead sharks, head, line, List, longline, longline fishery, longlines, mako, mako sharks, meat, number, ocean, oceanic whitetip shark, overfishing, population, ray, Red, region, research, researcher, round, row, sand, sandbar, sandbar sharks, sea, serv, shark, Shark Existence, shark existence of the east coast, Sharks, Sharks are fish, Species, sport, swimming, threat, Threatened, thresher, thresher sharks, tiger, tiger shark, Tiger Sharks, Union, US, USA, way, White, white shark, white sharks, whitetip, Wide, world, world conservation union, worldwide, year, year 1991
