mapa de distribucion mundial del tiburon blanco 2012 distribution world map of white shark

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como son los dientes del tiburon blanco y sus antecesores

Los dientes aserrados del Carcharodon carcharias

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Hace seis millones de años, un temible tiburón blanco de afilados dientes aserrados, acechaba en los mares del Atlántico sur. Sin embargo, por razones que aún se tratan de establecer, restos de aquel ejemplar fueron hallados por un equipo de paleontólogos del Museo de nuestra ciudad, encabezados por el doctor Alberto Luis Cione, en una localidad cercana a lo que actualmente es el río Paraná, en la hoy provincia de Entre Ríos.
“Hay dos hipótesis sobre cómo este ejemplar hallado pudo haber llegado a la zona donde hoy está el río Paraná -explicó el doctor Cione, investigador del Museo de La Plata y del CONICET- una posibilidad es que haya pasado al océano Atlántico por el área actualmente ocupada por Panamá, porque Centroaméricay Sudamérica estaban separadas durante el Mioceno tardío y había una vía de paso entre ambos océanos para los animales marinos”.
“El itsmo se comenzó a completar hace unos tres millones de años -añadió el paleontólogo especializado en el estudio de los peces- permitiendo la migración de animales terrestres y el denominado gran intercambio biótico interamericano, al punto que el guanaco, por ejemplo, tan asociado simbólicamente a Sudamérica, tuvo su origen en el norte del continente”.
Y como hace seis millones de años el nivel del mar era más alto, fue posible que este gran tiburón nadara hasta donde hoy está el río Paraná, porque en esa época la llanura pampeana y parte de Entre Ríos estaban cubiertas en gran medida por aguas saladas.

Geographical Distribution The white shark is cosmopolitan but occurs mostly in temperate seas

Geographical Distribution

The white shark is cosmopolitan but occurs mostly in temperate seas, with large individuals known to penetrate tropical waters. It makes sporadic movements to cold, boreal waters and has been recorded off Alaskan and Canadian coasts. It occurs in the western Atlantic from Newfoundland to Florida, the northern Gulf of Mexico, the Bahamas and Cuba as well from Brazil to Argentina and in the eastern Atlantic from France to South Africa, including the Mediterranean. In the Indian Ocean, it occurs in the Red Sea, off South Africa and the Seychelles Islands, as well as Reunion and Mauritius. In the western Pacific, it ranges from Siberia to New Zealand and the Marshall Islands, off the Hawaiian Islands in the central Pacific and from Alaska to the Gulf of California and Panama to Chile in the eastern Pacific.

tiburon blanco bajo el agua video de alta calidad

nadando sin jaula con el tiburon blanco

SHARK ATTACK 3 (THE ACTUAL FULL MOVIE)

http://www.youtube.com/watch?v=Msk7-9TPo7Y

La fisiología del gran Tiburón blanco

Circulación. En el sistema circulatorio del hombre son las arterias las que llevan la sangre desde el corazón a todo el cuerpo y las venas, desde los vasos capilares de todo el cuerpo, al corazón. La circulación de los tiburones es diferente.

Taxonomy and Evolution of The white shark was not always known as Carcharodon carcharias

The white shark was not always known as Carcharodon carcharias. Since 1758, when it was named Squalus carcharias, this species has been afforded a variety of scientific names, including Carcharias lamnia Rafinesque 1810,Carcharias verus Cloquet 1817, Carcharodon smithii Bonaparte 1838, Carcharodon rondeletii Müller & Henle 1839,Carcharias atwoodi Storer 1848, Carcharias maso Morris 1898, and Carcharodon albimors Whitley 1939. The genus name Carcharodon is derived from the Greek "karcharos" = sharpen and "odous" = teeth. The species name carcharias, also translated from Greek, means point or type of shark, leading to its common name in Australia of the white pointer.

Cladograms of proposed generic relationships in the family Lamnidae, adapted from Klimley & Ainley (1996)

The relationships between the white shark and the other genera of its family are controversial. Two phyletic arrangements have been proposed. One suggests it is more closely related to the mako sharks (genusIsurus) (figure A), while the other proposes it remains closer to the porbeagle and salmon sharks (genus Lamna) (figure B). Recent studies indicate that the first hypothesis is best supported but does not refute the second one.

Studies indicate that the white shark and the other genera of its family may have originated in the Paleocene or early Eocene. Fossil registers indicate that, in the late Cretaceous and Paleocene, the lamnid sharks (sharks from the family Lamnidae) were abundant and diverse. The evolution of the white shark also presents various theories. One proposes that it evolved from the megatoothed line of sharks, and another suggests that it evolved from a Miocene mako shark.

atraccion hinchable de tiburon blanco

¿Cómo se rodo la escena de tiburon cuando el tiburon monta encima del barco?

 

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¡Que nadie se lleve las manos a la cabeza antes de tiempo! La fotografía que encabeza este artículo no ha sido tomada en el preciso momento en el que un enorme, un gigantesco, un descomunal tiburón blanco se come vivo a un pobre pescador tras hacer trizas la pequeña embarcación en la que instantes antes se hallaba, caña de pescar en mano, esperando que algún lindo pececito picara 

Es más, la instantánea no es actual. Como las otras que incluyo en este artículo tiene 38 años. Fuerealizada en 1974 durante el rodaje de la mítica película Tiburón que dirigió Steven Spielberg y en la que contó con un brillante elenco de actores entre los que destacaron con luz propia Roy Scheider, Richard Dreyfuss y Robert Shaw.

El bicho que aparece no es por tanto un tiburón blanco de carne y hueso, sino uno de los 3 escualos mecánicos que el equipo de efectos especiales creó para rodar las escenas submarinas y que tantos problemas generaron a los técnicos encargados de su mantenimiento durante el rodaje.

Megalodon vs Predator X (remade) requiem for a dream

imagen aerea de surfero muy muy cerca de tiburon blanco a menos de 20 metros

tooth size comparation different white shark

the underwater wildlife species on our planet, the great white shark is perhaps the most feared by humankind

Of all the underwater wildlife species on our planet, the great white shark is perhaps the most feared by humankind. For 15 million years that have roamed our world's oceans, continuing to evolve in brilliant force to be the apex predator of the sea. Although so few, great white shark fatal attacks spark massive media attention in papers and TV forums around the world. And of the 63 fatal attacks ever recorded in the history of human deaths, 27 of these have occurred in our home country of Australia.

The fear of being eaten alive is undoubtedly very high on the list of worst ever nightmares - not just for the victim, but for the family and friends left to deal with the horrific loss of a loved one. In order to resist such occurrences, so few and far in between, certain Political Parties insist on exploring the option of netting popular swimming beaches and monitoring our coastlines with shark spotter planes. The facts regarding these options though are usually ignored. The netting system (in NSW and Queensland for example) is responsible for killing a multitude of native wildlife. Thousands of dolphins, sea turtles, stingrays, other species of sharks and thousands of ocean going fish are killed when they get stuck in the nets and drown.

As for the spotter planes, the cost of running such an operation means thousands of dollars in taxpayer's money. The spotter planes do indeed spot sharks, but what sort of sharks actually are they? Do the reports mention the species of shark? (It could be a 1 metre long bronze whaler). Do they mention if it's the same shark they actually spot more than once on their coastal laps? And most importantly, do they mention the distance the shark is away from the coastline?
With 27 deaths recorded in the history of great white shark fatal attacks in Australia, the question has to be asked, is it actually worth all the fuss?

Delving into the study about where white sharks travel and how many there actually are in our waters, is CSIRO great white shark scientist, Barry Bruce. Based in Hobart, Tasmania, Barry has been studying the movement patterns of white sharks for over 20 years. His research has often taken him to the Neptune Islands, 70 kilometers out to sea from Port Lincoln in South Australia. Resident on these islands is colonies of New Zealand Fur Seals, attracting hungry great white sharks that pass through the area. Calypso Star Charters is 1 of only 2 cage-diving tourism operators in Australia that hosts international tourists wanting to see the impressive giants up close in the flesh. Working closely with Barry Bruce is Calypso's skipper, Rolf Czabayski, a game fishing world record holder for catching one of the largest white pointers on one of the lightest lines. Rolf himself has been involved in the tagging program and is responsible for independently tagging over 300 of the 500-tagged white sharks in Australian waters. Since the year 2000, Barry, with Rolf's assistance, has also attached 8 satellite tags to white sharks and the result of their research has been amazingly extensive.

The white sharks tagged in South Australia, travel up to 80 kilometres in a single day and are the same great white sharks spotted in Tasmania, Victoria, New South Wales, Queensland and Western Australia. Its not that there are white pointers all over Australia, it's the same group of white sharks that are found everywhere. They usually travel on their own but take almost identical underwater pathways arriving at the same locations but at varied times throughout the year. Great whites are more common to pass by the Neptune Islands in winter, and once the seals have finished puppying, move up the east or west coasts of Australia in search of different food. The migration of humpback whales up both coasts of Australia attracts white sharks, as does the calving of Southern Right Whales near Nullabor in the Great Australian Bight. Seal colonies and baby whales however, are not the only food source for white sharks. Large ocean going fish such as tuna and salmon, dolphins, stingrays and other species of sharks also fall quite high on the white sharks diet and is believed to be the reason they may occasionally venture closer to our shoreline.

Once they've traveled around during the seasonal changes, some of the white sharks will return back to the very same spot they left from a year earlier for a returning food source, such as the next seal puppying season at the Neptune Islands. And its this high mobility data that leads us to believe that there are actually fewer great white sharks out there than we realise because they are all the same ones. Even on an international scale, the distance that white sharks travel continues to unfold. One white shark that was tagged in South Australia was the same shark that was later spotted in New Zealand. This is the only occurrence of a white shark tagged in South Australia that has gone outside of Australian waters. But recently, a white shark tagged in South Africa showed up near the North Western Shelf of Western Australia. Interestingly, at the same time of year, that other white sharks go to in the summer months. As to why they choose to go here in the summer months is a mystery, though its more than likely related to a food source.

Other interesting data from Barry Bruce's research aboard Rolf's boat involves white shark reproduction and how big they actually get. The Neptune Islands sees some of the most smallest and largest of great white sharks, which brings Barry to believe that reproduction must happen near this area. Unknowingly to many, one of the major reasons white sharks are a protected species in Australian waters is because of their poor ability to reproduce their numbers. The females don't start reproducing until they're very big - until they're 5 metres in length and they don't reproduce every year. It's quite possible that they only reproduce 1 in every 3 years. And unlike other ocean species that reproduce very large numbers at a time such as snapper or brim, white sharks only produce up to 10 pups. These pups when born, are 1.5 metres long, hence the necessary large size of the birth mother, and like any new born in wildlife, not all of those will survive. Once born, the perfectly developed little white sharks grow at a rapid rate of 30cm per year until they're 3 metres in length. Their growth rate then slows down with males expecting to reach maturity at 7-9 years of age at a length of 3.5 to 4 metres. The females mature later than the males at 12-17 years of age at a larger length of 4.5 to 5 metres. The largest white shark measured in the scientific community is 6.1 metres but scientists believe they may grow up to 7 metres in total length, weigh up to 3000 kilos and can live up to 60 years of age.

Their poor ability to reproduce however, leads Barry to believe that the birth rate of white sharks now equals their natural death rate, making them a very vulnerable species, and humans' influence on their population status, potentially devastating.

Suddenly, more than ever before, humans effect and influence on a creature that we fear so much, is vital. In Australia, the great white shark is generally misconceived as a ruthless killer with many people questioning the safety of our beaches. Overseas however, great white sharks are more of a positive tourism draw card than an ignored asset. In South Africa, cage-diving tourism operators are in the dozens, giving thrill seekers the opportunity of a lifetime to see a great white up close. Calypso Star Charters, though only 1 of 2 operators here in Australia, also run a very successful business, which attracts tourists from all around the world. Our water here is very clear and you don't need to have your scuba diving license to experience the cage. Rolf Czabayski has been running his tourism operation since 1990 and he says the reactions on the faces of people who experience the thrill of seeing great white sharks, is simply, "unbelievable"

Unfortunately, for the great white shark though, the rare accidental fatal attack on human beings continues to override the actual statistics and facts. Truth is, despite the millions of hours people spend in the ocean, you're 5 times more likely to get struck by lightening than suffer the jaws of a white pointer. With careful consideration of the facts, perhaps we can begin to see white sharks in a different light. The great white shark is a traveler. It is an iconic and magnificent species. It is playing a vital role in what is the nature of our open oceans. Fearing them is acceptable, but they have been protected for a reason. Lets keep it that way.

video tiburón blanco juvenil salta a un barco Juvenile white shark video jumps to a boat Juvenile white shark Video springt auf einem Boot

Tiburón blanco salta en un barco

Increíble video donde un tiburón blanco juvenil salta a un barco, donde permanece un tiempo para pasmo de los turistas.

foto de tiburon blanco muerto gran tiburon blanco muerto en la playa

great white shark dead on shore

imagen de mordida del tiburon blanco en la parte de los gemenos de una pierna humana / picture image of white shark bite in the share of a human leg gemenos / picture

No se preocupen, aunque es posible cada vez será más difícil que le muerda un tiburón. Un reciente trabajo, publicado en la revista Conservation Biology, desvela que cinco de las 47 especies mediterráneas de tiburón han perdido entre el 96% y el 99,99% de su población en los últimos 200 años. En concreto, los investigadores han analizado el declive del tiburón martillo, la tintorera, el marrajo común, el tiburón zorro y el marrajo sardinero.

La disminución de las poblaciones de estos tiburones se debe a la captura no intencionada en pesquerías en mar abierto, la pesca específica y la presión humana en zonas costeras. El estudio revela que cada vez se capturan más tiburones que aún no han llegado a la madurez.

imagen de surfero en la cresta de la ola con sombras de dos tiburones blancos al acecho

what do you draw a white shark?

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