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Whale shark has set a record for the range of migration

Sam Farkas / NOAA OAR 2014 Photo Contest

Marine biologists recorded the migration of a whale shark with a range of 20142 km. As the researchers write in an article published in Marine Biodiversity Records, a female named Anna sailed from the shores of Panama to the Mariana Trench (in a straight line it is 13.8 thousand kilometers). This is a record in the range of known migration among whale sharks in particular, and sharks in general.

Whale sharks ( Rhincodon typus ) are the largest animals on the planet with the exception of cetaceans. The maximum recorded length of the whale shark is 12.65 meters, and the weight is 21.5 tons. They are rather slow swimmers: according to the researchers, their speed reaches 67 kilometers per day. Whale sharks live in tropical and subtropical ocean waters and feed on plankton, small fish and cephalopods. It is known that they have “favorite” places, where there are large concentrations of these fish. Apparently, whale sharks are viviparous (once a shark was caught pregnant with 300 embryos), but as they are mating and childbirth is still unknown. Presumably, whale sharks reach puberty by the age of 30, and live up to 70-100 years.

Since little is known about these fish, researchers believe that studying their migration will identify potential feeding areas, mating and breeding grounds and sea “corridors” that sharks use for migration. Until now, the largest recorded distance that a whale shark has sailed is 13 thousand kilometers. They overcame them from the Gulf of California to the Marshall Islands in 37 months. But the authors of the article describe a new record.

Marine biologists from the United States and Ecuador, led by Hector M. Guzman of the Smithsonian Institution, installed three female whale sharks on September 16, 2011, satellite transmitters that transmitted data on the temperature of the water and the coordinates of the fish’s location. The sensors did not transmit the depth on which this or that individual was located, and were unable to work at great depths.

As a result, scientists traced the most distant migration of the whale sharks, which lasted 841 days (about 2 years and 3 months); then the sensor stopped signaling. The female named Anna “started” in the Panamanian coastal waters, sailed near the island of Cocos and turned south to the Galapagos (near the island of Darwin, which belongs to the archipelago, there is a place of whale sharks). Near the island of Clipperton, a shark hit the North Passach Current and, apparently, swam along it.

In April 2012, the shark trail was lost, but after 235 days the sensor began to signal already near the Hawaiian Islands. In December 2013, Anna swam to the Mariana Islands. The last 112 days while the transmitter was working, she was in the Mariana Trench area. In total, the shark swam 20,142 kilometers (the distance between the “start” and “finish” in a straight line is 13.8 thousand kilometers).

According to researchers, this is not only the most distant known migration of whale sharks, but also a record for sharks in general. Before that , a white shark journey was recorded , which lasted nine months, and during this time it sailed 20 thousand kilometers.Earlier, the record for the range of migration was supplied by a female gray whale, which crossed the Pacific Ocean from Sakhalin to the coast of North America and back, eventually overcoming 22.5 thousand kilometers.

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