These giant sharks are 3 times as tall as a giraffe – and can lurk for 130 years, research finds
The largest fish in the sea can be found off the coast of the Carolinas — an enormous shark.
Whale sharks are the largest known fish species in existence today, but new research suggests the sharks can grow even larger than previously thought and can live more than a century.
Scientists observed whale sharks 18 feet to 40 feet or longer, and calculated that they lived to be about 70 years old on average, according to National Geographic. They can weigh more than 20 tons.
New research in the Maldives, published in the Marine and Freshwater Research journal this week shows whale sharks can grow even larger and live much longer than previously thought.
Whale sharks are an endangered species whose growth and reproduction are poorly understood, according to the research.
Traditionally, the size of whale sharks had been determined using vertebral samples from dead animals, but that was limiting for research purposes.
So the group of researchers used noninvasive techniques to investigate the growth of whale sharks in the South Ari Atoll, Maldives, an area that may be a nursery ground for the sharks.
Scientists analyzed repeat measurements of free swimming whale sharks over a 10-year period.
Total lengths of the sharks were estimated using three methods: visual estimates (which often underestimated the size of the sharks), and laser and tape measurements, which yielded similar results to each other.
After hundreds of shark encounters, researchers estimated that the sharks can live to be 100 to 130 years old and can grow between 50 and 62 feet long at those ages.
“This study suggests that, like some other shark species, we may have been underestimating age by quite a bit,” said Alistair Dove, a marine biologist and conservationist at the Georgia Aquarium. “We used to think whale sharks lived to be 75 to 100.”
But these numbers only show that more research about whale sharks is needed to better understand them.
“Differences between these estimates and those from other studies, underscore the need for regional studies,” the research concluded.
The research paper, “Comparing length-measurement methods and estimating growth parameters of free-swimming whale sharks” was authored by Cameron T. Perry, Joana Figueiredo, Jeremy Vaudo, James Hancock, Richard Rees and Mahmood Shivja.
Whale sharks are listed as a vulnerable species, with a declining population, according to the International Union for Conservation of Nature. Even though their numbers are decreasing, whale sharks still are hunted in parts of Asia, including the Philippines.
Fortunately for most oceangoing creatures and those that visit the ocean occasionally — like people — whale sharks’ favorite food is plankton, which they scoop up in their colossal, gaping mouths while swimming near the surface.
Whale sharks are also typically docile, sometimes allowing swimmers to hitch a ride.
There are several private companies that take visitors to swim with sharks off the coast of the Carolinas, and whale sharks are among those spotted.
Whale sharks have enormous mouths that can open up to nearly 5 feet wide, with 350 rows of tiny teeth, according to the Fisheries and Aquaculture Department of the United Nations.
The sharks have flattened heads with blunt snouts and short barbels protruding from their nostrils. They are gray to brown on their sides, with white spots along with pale vertical and horizontal stripes. Their bellies are white.
Whale sharks usually prefer warmer waters, which means they can be popularly found in tropical seas, but they can be found along coastlines around the world, including the East Coast of the U.S.
source: https://www.heraldsun.com/latest-news/article214772230.html
By freedivinguae