May 25. According to the excerpt from the press release issued by the Smithsonian National Zoological Park, off the coast of the Yucatan Peninsula in Mexico, there were about 420 whale sharks, thus forming the largest in number of sharks flock of this species.
This news is contrary to popular belief that whale sharks, weighing more than 79,000 pounds (30 tons — annotated. Translator), alone feed on plankton, and prefer solitary swim in the open ocean. Such an impressive gathering of sharks indicates the presence of a great cause. At the moment, this cause is the presence of food.
"Whale sharks — the largest marine life in the world, but they are still mostly eat tiny organisms in the ocean, such as zooplankton," — said Mike Meslenka — a biologist from the Smithsonian Institute for the Conservation of Biodiversity and the head of the Department of healthy eating. "Our research shows that in this case the whale sharks gathered eat caviar large clusters."
Meslenka and his team identified a large concentration of whale sharks through the use of aerial and surface assessment. Taking into account the fact that sharks can grow to over 40 feet, surface method is given the highest preference.
Despite their enormous size, whale sharks are not aggressive and move very slowly. Usually notice them in the ocean floating in anticipation of food with open mouths to 1.5 meters wide. These sharks are found in tropical and subtropical areas of the ocean around the globe.
Researchers call the huge accumulation of sharks "Afuera"-cluster. Part of the study was to use special traps to collect food samples inside and around the shoal feeding whale sharks. According to test results became known that the object of desire of the sharks are small tuna roe (Latin name — Euthynnus alletteratus), a member of the family scombers.
"Having DNA barcoding is an incredibly valuable tool for the study," — says Veigt Lee, head of the Laboratory of Analytical Biology at the Smithsonian National Museum of Natural History. "It is not only possible to find out what exactly was fed a huge cluster of sharks, but also revealed a previously unknown spawning small tuna."
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In addition to the "Afuera" scientists discovered another, less abundant collection of whale sharks from the northern tip of the Yucatan Peninsula. This second collection called Cabo Ketoche-cluster. In this area, the bait for sharks, mainly served as small crustaceans and shrimp. Both groups of sharks were about the same sex ratio, which indicates that all the sharks of the family should be "heard" dinner bell part of Nature.
"In two important areas clusters of whale sharks and at least one active spawning ground for small tuna, northeastern Yucatan in this marine region is a critical habitat that deserves more concerted efforts to preserve it," — concludes Meslenka, noting that the whale Sharks are considered by the International Union for Conservation of Nature "vulnerable," primarily because of the use of spear fishing in South-East Asia and probably are also subject to other fisheries.