SYDNEY, Sept. 16 (Xinhua) -- A decade-long study of whale sharks, the world's largest fish, finds that female whale sharks grow slower than males but end up being larger.
Published in the journal Frontiers in Marine Science on Wednesday, the study first revealed while male whale sharks grow quickly before plateauing at an average length of about eight or nine meters, females could reach 14 meters over time.
"But even though they're big, they're growing very, very slowly. It's only about 20cm or 30cm a year," said lead researcher Dr. Mark Meekan from the Australian Institute of Marine Science.
He said the finding also explained why gatherings of whale sharks in tropical regions are made up almost entirely of young males.
"They gather to exploit an abundance of food so they can maintain their fast growth rates," he said.
To conduct the research, the research team visited Western Australia's Ningaloo Reef several times between 2009 and 2019.
Researchers tracked 54 whale sharks by their unique "fingerprints" of spots as they grew and measured their body sizes through time using stereo-video cameras. They also looked into data from whale sharks in aquaria.
Meekan said the discovery has huge implications for the conservation of whale sharks, which were threatened by targeted fishing and ship strikes and listed as endangered in 2016.
"If you're a very slow-growing animal and it takes you 30 years or more to get to maturity, the chances of disaster striking before you get a chance to breed is probably quite high," he said. Enditem