According to foreign media CNET reports, whale sharks are large, usually 8 or 9 meters long. But in the last decade, the “gender war” still exists: which is bigger, male or female? Female sharks, the largest fish in the sea, outnumber males by body length by an average of 14 meters, according to a new study published Wednesday in the journal frontiers of marine science. Mark meekan, a fish biologist at the Australian Institute of Marine Sciences and the first author of the paper, points out that some whale sharks are even 18 meters long. “It’s absolutely huge – about the size of a big bus on a city street,” he said. “But even if they’re big, they’re growing very, very slowly. It’s only about 20 or 30 centimeters a year. ” < / P > < p > due to the slow growth rate, the team tracked 54 whale shark individuals over a 10-year period, recording more than 1000 measurements with stereo video cameras. “It’s basically two cameras set on a frame, and when you’re underwater, you push along the frame,” said Brett Taylor, a biologist at the Australian Institute of Marine Sciences and co-author of the study. < / P > < p > “it works the same way as our eyes – so you can calibrate two video recordings and make very accurate measurements of sharks,” Taylor said. < / P > < p > the team also found that larger female whale sharks may be beneficial in producing offspring. Researchers have found 300 juveniles and egg shells in a female whale shark, which is different from 2 to 12 juveniles produced by most sharks. The discovery of < / P > < p > may also have an impact on protection. Whale shark has been listed as an endangered species since 2016. Given their slow growth rate, whale sharks being targeted by fishermen could lead to a further decline in the number of these animals. < / P > < p > “if it’s a very slow-growing animal that takes 30 years or more to reach adulthood, then the risk of disaster can be quite high before there is a chance to reproduce,” meekan said. “For whale sharks, it’s really a concern.” Global Tech

By ibmwl