[ti:With Whale Sharks, Males Grow Faster, But Females Grow Bigger] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]New research has provided surprising details [00:05.00]about the biology of Earth's largest fish, the whale shark. [00:11.12]Scientists say that female whale sharks [00:15.96]grow more slowly but reach a much larger size than males. [00:22.48]Researchers recently said they had followed the growth [00:26.88]of 54 whale sharks over 10 years. [00:31.84]The creatures swam in the Ningaloo Reef off of Australia's west coast, [00:38.12]where hundreds of the rare fish travel every year. [00:43.40]Whale sharks of both sexes were found to have their fastest growth [00:49.56]while young — about 20 to 30 centimeters per year. [00:56.04]Males were found to grow faster than females. [01:00.48]They reached around eight meters in length at about 30 years old. [01:06.64]At that age, they reach sexual maturity, [01:11.04]meaning the fish were able to produce young. [01:14.64]Females grew larger than males. [01:17.84]Females reached about 14 meters at about age 50, [01:23.92]when they reached sexual maturity. [01:27.36]Mark Meekan is a marine biologist at the Australian Institute of Marine Science. [01:35.84]He led the research that was published in Frontiers in Marine Science. [01:42.48]Meekan described whale sharks as "remarkable." [01:47.24]He noted that females give birth to many young: "up to 300 at one time." [01:55.00]For this reason, Meekan said, female sharks probably need to be very large. [02:03.72]"Our study provides the first evidence that male and female whale sharks [02:09.64]grow at different rates," Meekan said. [02:13.80]Whale sharks are filter feeders, [02:16.84]meaning they take food and nutrients from the water. [02:22.12]They swim great distances to find enough to eat. [02:26.40]The longest-known whale shark ever recorded [02:30.44]reached a length of about 18 meters. [02:34.60]Whale sharks can live for 100 to 150 years. [02:40.56]Meekan suggested the study's findings were important for saving whale sharks. [02:47.72]He noted that if it takes 30 or more years for the creatures to reach sexual maturity, [02:56.00]"there are lots of threats such as hunting [02:59.76]and ship-strike...before they get a chance to breed." [03:04.72]For that reason, Meekan described efforts to save the creatures as "urgent." [03:12.20]I'm John Russell. 更多听力请访问51VOA.COM