Whale Shark ultrasounds reveal new insights into the world’s largest fish

Ultrasound technology usually used on livestock has offered researchers a new method to give whale sharks in the State’s North West a health check. The method was identified during expeditions to the Ningaloo Reef, when researchers from Japan, the United States and Australia first used the hand-held units while freediving to survey the internal organs of a dozen of the animals. The University of WA’s Oceans Institute Adjunct Senior Research fellow Dr Mark Meekan said the scans were made possible as experts collected tiny parasites from the whale sharks’ lips and fins. “We found when we started to scrape the (parasites) off their lips, the whale sharks slowed down, hung vertically in the water and treated us like a giant cleaner fish,” Dr Meekan said. Dr Meekan — who has been studying the animals for two decades as part of a monitoring program with the Australian Institute of Marine Science — said researchers were also able to learn more about the whale shark’s skin surface during the dives. “We also imaged the back of the shark and could clearly see the skin thickness and muscle bundles,” he said. “They have a layer of hard denticles at the skin surface that feels rough like sandpaper and below that connective tissue up to 20cm deep, making their skin one of the thickest of any animal. “We found whale sharks that were skinny and in poor condition had thinner skins.” Other findings which were also published as part of the new research showed the heart rates of whale sharks were between 12 to 16 beats per minute.