Have you ever seen a great white shark get air as it chases a seal? How about watching salmon climb a salmon ladder as they try to reach their breeding grounds? Well, then it must make you think that fish are pretty athletic right? A study put out by researchers with the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Australia have not only confirmed the notion that fish are fairly athletic, they have shown that fish are the most athletic animals on the planet thanks to their capability to more effectively deliver oxygen throughout their body than any other animal.
“Fish exploit a mechanism that is up to 50-times more effective in releasing oxygen to their tissues than that found in humans,” said Dr. Jodie Rummer, lead author of the study.
“This is because their haemoglobin, the protein in blood that transports oxygen, is more sensitive to changes in pH than ours and more than the haemoglobins in other animals.”
Rummer and her colleagues found that during times of stress, such as escaping predators, or when the oxygen content is low in the water in which they are living, fish can double and triple the rate of oxygen delivery to their tissues to better help their bodies cope. The researchers examined the oxygen delivery mechanisms in the rainbow trout, a common game and food fish, monitoring muscle oxygen levels in real time and found their rate of oxygen increased according to stress levels.
“This information tells us how fish have adapted this very important process of getting oxygen and delivering it to where it needs to be so that they can live in all kinds of conditions, warm or cold water, and water with high or low oxygen levels,” said Dr. Rummer.
“This trait may be particularly central to performance in athletic species, such as long distance swimming salmon or fast swimming tuna,” said co-author, Dr. Colin Brauner from the University of British Columbia.
“For fish, enhanced oxygen delivery may be one of the most important adaptations of their 400 million year evolutionary history,” Dr. Brauner said.