LOS ANGELES, Nov. 25 (Xinhua) -- Researchers at Stanford University reported the first-ever recording of heart rate of a blue whale, according to a new study published on Monday.
Researchers used a collection of electronic sensors bobbed along the surface of the Monterey Bay, California, encased in a neon orange plastic shell, to record the data.
The device was fresh off a daylong ride on a blue whale. Four suction cups secured the sensor-packed tag near the whale's left flipper, where it recorded the animal's heart rate through electrodes embedded in the center of two of the suction feet.
The details of the tag's journey and the heart rate it delivered were published Monday in Proceedings of the National Academy of Sciences.
"We had no idea that this would work and we were skeptical even when we saw the initial data. With a very keen eye, Paul Ponganis, our collaborator from the Scripps Institution of Oceanography, found the first heart beats in the data," said Jeremy Goldbogen, assistant professor of biology in the School of Humanities Sciences at Stanford and lead author of the paper.
Analysis of the data suggests that a blue whale's heart is working at its limit, which may explain why blue whales have never evolved to be bigger, according to the study.
The data also suggests that some unusual features of the whale's heart might help it perform at these extremes.
"Animals that are operating at physiological extremes can help us understand biological limits to size," said Goldbogen. "They may also be particularly susceptible to changes in their environment that could affect their food supply. Therefore, these studies may have important implications for the conservation and management of endangered species like blue whales."