科學(xué)家首次測量了世界上比較大的動物——藍鯨的心率

科學(xué)家首次測量了世界上最大的動物——藍鯨的心率

Using a bright orange electrocardiogram machine attached with suction cups to the body of a blue whale, scientists for the first time have measured the heart rate of the world’s largest creature and came away with insight about the renowned behemoth’s physiology.

科學(xué)家們在一頭藍鯨身上安裝了一臺帶有吸盤的鮮橙色心電圖機，首次測量了這頭世界上最大的動物的心率，并對這頭著名龐然大物的生理學(xué)有了進一步的了解。

The blue whale, which can reach up to 100 feet long and weigh 200 tons, lowers its heart rate to as little as two beats per minute as it lunges under the ocean surface for food, researchers said on Monday. The maximum heart rate they recorded was 37 beats per minute after the air-breathing marine mammal returned to the surface from a foraging dive.

研究人員于本周一稱，這種身長可達100英尺、體重可達200噸的藍鯨在潛入海底覓食時，可將心率降至每分鐘兩下。他們記錄的最大心率是在這只呼吸空氣的海洋哺乳動物從覓食潛水返回地面后，每分鐘37次。

“The blue whale is the largest animal of all-time and has long fascinated biologists,” said Stanford University marine biologist Jeremy Goldbogen, who led the study published in the journal Proceedings of the National Academy of Sciences.

“藍鯨是有史以來最大的動物，一直讓生物學(xué)家著迷。”斯坦福大學(xué)海洋生物學(xué)家Jeremy Goldbogen說，他領(lǐng)導(dǎo)的這項研究發(fā)表在《美國國家科學(xué)院院刊》上。

“In particular, new measures of vital rates and physiological rates help us understand how animals work at the upper extreme of body mass,” Goldbogen added. “What is life like and what is the pace of life at such a large scale?”

“特別是，測量生命率和生理率的新方法幫助我們了解動物在身體質(zhì)量的上端是如何工作的，”Goldbogen補充說。“生活是什么樣的?如此大規(guī)模的生活節(jié)奏是怎樣的?”

Generally speaking, the larger the animal, the lower the heart rate, minimizing the amount of work the heart does while distributing blood around the body. The normal human resting heart rate ranges from about 60 to 100 beats per minute and tops out at about 200 during athletic exertion. The smallest mammals, shrews, have heart rates upwards of a thousand beats per minute.

一般來說，動物體型越大，心率越低，在向全身輸送血液時，心臟的工作量就越小。正常的人類靜息心率在每分鐘60到100次之間，在運動時最高可達200次。最小的哺乳動物，鼩鼱，心率可達每分鐘一千次。

The researchers created a tag device, encased in an orange plastic shell, that contained an electrocardiogram machine to monitor a whale’s heart rhythm swimming in the open ocean. The device had four suction cups to enable them to attach it to the whale non-invasively.

研究人員發(fā)明了一種標簽裝置，它被包裹在一個橙色的塑料殼里，里面裝有一臺心電圖機，用來監(jiān)測在公海游泳的鯨魚的心律。該裝置有四個吸盤，使他們能夠?qū)⑵錈o創(chuàng)性地附著在鯨魚身上。

The researchers obtained nine hours of data from an adult male whale about 72 feet long encountered in Monterey Bay off California’s coast.

研究人員從一頭72英尺長的成年雄性鯨魚身上獲得了9個小時的數(shù)據(jù)。

“First we have to find a blue whale, which can be very difficult because these animals range across vast swaths of the open ocean. By combining many years of field experience and some luck, we position a small, rigid-hulled, inflatable boat on the whale’s left side,” Goldbogen said.

“首先，我們必須找到藍鯨，這是非常困難的，因為這些動物在廣闊的海洋中活動。通過結(jié)合多年的實地經(jīng)驗和一些運氣，我們把一個小型的，剛性外殼，充氣船在鯨魚的左側(cè)，”Goldbogen說。

“We then have to deploy the tag using a six-meter (20-foot) long carbon-fiber pole. As the whale surfaces to breathe, we tag the whale in a location that we think is closest to the heart: just behind the whale’s left flipper,” Goldbogen added.

“然后，我們必須使用6米(20英尺)長的碳纖維桿來展開標簽。當鯨魚浮出水面呼吸時，我們會在鯨魚的左鰭后面標記一個我們認為最接近心臟的位置。

Baleen whales such as blue whales, despite their immense size, feed on tiny prey. As filter-feeders, they take huge amounts of water into their mouths and strain out prey including shrimp-like krill and other zooplankton using baleen plates made of keratin, the same material found in fingernails.

須鯨，如藍鯨，盡管體型巨大，卻以微小的獵物為食。作為濾食性動物，它們把大量的水吸入嘴里，用角蛋白制成的鯨須板過濾掉獵物，包括像蝦一樣的磷蝦和其他浮游動物。

During feeding dives, the whale exhibited extremely low heart rates, typically of four to eight beats per minute and as low as two. After surfacing to breathe following foraging dives, the whale had heart rates of 25 to 37 beats per minute.

在進食時，鯨魚表現(xiàn)出極低的心率，一般為每分鐘4到8次，最低為2次。在覓食潛水后浮出水面呼吸后，鯨魚的心率為每分鐘25到37次。