科学家首次测量了世界上比较大的动物——蓝鲸的心率

科学家首次测量了世界上最大的动物——蓝鲸的心率

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.

科学家们在一头蓝鲸身上安装了一台带有吸盘的鲜橙色心电图机，首次测量了这头世界上最大的动物的心率，并对这头著名庞然大物的生理学有了进一步的了解。

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.

研究人员于本周一称，这种身长可达100英尺、体重可达200吨的蓝鲸在潜入海底觅食时，可将心率降至每分钟两下。他们记录的最大心率是在这只呼吸空气的海洋哺乳动物从觅食潜水返回地面后，每分钟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.

“蓝鲸是有史以来最大的动物，一直让生物学家着迷。”斯坦福大学海洋生物学家Jeremy Goldbogen说，他领导的这项研究发表在《美国国家科学院院刊》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?”

“特别是，测量生命率和生理率的新方法帮助我们了解动物在身体质量的上端是如何工作的，”Goldbogen补充说。“生活是什么样的?如此大规模的生活节奏是怎样的?”

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.

一般来说，动物体型越大，心率越低，在向全身输送血液时，心脏的工作量就越小。正常的人类静息心率在每分钟60到100次之间，在运动时最高可达200次。最小的哺乳动物，鼩鼱，心率可达每分钟一千次。

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.

研究人员发明了一种标签装置，它被包裹在一个橙色的塑料壳里，里面装有一台心电图机，用来监测在公海游泳的鲸鱼的心律。该装置有四个吸盘，使他们能够将其无创性地附着在鲸鱼身上。

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

研究人员从一头72英尺长的成年雄性鲸鱼身上获得了9个小时的数据。

“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，我们必须找到蓝鲸，这是非常困难的，因为这些动物在广阔的海洋中活动。通过结合多年的实地经验和一些运气，我们把一个小型的，刚性外壳，充气船在鲸鱼的左侧，”Goldbogen说。

“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，我们必须使用6米(20英尺)长的碳纤维杆来展开标签。当鲸鱼浮出水面呼吸时，我们会在鲸鱼的左鳍后面标记一个我们认为最接近心脏的位置。

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.

须鲸，如蓝鲸，尽管体型巨大，却以微小的猎物为食。作为滤食性动物，它们把大量的水吸入嘴里，用角蛋白制成的鲸须板过滤掉猎物，包括像虾一样的磷虾和其他浮游动物。

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.

在进食时，鲸鱼表现出极低的心率，一般为每分钟4到8次，最低为2次。在觅食潜水后浮出水面呼吸后，鲸鱼的心率为每分钟25到37次。