VOA慢速英语2019 科学家获得了蓝鲸心率的首次测量数据（在线收听）

Scientists Get First-Ever Measure of Blue Whale Heart Rate

For the first time ever, scientists have recorded the heart rate of the world's largest creature: the blue whale. To get this reading, they attached an electrocardiogram device to the body of a whale.

科学家们有史以来第一次记录了世界上最大生物蓝鲸的心率。为了获得此读数，他们将心电图仪连接到了鲸鱼的身体。

They found that the mammal's heart rate can slow to just two beats a minute as the animal searches for food below the surface of the ocean. The highest heart rate they recorded was 37 beats a minute after the whale returned to the surface for air.

他们发现，随着哺乳动物在海洋表层以下寻找食物，哺乳动物的心率每分钟可能会减慢至两拍。他们记录到的最高心率是鲸返回地面后每分钟37次。

The team's study appears online in the publication Proceedings of the National Academy of Sciences.

该小组的研究在线发表在《美国国家科学院院刊》上。

The blue whale is the largest animal that has ever lived. It can grow to 30 meters long and weigh as much as 181,000 kilograms. The animal's heart alone weighs more than a fully grown cow.

蓝鲸是有史以来最大的动物。它可以长到30米，重达181,000公斤。仅动物的心脏就比完全成长的母牛重。

Stanford University ocean biologist Jeremy Goldbogen led the blue whale heart rate study. He said such research helps scientists understand how massive animals operate.

斯坦福大学海洋生物学家杰里米·戈德博根（Jeremy Goldbogen）领导了蓝鲸心率研究。他说，此类研究有助于科学家了解大型动物的运作方式。

Generally, larger animals have slower heart rates. A normal human heart of a person at rest beats 60 to 100 times each minute. It increases to about 200 beats a minute during exercise. The smallest mammals, shrews, have heart rates of more than a thousand beats per minute.

通常，大型动物的心律较慢。正常人的静止心脏每分钟跳动60至100次。在运动过程中，它可以增加到每分钟200拍左右。最小的哺乳动物，每分钟心律超过一千次。

The researchers recorded nine hours of information on a 22-meter-long male from the Pacific Ocean off the coast of California. The data did not come easily.

研究人员记录了来自加利福尼亚海岸太平洋上一头22米长的雄性的9个小时的信息。数据来之不易。

"First, we has to find a blue whale, which can be very difficult" Goldbogen said, because these animals live across massive areas of open ocean. But, with years of research experience and some luck, he explained, the team was able to position a small boat along the whale's left side.

Goldbogen说：“首先，我们必须找到一条蓝鲸，这可能非常困难。”因为这些动物生活在广阔的大洋地区。但是，他解释说，凭借多年的研究经验和一定的运气，该团队得以沿着鲸鱼的左侧放置一艘小船。

Then, the researchers connected a special recording device to a very long pole. As the whale surfaced to breathe, they quickly deployed the device as near to the animal's heart as possible: just behind its left flipper. The small device had four suction cups on it, permitting it to remain on the whale for several hours.

然后，研究人员将一个特殊的录音设备连接到一个很长的杆上。当鲸鱼浮出水面呼吸时，他们迅速将设备部署在尽可能靠近动物心脏的位置：在其左脚蹼的后面。小型装置上有四个吸盘，可以将其在鲸鱼上停留数小时。

Blue whales belong to the baleen whale family. These whales are toothless. Instead of teeth, they have baleen, a softer material made from the same substance as fingernails.

蓝鲸属于须鲸家族。这些鲸鱼无牙。他们取而代之的是Baleen，这是一种柔软的材料，由与指甲相同的物质制成。

To feed, the whales flood their mouths with huge amounts of water and then release it through the baleen. It serves as a filter, trapping krill and other very small sea animals that make up the baleen whale diet.

为了喂养，鲸鱼用大量的水淹没了他们的嘴，然后通过baleen将其释放。它可以作为过滤器，捕捞磷虾和其他非常小的海洋动物，它们构成了鲸鱼的饮食。

During feeding dives, the blue whale under observation showed extremely low heart rates, usually of four to eight beats a minute and as low as two beats a minute. After surfacing to breathe after food dives, the whale had heart rates of 25 to 37 beats per minute.

在喂食潜水期间，观察到的蓝鲸显示出极低的心律，通常每分钟四到八次，而每分钟低至两下。潜水之后，鲸鱼浮出水面呼吸，心跳每分钟25到37次。

Blue whales have fascinated biologists and people in general for years. They are not only the largest and biggest-brained animals. They are also the loudest. They can communicate with other whales hundreds of miles away.

蓝鲸多年来一直令生物学家和人们着迷。它们不仅是最大和最聪明的动物。它们也是最大声的。他们可以与数百英里外的其他鲸鱼进行交流。

Words in This Story

electrocardiogram – n. a machine that detects and records the electrical activity of the heart

mammal – n. a type of animal that feeds milk to its young and that usually has hair or fur covering most of its skin

diet – n. the food that a person or animal usually eats

flipper – n. one of two flat body parts that stick out from the side of a seal, whale, etc., and are used by the animal for swimming

fascinate – v. to cause (someone) to be very interested in something or someone