The Titans of the Oceans(a)|海洋里的巨人

by Owain Mckimm

The population of blue whales has gone way down over the past century.

The word big doesn't do blue whales justice. Widely believed to be the largest animals that have ever existed, these majestic giants of the deep boast statistics that put even the dinosaurs to shame. A typical blue whale weighs in at around 200 tons, which is almost twice as heavy as the largest known dinosaur. In addition to its incredible weight, the blue whale can grow to be over 30 meters long, which is longer than an NBA basketball court. Its arteries, more like tunnels than blood vessels, are wide enough for a person to crawl through.

To fuel such a gigantic body, the blue whale has an appetite of epic proportions. The blue whale's diet consists mainly of krill, tiny shrimp-like crustaceans. To get enough nutrition and energy from such tiny creatures, the blue whale consumes some 40 million of them a day, resulting in a daily intake of 1.5 million kilocalories. Blue whales suck in thousands of krill with each massive intake of water. They then push the water out through hundreds of long plates at the front of their mouths. These plates are coated with thick bristles, which allow the water to escape, but retain the krill and other small fish.

Blue whales are found in every ocean in the world. Unlike other whale species, the blue whale is rarely seen in groups of more than two. They are solitary creatures, preferring to wander the oceans alone. However, this doesn't mean that they never congregate. In areas where there is abundant food, up to 50 whales may gather to enjoy the feast. During winter, blue whales move towards the equator together to breed and give birth in the warmer waters.

海洋里的巨人

蓝鲸的总数在过去一世纪以来已经一路下降。

用『巨大』这个词来描述蓝鲸对牠们并不公道。人们普遍认为蓝鲸是有史以来曾经存在的动物中体型最大的，这些深海中的雄伟巨兽拥有连恐龙都蒙羞的统计数字。一头典型的蓝鲸体重约 200 吨重，如此的重量几乎是已知最大型恐龙的两倍。除了令人难以置信的重量之外，蓝鲸可以长到三十多公尺，比一座美国职篮球场还要长。蓝鲸的动脉不像血管，反而更像是隧道，当中的宽度足够一个人爬行通过。

为了推动如此庞大的身躯，蓝鲸的胃口无比巨大。蓝鲸的食物主要由磷虾组成，这是一种外型类似虾子的甲壳类动物。为了要从这么小的生物中获取足够的养分和能量，蓝鲸每天要吃下约 4 千万只的磷虾，如此使得蓝鲸每天可以摄取 150万大卡的热量。蓝鲸每次大量饮水时都会吸入数千只磷虾。牠们接着把水从位于嘴巴前方的上百片鲸须板之间排出。这些鲸须板上都覆盖着厚厚的鲸须毛，让水能够流出嘴外，却留住磷虾和其他的小型鱼类。

世界上每一座海洋中都找得到蓝鲸的踪影。不同于其他种类的鲸鱼，你很少看见两只以上的蓝鲸同时出现。蓝鲸是独居生物，牠们比较喜欢独自漫游在大海中，然而，这不代表蓝鲸从来不会群聚。在一些食物充足的地方，可能就会有多达 50 只的蓝鲸聚集在一起享受美食飨宴。冬季时，蓝鲸会一起游向赤道，以便进行繁殖，并在温暖的水域生下小宝宝。