A narwhal catches a breath at the surface between forays to the bottom in search of food. In medieval Europe, tusks were sold as the horns of unicorns.

• 一直独角鲸在准备潜水寻食之前浮出水面透气。在中世纪的欧洲，它们的角被当作传说中的独角兽的角来卖。