英汉双语阅读92：海豚与鼠海豚——海洋 “撞脸” 难题

摘要：Dolphins and porpoises are some of the most charismatic critters in the ocean - but can you tell them apart? Although they might l

高效记单词：《新概念英语1词汇专练》

英汉双语阅读91：兔子粘液瘤病侵袭澳大利亚：“后天” 灾难上演

一、生词准备

charismatic [ˌkærɪzˈmætɪk]：adj. 有魅力的；有吸引力的

cetacean [sɪˈteɪʃn]：n. 鲸目动物；adj. 鲸类的，鲸目的

echolocation [ˌekoʊloʊˈkeɪʃn]：n. 回声定位

prey [preɪ]：n. 猎物；被捕食的动物

bulbous [ˈbʌlbəs]：adj. 球根状的；球状的

pronounced [prəˈnaʊnst]：adj. 明显的；显著的

dorsal [ˈdɔːsl]：adj. 背部的；背的

triangular [traɪˈæŋɡjələr]：adj. 三角形的

streamlined [ˈstriːmlaɪnd]：adj. 流线型的

vaquita [vɑːˈkiːtə]：n. 小头鼠海豚

cone-shaped [ˈkoʊn ʃeɪpt]：adj. 圆锥形的

spade - shaped [ˈspeɪd ʃeɪpt]：adj. 铲形的；锹形的

hooked [hʊkt]：adj. 钩状的，弯曲如钩的

二、短文内容

Dolphins and porpoises are some of the most charismatic critters in the ocean - but can you tell them apart? Although they might look alike at first glance, there are a few key differences that make it easy to tell which is which.

Let’s start with what they have in common: both dolphins and porpoises are cetaceans, an order of marine mammal that also includes whales. They’re further classified as toothed whales along with belugas, narwhals and sperm whales. While they’re both highly intelligent, dolphins are typically more curious around humans than porpoises are. Both animals use echolocation, which uses sound to sense what is around them, to hunt for prey and find their peers.

To tell these two cetaceans apart, first look at the head. Dolphins typically have a bulbous head and often a clearly-defined “beak,” or long nose that sticks out from their face. Porpoises, on the other hand, usually have a rounder face without the pronounced beak. If you can’t get a good look at the head, take a peek at the fin. Dolphins have curved dorsal fins, while porpoises have dorsal fins that are more triangular in shape. This is one of the quickest ways to tell them apart, especially if you spot one while out on the water and can’t get a look at the whole animal.

If you are able to see the entire animal, you can tell the two apart by their size and shape. Dolphins tend to have a sleeker, more streamlined body shape than porpoises. Dolphins are also often longer, averaging about six to 12 feet in length, while porpoises only reach a maximum seven feet in length. The smallest toothed whale is the vaquita, an extremely endangered species that only grows to about four feet and 120 pounds.

If you get a really good look, examine its teeth. Dolphins’ teeth are cone-shaped, while porpoises’ teeth are spade-shaped. Although, let’s be honest - if you’re close enough to see the specific shape of their teeth, you’re probably a little too close. If you’re still unsure about the difference between the two, the odds could be in your favor - there are 33 species of dolphin and only six species of porpoise.

In short, if you come across a sleek, large cetacean with a defined beak and a hooked dorsal fin, you’re likely looking at a dolphin. On the other hand, if you’re looking at a smaller, chunky animal with a round face and triangular dorsal fin, you’ve probably found a porpoise.