英语听力文摘 English Digest 165、Can Fish Smell?

　　Y: I noticed that fish have holes that look like nostrils¹, does that mean they can smell?
D: Smell, or olfaction, as scientists call it, is an important sense for many fish. Those little holes that look like nostrils are called nares. Nares don’t lead to the throat the way nostrils do in mammals, but open up into a chamber² lined with sensory³ pads.Not all fish move water in and out through these nares in quite the same ways, but key to a strong sense of smell for fish is the ability to move water rapidly over these sensory pads.Some fish can pick up chemical signals when immobile by pumping water through their olfactory⁴ system via tiny hairs called cilia.Other fish can pump water by a muscular movement. Some fish, such as smaller species of mackerel, have an olfactory system that requires them to swim in order to get water moving through their nares.When the sensory pads pick up chemical signals, they transmit them to the fish’s forebrain, which interprets the signal and incites⁵ the fish to respond appropriately.
Y: You mean like if the chemical signal food, the fish will pursue the food. Or, if the chemical signal danger, they will flee?
D: You got it. But fish use chemical cues in all sorts of ways. For instance, a large group of fishes release a chemical when they’re wounded that incites other fish to flee. And then there are salmon⁶, which are known for a superb sense of smell that enables them to sense the stream where they were born, so that they may return to it to spawn⁷.

1 nostrils   

鼻孔( nostril的名词复数 )

参考例句：

• Her nostrils flared with anger. 她气得两个鼻孔都鼓了起来。
• The horse dilated its nostrils. 马张大鼻孔。

2 chamber   

n.房间，寝室；会议厅；议院；会所

参考例句：

• For many,the dentist's surgery remains a torture chamber.对许多人来说，牙医的治疗室一直是间受刑室。
• The chamber was ablaze with light.会议厅里灯火辉煌。

3 sensory   

adj.知觉的，感觉的，知觉器官的

参考例句：

• Human powers of sensory discrimination are limited.人类感官分辨能力有限。
• The sensory system may undergo long-term adaptation in alien environments.感觉系统对陌生的环境可能经过长时期才能适应。

4 olfactory   

adj.嗅觉的

参考例句：

• He is to develop a sensor to substitute for the olfactory abilities of dogs.克罗克将研制一种传感器用以代替狗的嗅觉功能。
• Based on these findings, Keller suspects that each person has an olfactory blind spot.根据这些发现，凯勒推断，每个人都有一个嗅觉盲区。

5 incites   

刺激，激励，煽动( incite的第三人称单数 )

参考例句：

• In all countries any person who incites others to insurrection is guilty of treason. 在任何国家里，煽动他人谋反者，都属犯叛国罪。
• The success of the handicapped man incites us to pursue our dreams. 这位残疾人的成功激励我们追求自己的梦想。

6 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

7 spawn   

n.卵，产物，后代，结果；vt.产卵，种菌丝于，产生，造成；vi.产卵，大量生产

参考例句：

• The fish were madly pushing their way upstream to spawn.鱼群为产卵而疯狂地向上游挤进。
• These fish will lay spawn in about one month from now.这些鱼大约一个月内会产卵。