You're swimming in the ocean when something brushes your leg.

在海中游泳的時候有個東西掃過你的腿

進階被動語態

you realize you've been stung  by a jellyfish.

How do these beautiful, gelatinous creatures pack such a painful punch?

如此美麗的凝膠狀生物怎麼會有這種攻擊能力呢?

Jellyfish are soft  because they are 95% water

水母很柔軟，因為他們含有95%的水

and are mostly made of a translucent gel-like substance called mesoglea.

而且主要由一種半透明的凝膠狀物質組成，稱為"中膠層

they rely on thousands of venom-containing stinging cells called cnidocytes

他們需依賴成千個有毒的有刺細胞，稱為"刺胞"

Even baby jellyfish,  the size of a pencil eraser,

即使是只有鉛筆尾端橡皮擦那麼小的水母寶寶，

Larval jellyfish, ephyrae, look like tiny flowers pulsating in the sea.

水母的幼蟲，幼體，看起來像一朵朵小花在海中脈動

As they grow, they become umbrella-shaped with a bell at the top

當他們長大後會變成傘狀，頭上是一口鐘的造型，

and descending tentacles around the margin.

The largest species of jellyfish, the lion's mane,

has tentacles that can extend  more than 100 feet,

These tentacles contain most of the stinging cells,

although some species have them on their bells, too.

但有些種類的水母連頭上也有刺胞

which lies coiled under high osmotic pressure.

When mechanical or chemical stimuli activate an external mechanical

當受到物理或化學性刺激時，觸發外部的機制系統

the lid of the cell pops open and sea water rushes in.

This forces a microscopic barbed harpoon to shoot out,

這股力量促使一個極微小的魚叉發射

penetrate and inject venom into its victim.

Nematocyst discharge can occur in less than a millionth of a second,

刺絲囊釋出毒液的時間少於百萬分之一秒

making it one of nature's fastest biomechanical processes.

這是自然界中最快速的生物力學作用之一

Nematocysts can continue to fire even after a jellyfish has died,

即使水母已經死掉了，刺絲囊仍能持續地攻擊

so it's important to remove lingering tentacles stuck to the skin.

所以把附著在皮膚上的纏人觸手除掉很重要

Rinsing with vinegar will usually render undischarged nematocysts inactive.

用醋沖洗通常能制止刺絲囊繼續釋放毒液

Seawater can also help  remove residual nematocysts.

海水也能幫助去除殘餘的刺絲囊

But don't use fresh water because any change in salt balance

但不要用清水沖，因為任何鹽度平衡的變化，

alters the osmotic pressure outside of the cnidocyte

That's why urinating on the affected area, a common folk remedy,

這也是為什麼尿尿在被螫的地方，這種民俗療法

may do more harm than good, depending on the composition of the urine.

可能因尿液成分的不同，而造成更多傷害

Most jellyfish stings are a painful nuisance,

大部分的水母螫只是又痛又討人厭而已

An Indo-Pacific box jelly, also called a sea wasp,

一種印度洋-太平洋海域的箱形水母，又稱海黃蜂

releases venom which can cause contraction of the heart muscles

There's an anti-venom, but the venom is fast-acting,

雖然有解毒劑，但毒液作用非常快

so you'd need immediate medical intervention.

Despite the impressive power in their tentacles,

Their stinging cells are no match for the armor of thick-skin predators,

他們的刺胞對全副武裝的獵食者一點用也沒有

like the leatherback turtle and ocean sunfish.

These predators both have adaptations that

prevents slippery jellyfish from escaping after they are engulfed:

避免滑溜溜的水母在被吞掉的時候逃走

backwards pointing spines in the turtle's mouth and esophagus

海龜的嘴巴和食道裡有向後長的尖刺

and recurved teeth  behind the sunfish's cheeks.

翻車魚的臉頰裡有向後鉤的牙齒

Even tiny lobster slipper larvae can cling to the bell of a jellyfish

甚至有小小的蟬蝦幼蟲會附著在水母頭裡

snacking on the jelly while they preserve their own energy for growth.

吸收水母的營養，儲存能量用來成長

Small agile fish use the jellies as moving reefs for protection,

敏捷的小型魚類把水母視為移動珊瑚礁，作為掩護

darting between tentacles without ever touching them.

Nudibranchs, which are sea slugs covered in protective slime,

裸鰓亞目動物，也就是海蛞蝓，身上有一層保護黏液

can actually steal the jelly's defenses by eating the cnidocytes

他們可以偷走水母的防衛機制，他們吃掉刺胞

and transferring them to specialized sacks for later use,

並將它們傳送到特化的囊袋裡，留待之後使用

Even humans might benefit from the sting of a jellyfish one day.

甚至有一天，人類也能從水母螫刺上得到好處

Scientists are working on manipulating cnidocytes to deliver medicine,

科學家正在研究如何控制刺胞來傳遞藥物

with nematocysts rarely 3% of the size of a typical syringe needle.

因為刺絲囊幾乎只有傳統注射器針頭3%大小

So, the next time you're out in the ocean, be careful.

所以，下次到海邊玩水的時候小心一點

But also, take a second to marvel at its wonders.

但也別忘了花點時間，讚嘆水母的奧妙

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