The secret lives of baby fish - Amy McDermott

小魚苗冒險王—艾美‧麥克德莫特

譯者: Aaron Shoo 審譯者: Regina Chu

這不是什麼噁心的 X 光片

What you're looking at isn't some weird x-ray.

It's actually a baby yellow tang surgeonfish at two months old.

是隻 2 個月大的 「黃三角倒吊」寶寶

And you thought your childhood was awkward.

牠小時候比你醜多了吧？

But here is the same fish as an adult,

但牠長大後是棲息在 印度洋和太平洋礁區的美麗嬌客

a beautiful inhabitant of the Indian and Pacific Oceans' coral reefs

and one of the most popular captive fish for salt water aquariums.

同時也是海水缸 很受歡迎的魚種之一

Of the 27,000 known fish species, over a quarter live on coral reefs

在 2 萬 7 千種已知的魚種中 有 1/4 住在珊瑚礁海域

that make up less than 1% of the Earth's surface.

而珊瑚礁只佔地球表面不到 1%

But prior to settling down in this diverse tropical environment,

但在多樣的熱帶環境棲身之前

baby coral reef fish face the difficult process of growing up on their own,

珊瑚礁魚寶寶要獨自 面對艱辛的成長過程

undergoing drastic changes, and the journey of a lifetime

在找到稱為「家」的珊瑚礁前

要歷經劇烈的體態變化 和長達將近一生的旅途

before they find that reef to call home.

The life cycle for most of these fish

這類魚的生命大多始於

begins when their parents spew sperm and eggs into the water column.

牠們的父母在水柱中排放精子和卵子

This can happen daily, seasonally, or yearly depending on the species,

依照不同魚種 有的每天、每季，或是每年排放

generally following lunar or seasonal tidal patterns.

基本上是跟著月亮或是季節潮汐週期

Left to their fate, the fertilized eggs drift with the currents,

受精卵隨著命運和洋流開始漂流

and millions of baby larvae hatch into the world.

數百萬的魚苗在漂流中誕生

When they first emerge, the larvae are tiny and vulnerable.

剛出生的魚苗又小又脆弱

Some don't even have gills yet and must absorb oxygen

有的還沒長出鰓 要直接透過薄薄的皮膚吸入氧氣

directly from the water through their tissue-thin skin.

They may float in the water column anywhere from minutes to months,

牠們會順著水流 漂游幾分鐘到幾個月

sometimes drifting thousands of miles across vast oceans,

有時橫越數千英里遠的海洋

far from the reefs where they were born.

遠離出生地

Along the way, they must successfully avoid predators,

旅途中 要成功躲過掠食者、

obtain food, and ride the right currents to find their way to a suitable adult habitat,

找到食物、搭上對的洋流 才能找到適合的居所

which might as well be a needle in vast haystack of ocean.

用「大海撈針」來形容 一點也不為過

So, how did they accomplish this feat?

牠們怎麼達成這個壯舉的呢？

Until recently, marine biologists thought of larval fish as largely passive drifters,

不久之前 海洋生物學家還認為

魚苗是被動地 被洋流帶往合適的棲地

dispersed by ocean currents to distant locales.

But in the last 20 years, new research has suggested

但近 20 年有了新的見解 認為魚苗不如我們想得無助

that larvae may not be as helpless as they seem,

有辦法用牠們的鰭 掌握自己的命運

and are capable of taking their fate in their own fins

to maximize their chances of survival.

創造最大的生存可能

The larvae of many species are unexpectedly strong swimmers,

很多魚的幼苗 是出乎意料的游泳健將

and can move vertically in the water column to place themselves in different water masses

可以垂直在水柱中移動 進入不同的水團

and preferentially ride certain currents.

並且選擇特定的洋流

These fish may be choosing the best routes to their eventual homes.

這些魚會選擇通往棲地 最適合的路線

When searching for these homes,

證據顯示在找棲地時 是藉由一套複雜的知覺系統

evidence suggests that larvae navigate via a complex suite of sensory systems,

detecting both sound and smell.

同時偵測聲音和氣味

Odor, in particular, allows larvae to distinguish between different environments,

特別是氣味 讓幼魚區分不同的環境

even adjacent reefs,

連鄰近的珊瑚礁也能被區分

helping guide them toward their preferred adult habitats.

幫助牠們找到最適合的棲息地

Many will head for far-flung locales miles away from their birth place.

大部分會到離出生地很遠的地方

But some will use smell and other sensory cues

但有些會用氣味或其他線索

to navigate back to the reefs where they were born,

找到自己的出生地

even if they remain in the larval stage for months.

這時可能已經 停留在幼魚階段幾個月了

So, what happens when larvae do find a suitable coral reef?

所以這些小魚找到棲地的下一步呢？

Do they risk it all in one jump from the water column,

牠們會從洋流中冒險一跳

hoping to land in exactly the right spot to settle down

看會不會剛好落在好地方 然後安居樂業、長大成人？

and metamorphose into adults?

Not exactly.

才不會！

Instead, larvae appear to have more of a bungee system.

牠們比較像在玩高空彈跳

Larvae will drop down in the water column to check out a reef below.

牠們會從上層洋流 游下來視察一番

If conditions aren't right, they can jump back up

如果不滿意會再游回去

into higher water masses and ride on,

搭上洋流繼續前進

chancing that the next reef they find will be a better fit.

看下一叢珊瑚礁 會不會比較合適

But this is the point where our knowledge ends.

我們所知就到此為止

We don't know the geographic movements of individual larva for most species.

我們不知道多數魚種的魚苗 可以漂流到哪裡

Nor do we know which exact environmental cues and behaviors they use

也不知道是什麼環境因素 或是牠們的行為

to navigate to the reefs they will call home.

帶牠們找到稱為「家」的地方

But we do know that these tiny trekkers

只知道這些浪跡天涯的小魚

are more than the fragile and helpless creatures

不是科學界一度以為 如此脆弱無助的生物

science once believed them to be.

The secret lives of baby fish remain largely mysterious to us,

小魚苗的冒險 還有許多未知的部分

unknown adventures waiting to be told.

等待我們去發掘