Live fast, die young! From Scientific American - Annual fish 生命無關長短，只求一個精采! 在水塘乾涸之前，我得努力繁衍。

上圖的紅色小魚生長在非洲，這種魚出生後17天即可以繁衍後代，速度之快令人傻眼。不過這樣努力長大產卵，只因為生命非常短促。人類擁有幾十年光陰，切莫蹉跎，還不快點卯起來念英文！

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"Annual Fish" Grow Up at Top Speed

Certain African fish evolved short generations to survive in temporary ponds that dry up after just a few months each year.

Sophie Bushwick reports

In the east African savanna, pools of water form during the rainy season only to dry up a few months later. Being a fish in one of these temporary ponds is a challenge. To survive, they race to maturity成熟, with the shortest generation time每一代都以最短的時間(繁衍成熟) of any vertebrate脊椎動物.

To monitor監控 the development of the so-called annual fish一年生魚類, researchers raised two different species 物種 in the lab.

The fish could grow by almost a quarter of 四分之一 their body length each day. One species could already reproduce at 17 days of age. The other took an additional day. The eggs these youngsters fertilized卵受精 then hatched孵出 in as little as 15 days, leaving only a month between generations每一代的年齡差異，只有一個月的間隔. The study is in the journal EvoDevo.

Embryonic胚胎的 annual fish survive the dry season by lying dormant休眠/靜止 underground. Once the rains return and the pool forms, they quickly reproduce before the water dries up again. Their short generation time is thus a crucial evolutionary adaptation為了適應環境，所出現的重要演化能力. Their temporary ponds短暫的池水 force them to live fast, die young and leave a desiccated corpse乾掉的屍體.

魚類學相關名詞中英對照

名詞 定義 annual fish A fish which normally completes its life cycle in a year and dies, only the eggs surviving, e.g. certain South American and African cyprinodonts dwelling in ponds which disappear in the dry season, Austrofundulus, Rachovia, Aphia pellucida, Cynolebius. 一年生魚類 指某些卵生鱂科魚類的生殖特性，由於居住在河水會完全乾涸的地區，因此壽命皆不足一年，且產卵只有一次。