of a goldfish” - we’re constantly told that fish are simple and have poor memories.

金魚腦」的俗諺，我們常常聽到魚很笨、魚的記性很差這種說法

But are they more complex than we think?

但他們是不是其實比我們想像的複雜一些呢？

This is the Rotating Snake Illusion - as you move your eyes, the snakes appear to be moving

這是「旋轉蛇」圖樣，當你移動視線，蛇就好像會在圈圈內

in circles, but the image is actually stationary. It turns out that fish see this illusion in

移動，但其實圖片本身是靜止的，結果顯示魚類在觀看這張圖片時

a similar way to you and I. Even though fish diverged from land vertebrates 450 million

有跟我們非常相似的反應，即使他們的演化在4億5千萬年前就跟陸生脊椎動物

years ago, both have developed similar vision to hunt, escape predators, and avoid collisions.

分開了，兩者卻都發展了類似能夠打獵、逃避掠食者、避免撞擊的視力。

Researchers have hypothesized that we see the same motion illusions as a result of ‘convergent

研究者假設，關聯性很低的生物，也有可能因為必須適應相同的環境

evolution’, where organisms not closely related independently evolve similar traits

繼而發展出類似的特質

as a result of having to adapt to similar environments.

這就是「趨同演化」的結果

Which of these red circles is larger? Your eyes are likely telling you the one on the

哪個紅圈圈比較大？你的眼睛可能會告訴你說是

right, and a fish would think so too. But it turns out they are the same size. In a

右邊那個，魚類也會這樣想，但結果其實它們是一樣大的

study on redtail split fins, the fish were trained to discriminate between disks of different

在某項關於艾氏異仔鱂的研究當中，這種魚被訓練成能夠分辨不同大小的光碟

sizes and to prefer larger disks. And when presented with a similar illusion they chose

並且會選擇比較大的那個，當牠們被呈現在類似的圖樣前面時，牠們也會選擇

the deceptively larger one.

看起來好像比較大的那一個。

What about attention span? One particular report found that the human attention span

至於「注意廣度」呢？有一樣特別的研究發現，人類的注意廣度

is down from 12 seconds in the year 2000, to 8 seconds today. Our use of the internet

從2000年的12秒，下降至現在的8秒，理論推測這是我們對於網路

and devices is theorized to play a role but, either way, goldfish have a 9 second attention

與各種載具的使用所導致的，但無論如何，金魚有9秒鐘的「注意廣度」

span, trumping that of a human.

大勝人類！

When it comes to forgetfulness, a study using African Cichlids gave fish a food reward in

談到「健忘度」，一項對於非洲慈鯛做的研究，他們在水族箱裡面設定了

a particular zone of an aquarium for 3 days in a row. Then, the fish were given a 12 day

一個特定的區域，讓這些魚連續3天可以在那裡得到獎賞，然後，牠們要休息12天，

‘rest’ period before being reintroduced into the aquarium. Using motion-tracking software,

直到下一次再被帶進同樣的水族箱。利用情緒追蹤系統，

the cichlids showed a distinct preference to the area of the aquarium where they had

慈鯛對於那塊他們先前得到獎賞的水族箱區域會有

previously received a reward. Studies have even shown goldfish can remember things for

明顯的偏愛。研究甚至表示，金魚可以保持記憶至少3個月，

at least 3 months; distinguishing between shapes, colours, sounds, and even navigating

不論分辨形狀、顏色、聲音甚至是在迷宮中的導航

mazes. On top of this, goldfish can recognize their owners. Ultimately, fish have been shown

除此之外，金魚可以認得出他們的主人，最後，研究顯示魚類

to have quite good memories - after all they need to remember prey types, avoid predators

其實擁有相當不錯的記憶力，畢竟牠們需要記住獵物長什麼樣子、躲開掠食者

and even avoid our hooks after being caught in the past.

甚至要在被抓到之後記得從此不再靠近我們的魚鉤

But when it comes to pain we’re actually quite different than fish. When you injure

不過當講到「疼痛」時，我們其實跟魚類滿不一樣的。當你弄傷自己，

yourself, receptors in your body called ‘nociceptors’ send signals to the neocortex where the sensation

你體內的感覺器官，稱之「痛覺受器」，會把訊號傳達到「新皮質」，也就是痛覺會被

of pain is processed. But many fish lack nociceptors and all fish lack a neocortex, so pain isn’t

處理的地方，但很多魚類都缺乏「痛覺受器」，而所有魚類都沒有「新皮質」，所以疼痛

experienced in the same way.

感覺起來是不一樣的。

When Finding Nemo was first released, hundreds of fish were flushed to set them ‘free’,

當「海底總動員1」第一次上映時，成千上萬的魚都被沖進馬桶「放生」，

while in reality these fish often die from trauma or exposure to fresh water. Additionally,

但在現實情境中，牠們會因為嚴重受傷或暴露於淡水中而死去，此外，

researchers worry that Finding Dory’s release could increase the decline in ornamental fish

研究者也擔心「海底總動員2」會造成觀賞魚數量下滑

populations as more people will want the Royal Blue Tang as a pet.

因為人們會想擁有一隻藍刀鯛做寵物。

So we decided to make a video on 8 other Amazing Aquatic Animals on AsapTHOUGHT, where we visited

所以我們打算在AsapTHOUGHT頻道做一支影片介紹其他8種奇妙的水生動物

an aquarium to check them out in person. Our lakes and oceans are full of some wild and

是我們親自到水族館去拜訪過的，我們的湖泊與海洋充滿各式各樣野生又

beautiful creatures, so be sure to check it out with the link below!

美麗的生物，一定要點擊下面的連結去看看！

And Subscribe for more weekly science videos!

記得訂閱我們，看更多的科學影片哦