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

But are they more complex than we think?

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

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

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

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

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

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

as a result of having to adapt to similar environments.

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

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

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

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

the deceptively larger one.

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

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

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

span, trumping that of a human.

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

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

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

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

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

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

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

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

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

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

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

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

experienced in the same way.

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

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

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

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

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

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

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

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