5 Incredible Fish Behaviors That Show Just How Intelligent They Really Are

The vast majority of people are under the illusion that fish are unintelligent and incapable of feeling pain in the same way as mammals, a thought process which leads to a care free attitude towards the capture and murder of billions of fish each year for food.

An incredible study of fish behavior by a team of marine biologists led by Redouan Bshary proves once and for all just how clever fish really are. Here are five complex behaviors which he observed and documented:

Mutual Co-operation

There are numerous instances of mutual co-operation in the animal kingdom, and the great barrier reef is a hive of activity, involving thousands of different marine species, many of whom have learnt to co-operate with each other for mutual benefit.

The most impressive of these systems is the ‘cleaning stations’ where larger fish will come and let the smaller ‘cleaner fish’ eat the tiny parasites off of them. This means food for the cleaner fish and less parasites for the larger ones.

Cheating the System

The complexity of the activities observed at the cleaning stations was astonishing, and Bshary watched the cleaner fish alter their behavior depending on how busy the cleaning station was and how many other cleaner fish were around to service their ‘clients.’

The cleaner fish prefer the taste of the nutritious protective mucus which covers the skin, and they will take the occasional bite. When the larger fish are bitten they thrash around, but would usually put up with the occasional bite or two. However, if there are lots of other cleaner fish to choose from, they will go elsewhere for a cleaning.

The cleaner fish have learned that they can cheat the system and take more bites of the mucus depending on how many other potential clients or cleaning fish were around, as they can get away with it if there is nobody else to clean them.

Hunting Partners

Numerous hunting partnerships have been observed between some of the top predators on the reef, groupers and morays. Normally these fish would be expected to be in competition together, but have worked out a hunting system which is mutually beneficial.

One of the fish swims into the reef and flushes out their prey into the open water, or an enclosed channel, where they become an easy target for all to eat.

Body Language Signalling

The hunting fish use sophisticated body language communications to synchronize their attacks, with a nod of the head being the final cue to action.

This kind of complex communication is not specific to fish found on the coral reef, and is observed in fish populations around the world, the most visually impressive of which is the synchronized schooling of thousands of tuna, who swirl around to confuse predators.

Identifying Fast Food Options

One of the most impressive observations made by Redouan Bshary was that cleaner fish had cognitive processing skills greater than those observed by primates, and even his 4-year-old daughter.

A food plate test was set up to see if the fish would learn to recognize that one plate of food would always remain in place, and another would only stay for a short amount of time before disappearing, and that they needed to eat from this plate first.

The cleaner fish excelled, and showed their superior perception by very quickly learning to eat from the plate which would soon disappear, before eating from the stationary one. They even worked this out under a number of more in depth tests, such as with different colored plates.

In contrast, the primates who had previously tried this test took much longer to learn how to adapt to the system, and Bshary’s 4-year-old daughter never once worked it out, after more than 100 attempts.

Perceiving the World through New Eyes

As humans, we have developed a very self centric view of the world, where we judge all other species by our own perception of them. For us to develop into a more compassionate society, which is not responsible for the murder of billions of animals each year, we must learn to understand and respect each and every animal on the planet for who they are.

Photo Credit: Nathan Rupert


Marija M
Marija Mabout a month ago


Mark Donner
Mark Donnerabout a year ago

By the way for those humans who use the excuse of plants to inflict terror on animals, yes plants react on a cellular level for survival, all cell based organisms do that. But if you noticed before dropping out of third grade, plants don't have nervous systems to feel pain and brains to experience evolved emotions and intelligence like animals do. Sorry, it's not an excuse.

Mark Donner
Mark Donnerabout a year ago

Two false assumptions:
1) Humans are intelligent, moral and experience emotions.
2) What fish do is only instinct, therefore they have no emotions, no intelligence, and no moral choices.

In fact it's the exact opposite, if you replace the word "humans" with "fish" in 1) and replace the word "fish" with "humans" in 2) you have the correct statement

Mark Donners
Mark Donnerabout a year ago

I have stopped eating fish. Only shrimp, but I don't know if that is acceptable either.

Joseph Glackin
Joseph Glackin1 years ago

Thank you!

Siyus Copetallus
Siyus Copetallus1 years ago

Thank you!

Roberto Meritoni
Roberto Meritoni2 years ago

Thanks for sharing

Laurie H.
Laurie H2 years ago

I have no doubts at all that fish have intelligence & have the capacity to suffer and experience pain. Perhaps one day, all life will be respected and appreciated as I believe it was meant to be.~

Giovanna M.
Giovanna M2 years ago

did give proof of learning and making the most of a situation by fish. It is sad that new "science" is so poor compared to older one.

Giovanna M.
Giovanna M2 years ago

I wish scientists would go back to being mainly interested in writing for their peers than for regular media. Maybe then, the quality of investigations would go up again, and when people use supposedly scientific references they would actually quote something that really is worth mentioning.

This story´s author, Ms Geer, claims as source and gives a link to "And incredible study of fish behavior". Despite it appears in Nature, what she thinks is a study is not a study at all, but just a feature article on Bshary. That Nature is wasting space on social pieces already shows how low scientific publishing has gone. That Geer thinks this is actually a scientific study shows how dangerous this new tendency is, for people believe this is science (or use what used to be reputable scientific sources as Nature to justify their points).
Bshary studies fish behavior. In traditional ethology, most of the behaviors cited are not a proof of intelligence but imprints and evolution results. It would be like saying some plants are intelligent because they get animals to swallow their seeds in order to spread them around through feces. Things may have changed since I did my PHD, but symbiosis was not necessarily considered intelligent behavior, else lichens would be considered extremely intelligent.
That does not mean fish are not intelligent. They are, and they have good memory too. Konrad Lorenz 100 years ago proved that with very simple and elegant experiments that did give proof