Trying to understand fish behavior can be difficult. Some of them can be solitary creatures, others like to mingle together, whereas some will swim in shoals. It makes you wonder whether or not fish can be friends with each other.
The answer can be a little complicated, especially considering that fish don’t have the same cognitive abilities we do. Let’s tackle this question and how it impacts keeping fish in an aquarium.
Can Fish Be Friends with Each Other?
Without wishing to get too deep, this depends on your definition of friendship! The reality is that fish cannot form close relationships in the way that us humans can. However, they can interact with each other in a friendly way and communicate with each other.
Fish will display a wide range of social behaviors that can vary greatly from one species to the next. These behaviors are mostly driven by either survival, territorial, or reproduction instincts. But it does mean that fish, even from different species, can happily co-exist with each other.
Examining Fish Social Behaviors
Perhaps the most famous fish social behavior is shoaling, or schooling. These are both terms used for the synchronized swimming of large groups of fish. This is done to provide safest numbers and improve foraging efficiency. While done for survival, the communication and coordination required does show a basic understanding of social bonding.
Other fish will form long-term pair bonds. Clownfish (yes, nemo fish!) are a good example of this. The male and female will work together to protect their anemone and raise their offspring. Just like a marriage, these partnerships involve cooperation and shared responsibilities.
There are also mutual relationships. Cleaner wrasses will remove parasites and dead skin from larger species. The fact the larger fish doesn’t eat the cleaner wrasse, and even seeks out its services, shows a level of trust and cooperation.
Finally, there are also fish which can have a social hierarchy, such as what you can observe with gorillas and other animals. Cichlids are the best example of this as there will usually be a dominant male with every fish below them being a subordinate.
Proof of Fish Bonding
Fish bonding hasn’t just been theorized but has been observed and tested many times. It has been shown that fish can recognize and remember members of the same species. Some species can tell the difference between fish they have or haven’t seen before, and would prefer to associate with the fish they recognize.
When familiar groups have been placed together, there will also be a reduction in aggression. Fish are driven by instincts and are naturally wary of anything new. A familiar companion will give them a sense of comfort and reduce potential conflicts. Fish can even learn to recognize their owners and the routines that go with it.
There is also cooperative hunting, where fish work together to corner prey and use their strengths to get the kill. Groupers and moray eels do this and show not only cooperation but also trust that they’ll all get a fair share of the prey.
Can Fish Experience Emotions?
Fish are sentient beings which can experience a range of basic emotions. Their brains may not be nearly as developed as ours, but they have the capacity to understand their actions. For example, they avoid being eaten not just because of instincts but also through fear and anxiety.
Fish have dopamine, serotonin, and oxytocin-like systems which help to control feelings of reward and stress. Not only do they have these emotions, but fish usually have good memories. This is even true for goldfish, despite the popular myth.
This memory helps with bonding. Fish will get an increase of stress when separated from a familiar companion. And with familiar companions, they will help more content and are less likely to get stressed.
In fact, stress is an important consideration for aquarium owners. Fish can get stressed and become unhappy for a wide range of reasons, and it will have a negative impact on their health. Their immune system will weaken, making them more likely to get ill. It shows that fish are much more than just mindless creatures, even the smallest fish species.
Can Fish Form Friendships Across Species?
To say friendships would be a bit of a stretch, but fish can have social bonds and understanding with other species. This is mainly driven by survival and the aforementioned good memory that fish have.
This allows fish owners to set up community tanks where multiple fish species can co-exist together without being in a state of constant fear and anxiety. If you get it right, you can create a perfectly harmonious aquarium.
Once fish have the understanding they won’t be trying to eat each other, they can interact. Some groups, especially if they enjoy the same area of tank, can swim together and share the same spaces without any issues. It shows a social bonding but is usually more of a mutual understanding than friendship.
However, it’s vital to do your research when setting up a tank. There are plenty of aggressive fish species out there which aren’t friendly at all and will keep to their own kind. It’s important to remember all fish species are different and will have unique behavioral traits.
The Limits of Fish Friendships
Despite what we’ve said above, it’s wise to appreciate the limitations of fish friendships. Most animals are driven by their own needs and desires. Any interaction with other creatures is for their own gain.
Fish interactions are usually driven by survival needs. Unlike humans, they won’t form relationships based on shared interests or intimacy. However, the comfort that a familiar companion can give them can be akin to a form of friendship.
For humans, friendship requires the intention to be friends and the reciprocity that goes with it. These are cognitive abilities that most certainly go beyond fish. But while instincts may drive them, it’s clear fish are capable of showcasing many different social behaviors.
Implications for Aquariums and Fish Care
When you own an aquarium, it’s good to know how fish social behaviors impact the environment as it can be easy to make mistakes. The first port of call is always choosing compatible species that not only live harmoniously with each other but won’t get in each other’s way.
Overcrowding should always be avoided. Not only can it cause other tank issues, but it can create social stress. Without enough space, some fish which are usually placid and friendly can turn aggressive when they need to fight over territory.
You also want to encourage natural behaviors, such as hiding and shoaling. Some fish, such as tetras, need to be in a large group to feel most comfortable. Other fish, such as bettas, will be happy being on their own.
