Is it Cruel to Keep Fish in a Tank?

Is it Cruel to Keep Fish in a Tank?

Here are the pros and cons of keeping a wild fish in a tank. We have explained all the reasons in detail.

Is it Cruel to Keep Fish in a Tank? Yes, it is cruel to keep a wild fish in a water tank. The wild fish becomes vulnerable within two to three days of their life in an aquarium. The incompatible fish and tank lead to the death of fish.

Is it Cruel to Keep Fish in a Tank?

Multiple reasons play their part in the cruel behavior. The fish become uncomfortable and go through feelings.


This can cause stress and the fish can become lazy and stop swimming. The mental shocks of water change and random food particles also generate the worst environment. It is cruelest to keep a natural habitat fish in an enclosed aquarium.

The stressful phases vary from lack of diet to inappropriate bumping on the rocks, you should know techniques to calm down a stressed fish. They come in an attacking situation, and it is not suitable for other tank mates of the water tank.


Wild fish become sad in the aquarium and this can affect their health. They will stay in one place and they do not find happiness in a constant and irritating surrounding. The lack of greenery in the water tank makes them frustrated and uncomfortable.

They express their emotion by folding themselves. Inappropriate swimming becomes a habit in such a worst situation. They miss their wild and freshwater habitat, and it makes them frustrated. 

Wild environment to tank

One of the most appealing species are the habitants of freshwaters. They live and survive in oceans, rivers, and lakes with greenery and swimming areas. When you keep them in a small to medium tank, and they become annoyed. 

Initially, they try to adjust to moderate water conditions but eventually, the fish becomes furious. They avoid all the feed in the tank.

It is their way of showing that they are not settling in a small habitat. Few of them die within days when you bring them from wild waters to home aquariums. 

Blindness due to chlorine

The keepers of aquariums clean their tank’s water with chlorine. The chemical is beneficial for the water inside the tank, but it is not suitable for wild fish.

They suffer from conditions like the blurred vision the soreness of the eyes. In some cases, the fish lack its eyesight and becomes a blind fish. 

They cannot protect themselves from rigid rocks and other decorative stuff of water tanks. The blindness in pet fish is not advisable as it is deadly for other mates as well. 

Bored fish

In freshwater habitats like lakes and rivers, the fish have a lot of fun activities. They swim and compete with other natural water habitats.

It keeps them happy and lively all the time, but in the water tank, the situation changes. The enclosed water boxes provide the least space for swimming. 

The fish strike in the tank’s wall right after the transfer. They become bored and uncomfortable. Many fish fall ill due to a lack of activities and fun routines. 


Separation from the family and other mates is a cruel act for a fish. They immediately lose all of their energy when you bring them to aquariums.

The invertebrate misses its family and other fish of natural water source. It is such a harmful act that a few numbers of fish survive with it.

A maximum number of them die due to this sudden change and its shock. You cannot keep a wild and free fish in an aquarium away from its family. It cannot survive for even three days and die in a miserable condition. 

Poor maintenance

The worst regulatory patterns of an aquarium are one of the cruelest acts for a fish. People leave their tanks without changing the water conditions.

It happens for weeks and even months, and pet fish are mostly freshwater creatures. They find it shocking and inappropriate.

Initially, you can observe mood swings in them, and they avoid the food. It makes them lazy and sick, and the water becomes dirtier with time. 

The tank’s plants damage with the worst water conditions, and it turns into a smelly and miserable state.

Mixed fish species

Few species are selective, and they cannot live in a mixed tank. If you are aware of the breed and its nature, never do this to your pet fish.

People putting the choosey tiny invertebrate in the mixed fish tank are one of the cruelest acts. There is no justification for such a blunder because it is enough to shock them.

They die or get incurable diseases. Once you remove it from such a tank, and they survive. Always avoid this action and protect your fish from mixing with other species. 

Injuries and egg loss

They protect themselves and their new generation from predators. When you put such angry fish in a calm water tank with other mates, the situation changes drastically. 

The water tanks convert into a war land, and lack of observation leads to bloodshed. The angry species attack the calm mates without any reason.

Pushing and bumping happen without any significant reasons. The fighting fish damages the eggs of female mates. Calm fish becomes helpless, and they lose their eggs which is not suitable for generations. 

Mix breeding

It is unacceptable to keep different breeds in one tank. It is not advisable for those species that are non-selective naturally because they inter-breed.

As a result, such species originate that cannot survive, and even if they then have no classification.

Few live without any scientific and generic name, and no fish species encompass them in their species family. The pet keepers never buy such mixed breeds, and they die due to lack of attention and care. 

Competition for food

It is not advisable to ever place the invertebrate that remains hungry all the time. These are not obese species, but they keep on eating. Few species belong to this category, and they fight for their food.

Putting such species in a tank full of other peaceful species is cruel. It harms the lifespan and survival of other tiny mates. Few of them die due to lack of food. The competition for food causes injuries and bullying. 

Bad aquarium

The bad aquarium includes the worst tank conditions like broken glass, dirty water, and chemicals. 

The natural plants and decoration create a net of fungi on both sides of the tank. It is not a suitable environment for freshwater and marine fish.

They take it as an unjust act because the lakes and fresh rivers offer them all the necessities of life. In a small water tank, the situation turns worst when the owner keeps them inside.

Initially, they swim a lot to show their discomfort, and they stop swimming. Most of them die due to inadequate environmental conditions of the water. 

Crowded aquarium

The oceans and rivers comprise plenty of fish, but the area is vast. The fish get maximums space for swimming and finding food.

Each of them stays at a specific distance from the other. These water habitats are a mixture of wild and peaceful fish. In a small to medium tank, the situation changes. 

When you put such invertebrates in an enclosed environment with multiple mates, they become frustrated. Survival becomes difficult, and they find places to hide.

The over crowd leads to improper swimming, and the water changes into the dead source. Suffocation enhances up to the limit, and fish gills stop working.

Constant feeding

Constant feeding is a cruel act of the owner in a large fish tank. These tiny creatures cannot eat all the time, but the food particles attract them.

They capture most of the food, and the owner finds it fascinating. Overfeeding is not beneficial for their health.

They poop more than casual, and it makes the water dirtier. Many toxic gases like carbon monoxide and carbon dioxide accumulate in the tank’s water. The sicknesses prevail, and the dying rate touches the highest peak. 

Poor growth

Few tiny creatures of freshwater and natural habitats stop growing. The reasons are casual, but few people get emotional.

They decide to pet such fish and put them in enclosed water containers. The fish does not like such changes, and the growth retards in them.

The detachment of the parent habitat makes them homesick. It stops moving and settles itself in the bottom.

Low levels of oxygen

The fish’s swimming keeps the water alive, and they jump to the surface and gain oxygen from natural air.

They swim with maximum power, but the crowd in the tank does not allow it. It causes frustration in them, and they stop swimming.

The natural oxygenations top and suffocation enhances. The respiratory organs of the tiny creatures stop worming, and wild fish can die in the tank.

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