Can a Betta Fish See in the Dark? Answered

If you are involved in the aquarium world, you have come across betta fish. They are some of the most popular fish in aquariums, and for a good reason. Their bright and vivid colors and their social and playful nature make them some of the most desirable fish for aquarists. 

Betta fish are a part of the gourami family. Unfortunately, their liveliness is often taken beyond the limit when they come across another species of fish trespassing their territory. They are highly territorial fish and will fight to keep their own. In fact, at times, if two betta fish are kept in a tank, there is a good chance that they may end up killing the other. 

Betta fish are territorial. This means they are also hunters at times. In these moments, they rely on their sight to guide them. It is the primary sense they use to come out victorious and survive a fight. Years of depending on their sense of sight mean they have a unique set of eyes that have advanced to the point of seeing nearly as much as humans do. So let’s take a dive and figure out more about their sight and how they fare in the dark.

Are betta fish OK in the dark?

Are betta fish OK in the dark

It doesn’t matter what fish you have in your aquarium. Your priority should be to try and mimic their natural environment as close as you can. Now, when we talk about Betta fish, in particular, it is recommended that they have a little bit of ambient lighting to simulate a sort of Day / Night cycle. 

Now, betta fish come from the rice fields in Vietnam. This environment is murky, thanks to the clay-like soil that acts as a substrate. The Betta has a relatively fine sense of vision in murky water. However, their sense of vision in the dark is entirely another topic. In pure darkness, their vision does not work well at all. Betta fish cannot judge depth, and their vision is similar to being able to see through only one eye. Again this is a testament to evolution. In addition, Betta fish usually spend their nights sleeping, meaning that they do not require excellent sight in the dark.   

Betta fish do not critically require light, but they will be healthier if they are exposed to a cycle of light and dark.  

Do betta fish need light at night?

Do betta fish need light at night

Come nighttime, and betta fish do not require light. On the contrary, they prefer the dark at this time. They need both light and darkness to function efficiently, both mentally and physically. These fish require the night to rest and recharge their energies. The same happens in the paddy fields, their natural habitat. 

Too much exposure to light could also stress out the fish. This is not something that you would like to happen. This is also the only time fish as lively and playful as the betta rest. Rest is a must after a long day of swimming around.

Do Bettas Like Being in the Dark?

Betta fish do not prefer being in either the dark or light. They require exposure to both for a healthy body clock that runs over an entire day. Betta fish experience much better sleep in the dark than if the lights were on. Sleep is a loose term for it, but betta fish go into a restful state where their metabolic rate and breathing are reduced. In addition to this, their brain function also slows down. 

This is also true for most other fish. Apart from getting rest, it also helps them develop their immune system and build resistance to illnesses. Another fact that is quite fascinating is the fact that betta fish do not have eyelids. 

In the natural habitat, besides paddy fields, exposure to sunlight also leads to the production of algae. This is one of the natural food sources for betta fish. The presence and production of algae in aquariums are also necessary. This happens because of light exposure.

Is it OK to Leave my Betta Fish in the Dark?

When someone thinks of betta fish, they might assume that betta fish would be perfectly alright on its own in a dark tank. This is a common misconception that arises because of the territorial nature of betta fish. However, this is not the case. 

In the dark, betta fish do not have perfect vision. Their vision in the dark has not evolved enough for them to be able to use it effectively. Also, we spoke about the importance of having a regulated light and dark cycle for betta fish. They need this change for both their physical and mental well-being. 

Ideally, over 24 hours, betta fish need to be exposed to a minimum of fourteen hours of light. However, the remaining time, they need the dark as well. This cycle helps regulate the internal body clock of the fish. Therefore, it is not OK to leave betta fish in the dark for extended periods. 

Why Betta Doesn’t Run Into Other Decorations In The Dark?

Why Betta Doesn't Run Into Other Decorations In The Dark

As we earlier mentioned about how betta fish have developed their vision over generations. As they have evolved, their eyes have become similar to that of humans. However, there are also a lot of differences.

Betta fish have tiny irises as compared to humans. Their irises are also nowhere near being as quick as ours. This is because the betta fish need time to adjust to changes in the intensity of light. On the other hand, humans can quickly adapt to the changes in light intensity. 

However, betta fish have a sixth sense that allows them to sense objects in and around them in the dark. This is credited to a lateral line seen along the side of their body. This lateral line houses multiple receptors that are sensitive to pressure. It works somewhat like radar, except that instead of radio waves, it is water pressure that allows for mapping. This gives Betta the ability to understand their surroundings without being able to see them.

Can Betta Fish Eat In The Dark?

We mentioned earlier that betta fish could see relatively well enough in murky water but do not have good vision in the dark. This means that betta fish will not even be able to see food in the aquarium when it is dark. Therefore, eating something without even seeing it is not possible for the fish. 

Albeit, the fish can see relatively well in murky water. This means that if there is some form of a light source, even a very dim one, the Betta will be able to see the food. Once it sees the food, the Betta will try and eat it. 

Can Betta Fish See Their Food in the Dark?

Can Betta Fish See Their Food in the Dark

In absolute darkness, betta fish have little to no vision. This means that betta fish will not be able to see their food in the dark. They need a little bit of light to make out shapes and objects. They can see relatively well enough in murky water, but not as well as in clear water. Their perception of depth is amiss, and their vision is poor. At times it may even seem like their vision is somewhat monocular.   

Can Betta Fish Sleep In The Dark?

Yes, betta fish do have the ability to sleep in the dark. However, they cannot sleep when there is light. This is mainly because they do not have eyelids, and the light disturbs them. Exposure to light stimulates betta fish and makes them quite active. The betta fish gets very stressed out if it is exposed to lights for extended periods. 

If we now look at the other side, if a betta fish is kept in the dark, the fish will stay inactive. This is because they need a bit of both light and darkness to stay healthy, both mentally and physically. Ideally, they have 12 hours of the morning and 12 hours of dark. This cycle is called the Circadian cycle. 

Wrapping Up

To sum it all up, we can undoubtedly say that betta fish have good eyesight, given that the conditions are favorable. In murky water, they can make their way from point A to point B without too much trouble. The real problem comes up when there is absolutely no light. In such a situation, the Betta will not be able to see anything at all. 

We can take away from this because it is essential to have a Circadian cycle (a 12-hour shift between light and dark) for betta fish to be healthy and maintain their lively and social nature.

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