Last update: November 2, 2022

Coolest Aquarium Fish

Are you of the opinion that only marine tank owners can raise cool yet weirdly exotic aquarium fish?

It is a myth, and in this article, we are attempting to change that mindset. 

When we talk about weird aquarium fish that will add vibrancy to your fish tank, we think of various saltwater fish species like Clownfish. There are a plethora of freshwater fish species that can add the same brightness, spark, and beauty to your fish tank. 

There are too many options to choose from. We will provide you with those cool aquarium fish options in this article. With the proper care tips, you can take care of your favorite pet with fins.

Reasons to invest in freshwater aquarium fish

  1. Less expensive. 
  2. Not that much prone to chronic diseases. 
  3. Easy to take care of. 

Taking care of a freshwater aquarium fish 

guppies and tetras

Your freshwater fish tank is the home of the fish living there. Hence, the environment should be healthy and clean at all times. As it is an enclosed space, you need some pointers to maintain it without any mishap. 

Here, we have listed essential tips for taking care of the ecosystem in which the freshwater fish will be living. 

  • Understand the importance of the nitrogen cycle

Using an aquarium filter by letting the nitrogen cycle kick in within six weeks is an important step. This filter consists of three distinct elements: a mechanical element, a natural element, and even a chemical element.

All the produced substances from the fish’s left-over food and the decomposed waste need to be processed. The filter arrangement does this processing. 

  • Know when it is time to introduce your fish to its aquarium

We understand that you are excited to dip all the weird aquarium fish into the water. However, you can’t do it when you feel like it. There is a way of introducing the fish to the aquarium. 

  1. Before you plunge into dipping the fish in the display tank, you need to switch off all lights. 
  2. Don’t let your fish get suffocated. How can you do that? All you have to do is equalize the temperature of water in the tank. Once you have done it, you can open the bag’s mouth with the fish and keep it open to allow the passage of air that the fish desperately needs. 
  3. Proceed on to determine the pH level of the water present in the aquarium and the bag containing the fish. 
  4. Use a net to put the fish into the tank water delicately. When you do it, you need to get rid of or discard the water in the bag. 

The bottom line is that you need to filter out the tank at least once every month. A bonus tip for you is that you should get rid of the dead leaves and algae accumulated over time. 

List of top five cool and weird aquarium fish for hobbyists 

1. Discus


It is relatively easy to recognize this calm fish that is a native inhabitant of the delta of the Amazon river. Its body is thin and resembles a disk.

Their eye color is either yellow or red. It might or might not be a weird aquarium fish, but it is a gorgeous one that will enhance any fish tank’s beauty. Their dorsal fins are noteworthy as well. 

If you are a first-time aquarist, then we would suggest you not take in this delicate fish. This fish needs experienced handling. For experienced aquarists, this fish is easy to take care of. The level of tank water for this species is 75 gallons minimum. 

Their daily diet consists of shrimp, algae, etc. 

Although the Discus species is very amiable and can get along with any other fish, it is best to keep the aggressive ones away from them. 

2. Wolf Cichlid

wolf cichlid

Two adjectives describe this bold fish species – brilliant and territorial. These beautiful swimmers need ample space to swim around. So, we suggest planning on taking care of this weird aquarium fish, then getting a 200-gallon water tank. 

Their scale can be of four colors – blue, purple, green, and black. 

This species isn’t easy to deal with on a day to day basis. They don’t like sharing their space with some other species. Also, they love to dig. Hence, don’t put live plants into the tank. 

Wolf Cichlids can adapt to their ecosystem easily. They also bond with their caretaker quickly. You will be able to take care of this species if you have had experience in the past. One more thing – their diet consists of bugs and bloodworms. 

3. Flowerhorn Cichlid

flowerhorn cichlid

It is normal to confuse wild cichlid with flowerhorn cichlid. We will help you to tackle this. You can differentiate by noticing a little red-colored horn-like protrusion at the top of the flowerhorn cichlids’ head.  

This species is exotic. You would adore its bright-colored body. 

Their personality is characterized by the urge to know and use their intellect. Like dogs, they love it when you pet them as they are interactive. They are also possessive about their owners. They won’t let you bond with other species. 

Your fish aquarium would light up if you dip this fish in the water. You have to invest in a 75-gallon fish tank if you want to raise flowerhorn cichlids. 

4. African Butterflyfish 

african butterflyfish

This species is a native inhabitant of the African rivers, and their history is weirdly captivating. Interestingly, they are the slowest moving fish.

Also, they are the oldest when it comes to changes in morphology. There has been zero change in the morphology of this fish in over a hundred million years. Cool, right? They are a type of weird aquarium fish. 

If you watch them from a certain distance, then they resemble beautiful butterflies. They don’t have wings. However, an illusion is created by their dorsal fins, caudal fins, and ventral fins. Their body color is a dark shade of brown. They can blend in with the plants because of the specks on the body. 

They can adjust to living with a whole community of a different kind of fish, but it won’t be wise to do so. Rather than this, keep them with fellow butterflyfish. Their diet, too, consists of shrimps and different types of frozen food items. 

5. Black Ghost Knifefish

Black Ghost Knifefish

The unusual look of this species makes them a weird aquarium fish when it comes to the list of most exotic freshwater fish species. They can’t adapt to dim and dull light. Their skin color is black, and the body resembles a knife. Hence, the name is self-explanatory. 

Their navigation process is very much like that of eels. They are timid and come out willingly only at night time. Thus, the fish tank must have enough hiding spots to make the fish comfortable to live in it. 

They will survive better in a 150-gallon freshwater aquarium. The diet includes worms, chopped meat, etc. They might be shy when it comes to interacting with other freshwater fish species.

One downside of owning these fish is that they are more prone to various diseases. You have to clean the aquarium frequently to keep them as healthy as they can be. 

List of coolest and weirdest aquarium fish 

1. Neon Tetras

neon tetras

This 1.25 inches long fish is considered to be the most prized possession of all fish lovers. Six of these can be kept together. When they are seen in a group of six, this blue colored fish with a red tail look splendid. They are a feast to your eyes. 

2. American Flagfish 

american flagfish

This fish is named after the colors of the American flag. They are tiny in size, only 2.5 inches, and are too easy to care of and fall in love with.

They don’t like to be singled out; they thrive better in a community of different types of fish. They take a particular interest in eating away all the algae present in the tank. 

3. Peacock Gudgeon

Peacock Gudgeon

This species is well-known for the riot of colors on its body. This characterization makes the fish one of the coolest freshwater aquarium fish. They prefer peace over any kind of ruckus.

Peacock gudgeon breeding can be done in fish tanks that have an optimum filter system. This omnivorous species can feed on dried meat, shrimps, and even bloodworms. They can live for a maximum of five years. 

Final Words

Hopefully, you have fallen in love with some or all of the coolest aquarium fish mentioned in this article.

If you have developed strong feelings of love for them, then make sure you give a bit of your attention to these strikingly stunning creatures.  A fish with a special diet needs to be a territorial fish in personality. This list has a fish for every kind of hobbyist.

Since the list is so diverse, you can find which fish will get the best shelter in your fish display tank at home. Having said that, let us pose a question to you. Is there any weird aquarium fish that deserves a place on this list?

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

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