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41 Amazing And Cool Freshwater Fish For Your Tank

Want to find exciting and cool freshwater fish for your aquarium? Here are 41 of our favorites that will make your tank shine!

By Andy Birks
Last updated on

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cool freshwater fish

Over the years the team and I have owned most of these fish between us. So we spent a good while discussing our favorite cool freshwater fish!

The majority are easy to keep and great for a community tank. I’ve also added some striking but tricker ones if you have more experience. You’ll see I’ve defined the care level needed against each fish.

It’s a long list so use the table of contents below if you want to jump to a particular fish.

So let’s dive in and I’ll show you that freshwater fish can be just as cool and amazing as marine ones!

1. Peacock Gudgeon

Scientific Name: Tateurndina ocellicauda. Family: Eleotridae.
  • Care Level: Easy
  • Max. Size: 2.5 to 3 inches
  • Temperament: Peaceful
  • Min. Tank Size: 15 gallons
  • Water Temperature: 72-79° F

The many bright colors of the Peacock Gudgeon make this a very cool freshwater fish!

Make sure you have a well-planted tank with plenty of hiding spaces. Whilst they are very social fish and great for a community aquarium, they do like time to themselves.

It’s best to have one male and two or three females in a tank, as males can be territorial with other males [1].

Peacock Gudgeons are omnivores although they lean towards a meat-based diet. Feed them frozen or freeze-dried protein-rich foods like brine shrimp or bloodworms [2].

Suitable tankmates include barbs, kuhli loach, tetras, cory catfish, and rasboras.


2. Boeseman’s Rainbowfish

Scientific Name: Melanotaenia boesemani. Family: Melanotaeniidae. Image source: “Boeseman’s Rainbowfish” by Chun’s Pictures is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 4 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 72-77° F

The Boeseman’s Rainbowfish is a perfect choice for a striking freshwater fish.

A well-planted tank with plenty of room to swim will show off these fish to the best effect.

They are omnivorous and should be fed flakes, and live and frozen foods which will help enhance their color [3].

They are very social and should be kept in a school of at least six to eight fish.

The Boeseman’s Rainbowfish will also do well in a community tank. Barbs, tetras, cory catfish, danios, gouramis, guppies, or loaches would all make excellent tankmates.


3. Paradise Fish

Scientific Name: Macropodus opercularis. Family: Osphronemidae. Image source: “Paradise fish male” by Daniella Vereeken is licensed under CC BY 2.0
  • Care Level: Intermediate
  • Max. Size: 4 inches
  • Temperament: Semi-aggressive
  • Min. Tank Size: 30 gallons
  • Water Temperature: 61-79° F

With its colorful flowing tail fin, the Paradise Fish is another cool freshwater fish.

Keeping a single Paradise Fish can make them more prone to startling [4]. But you need to be careful what tankmates you keep them with.

You can keep a single male with several females, or a group of females together. But you should only keep one male per tank.

In a community tank keep them with other larger semi-aggressive fish. Firemouth cichlids are a good example.

Paradise Fish need a high-protein diet that can include flake foods, tubifex, and brine shrimp.


4. Honey Gourami

Scientific Name: Trichogaster chuna. Family: Osphronemidae.
  • Care Level: Easy
  • Max. Size: 2 inches
  • Temperament: Peaceful
  • Min. Tank Size: 10 gallons
  • Water Temperature: 72-82° F

The dazzling golden color of the Honey Gourami would make it a delightful addition to your tank.

Make sure your tank is well-planted, including floating plants. Don’t overdo it though as they need access to the surface to breathe.

I’d recommend keeping around four to six together as they do enjoy the company of their own kind. 

They are equally suited to a community tank though. Tankmates should be peaceful and could include guppies, platies, or small tetras.

Algae-based flake food, tubifex, or brine shrimp will provide the right diet. If breeding them, increase protein-based foods to help with reproduction and growth [5].


5. Crowntail Betta

Scientific Name: Betta splendens. Family: Osphronemidae. Image source: “CT Multicolour M – Betta-Online” by Daniella Vereeken is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 4 gallons
  • Water Temperature: 75-86° F

The Crowntail Betta is one of the most popular choices of freshwater fish and it’s easy to see why. Their striking colors and beautiful fins make them mesmerizing!

It’s well-known that you can’t keep more than one male as they will fight. But this can also apply to females [6]. If you keep a single betta you’ll find it’s often a very peaceful fish. 

A single male should be kept in a 5-gallon filtered tank. Make sure it has plenty of plants and decorations to keep them happy. You can also keep them with certain peaceful community fish such as kuhli loaches, or cory catfish.

Bettas are carnivorous. Feed them betta-specific pelleted food, bloodworms, or brine shrimp.


6. Elephant Ear Betta

Scientific Name: Betta splendens. Family: Osphronemidae.
  • Care Level: Easy
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 4 gallons
  • Water Temperature: 75-86° F

A sometimes less considered but cool freshwater fish is the Elephant Ear Betta. Its dramatic pectoral fins which give the fish its name will look stunning in your aquarium.

The Elephant Ear Betta has similar needs as other betta fish. Don’t keep males in the same tank, but you can keep females together with caution. They can also be kept with other suitable community fish.

You should provide pelleted betta food along with live or dried meat treats. Allowing your betta to feed solely on vegetation will not provide the nutrients it needs [7].


7. Cherry Barb

Scientific Name: Puntius titteya. Family: Cyprinidae. Image source: “Cherry Barb” by Lakpura LLC is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 2 inches
  • Temperament: Peaceful
  • Min. Tank Size: 25 gallons
  • Water Temperature: 74-79° F

The Cherry Barb is often overlooked when compared with other barbs. But it is a beautiful fish with a gorgeous deep red color.

It’s easy for beginners with a peaceful temperament and is perfect for a community tank. 

The Cherry Barb is a shoaling fish and you should keep them in a group of at least six. Other tankmates that work well are danios, gouramis, rasboras, mollies, loaches, and hatchets.

They are omnivores and should be fed a variety of vegetable and meat-based foods. Quality flake food with high carotenoid levels can help enhance its color [8]. You can usually find this information on the list of ingredients.


8. Odessa Barb

Scientific Name: Puntius (Pethia) padamya. Family: Cyprinidae.
  • Care Level: Easy
  • Max. Size: 3 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 74-79° F

The Odessa Barb’s shimmering stripe makes it another cool freshwater fish for your tank.

Planting should be one of your main considerations with these fish. They originate from South East Asian waters rich in vegetation [9]. I used to keep Odessa’s and found hornwort and water wisteria worked well.

They are peaceful fish and great for a community tank. I kept mine with rasboras, longfin tetras, and a couple of plecos. Other excellent choices include barbs or danios. Keep them in a group of no less than six together.

They are omnivores and will eat fish flakes as well as freeze-dried or frozen meaty foods.


9. Celestial Pearl Danio

Scientific Name: Danio margaritatus. Family: Cyprinidae. Image source: “Celestial Pearl Danios” by CheepShot is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 2 inches
  • Temperament: Peaceful
  • Min. Tank Size: 10 gallons
  • Water Temperature: 73-77° F

The Celestial Pearl Danio has become hugely popular since its discovery in 2006 [10]. And with its gorgeous colors, it’s easy to see why!

Their natural habitat is shallow, vegetated ponds with low water movement [11]. You’ll need a well-planted tank with driftwood or rocks to mimic these conditions.

Keep them in groups of five or six as they like to shoal. Some of the best tankmates include guppies, cory catfish, or even some killifish.

Daphnia is a good food choice as it will help the coloration of these omnivores. You are also better to use sinking food with these fish as they rarely visit the surface.


10. GloFish Tetra

Scientific Name: Gymnocorymbus ternetzi. Family: Characidae.
  • Care Level: Easy
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 10 gallons
  • Water Temperature: 72-82° F

If you are looking for stand-out fish with the brightest color then look no further than GloFish! 

Exciting and easy to keep, they are incredibly popular across America. As well as tetras, the GloFish brand includes danios, barbs, and zebrafish amongst others.

Some people wrongly believe they are made fluorescent using dyes. But they are actually bred to glow using genetics which doesn’t affect their systems [12].

California initially banned their sale due to concerns about genetically modified fish. This was reversed in 2015 allowing their sale in line with the rest of the country [13], [14].

These tetras are best kept in small schools and will live happily with other peaceful fish. Feed them quality flakes and live foods such as daphnia or mosquito larvae.


11. Emperor Tetra

Scientific Name: Nematobrycon palmeri. Family: Characidae.
  • Care Level: Intermediate
  • Max. Size: 1.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 10 gallons
  • Water Temperature: 72-77° F

These are another tetra you may not think of straight away but are definitely a cool addition to your tank!

As a schooling fish, you should keep them in a group of five of six with a single male. They are great for a community tank too. The best tankmates would be other peaceful species. Danios, rasboras, corys, or guppies are all good options.

They are easy to feed, accepting commercial flakes or pellet foods. As omnivores, you can offer daphnia, bloodworms, or brine shrimp for added protein.

If you are looking to breed these fish consider the lighting in your tank. Some research suggests that raising them under red or blue lighting can result in more females [15].


12. Wrestling Halfbeak

Scientific Name: Dermogenys pusilla. Family: Zenarchopteridae. Image source: “Dermogenys17” by Ahsan al hidayat is licensed under CC BY-SA 4.0
  • Care Level: Intermediate
  • Max. Size: 3 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 75-79° F

If you want a cool freshwater fish that’s a bit different the Wrestling Halfbeak could be for you. Its unusual elongated bottom jaw certainly makes it a stand-out fish.

This fish is a livebearer and so gives birth to young rather than laying its eggs [16], [17].

You should keep this fish in a shoal of at least six with a single male. They also make a good community fish. You could keep them with smaller rainbowfish, freshwater gobies, or other livebearers.

As carnivores, you should feed them live or frozen foods. Tubifex or bloodworms are good options, along with quality flake food.


13. Chocolate Oranda Goldfish

Scientific Name: Carassius auratus. Family: Cyprinidae.
  • Care Level: Easy
  • Max. Size: 10 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 65-75° F

The deep rich colors of this fish give it a particular beauty that makes it very special.

These fancy goldfish will continually forage in the substrate. So choose larger grain sand or rounded gravel to avoid damage to their mouths or fins. 

These fish are omnivores, and you can provide a range of pellet-based and frozen foods. But keep the meaty foods as a treat as protein should be limited to around 30% of their diet.

If breeding you can start the larvae on brine shrimp and then Moina (water flea) after about a week. After two weeks provide bloodworms to build their protein levels as they grow [18].


14. Bubble Eye Goldfish

Scientific Name: Carassius auratus. Family: Cyprinidae. Image source: “Bubble Eye goldfish” by Jordan Hartig is licensed under CC BY-SA 3.0
  • Care Level: Intermediate
  • Max. Size: 5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 20 gallons
  • Water Temperature: 65-80° F

A friend of mine used to own Bubble Eyes and they were certainly very cool fish. The distinctive sacs under each eye give them a unique look!

But they are delicate. So use a rounded substrate and avoid pointy plants that may cause damage. An under gravel filter is also a good option to prevent them from brushing against it.

Around 72° F is best for the Bubble Eye. Goldfish need a slightly cooler temperature than other tropical fish. Too high and they can be more prone to infection [19].

Again, offer pelleted foods that sink to the bottom of the tank with the occasional meaty treat.


15. Electric Blue Jack Dempsey

Scientific Name: Rocio octofasciata. Family: Cichlidae.
  • Care Level: Intermediate
  • Max. Size: 10 inches
  • Temperament: Aggressive
  • Min. Tank Size: 55 gallons
  • Water Temperature: 78-82° F

This fish has long been one of my favorites. Its color is absolutely amazing!

The Electric Blue can be harder to track down than the standard Jack Dempsey but I think it’s worth it.

The Jack Dempsey originates in the slow-flowing rivers of Central America [20]. Provide a well-planted tank with rocks and driftwood to mimic these conditions.

While these fish are beautiful they are a predatory species and often aggressive. Do not keep them with smaller fish which they could easily prey on. Instead, you could keep three or four Jack Dempseys together which would make for a gorgeous display.

You can feed this carnivore on tubifex, bloodworms as well as live fish.


16. Gold Marble Angelfish

Scientific Name: Pterophyllum scalare. Family: Cichlidae.
  • Care Level: Easy
  • Max. Size: 6 inches
  • Temperament: Semi-agressive
  • Min. Tank Size: 30 gallons
  • Water Temperature: 75-82° F

Angelfish are one of the more popular statement fish that may come to mind when stocking your tank. 

The Gold Marble Angelfish has beautiful orange and black marbling like koi. But there are many other varieties.

Like other cichlids, these fish can be quite aggressive. You can keep them in small schools of around four as long as your tank is big enough. But be prepared to remove some if they become too territorial.

Although they are omnivores, they do need a good level of protein. So feed them live or frozen food like tubifex or bloodworms. This is particularly true if you intend to breed them as live food should form the basis of the young’s diet [21].


17. Electric Yellow Lab

Scientific Name: Labidochromis caeruleus. Family: Cichlidae. Image source: “Labidochromis caeruleus” by brian.gratwicke is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 6 inches
  • Temperament: Semi-aggressive
  • Min. Tank Size: 50 gallons
  • Water Temperature: 72-82° F

The intense yellow color of this cichlid makes it a particularly cool freshwater fish. 

Although one of the more peaceful cichlids, they can be aggressive when threatened. So keep them with other Mbuna species such as Peacock Cichlids.

They like hiding spaces to swim in and out of so set them up with driftwood or rocks and plenty of robust plants.

These fish will eat vegetation as well as meats, but you should keep their protein levels above c. 35% [22]. Provide shrimp and bloodworms to achieve this. 

You can also give high carotene foods to help maintain their color.


18. Rainbow Kribensis

Scientific Name: Pelmatochromis pulcher. Family: Cichlidae. Image source: “Pelvicachromis pulcher (male)” by Tino Strauss is licensed under CC BY-SA 3.0
  • Care Level: Easy
  • Max. Size: 4 inches
  • Temperament: Semi-aggresive
  • Min. Tank Size: 50 gallons
  • Water Temperature: 72-82° F

The Rainbow Kribensis is another amazingly colorful fish and a great choice.

Whilst this can be an aggressive fish, it has some interesting traits when breeding. Studies have shown that they will sometimes adopt and care for the fry of other Kribensis. It is thought this adaptation may be to reduce predation on their own young [23].

Overall though this is one of the more peaceful species of cichlid. You can keep it in a community tank with barbs, tetras, or certain catfish.

Rainbow Kribensis is an omnivore. Provide them with a higher proportion of vegetable-based foods supplemented with meat options.


19. Blue Discus

Scientific Name: Symphysodon sp. 1. Family: Cichlidae. Image source: “Blue Discus in Tropicarium” by wuestenigel is licensed under CC BY 2.0
  • Care Level: Intermediate
  • Max. Size: 10 inches
  • Temperament: Peaceful
  • Min. Tank Size: 55 gallons
  • Water Temperature: 79-86° F

Discus are undoubtedly a very cool fish for your freshwater aquarium. 

Originating from the central Amazon region, the range of colors and patterns across the four main species is broad [24]. You therefore have the option of a striking single species tank. 

Discus will also live happily with other species that thrive on higher temperatures. Cardinal tetras, clown loaches, or dwarf cichlids are all good tankmates. 

They are peaceful fish, and whilst I wouldn’t recommend them to an absolute beginner, they are often easier to care for than many say.

Discus are carnivores. So feed them freeze-dried or frozen meat-based foods. You should supplement this with commercial flakes for additional minerals.


20. Cockatoo Dwarf Cichlid

Scientific Name: Apistogramma cacatuoides. Family: Cichlidae.
  • Care Level: Intermediate
  • Max. Size: 2.5 inches
  • Temperament: Semi-aggressive
  • Min. Tank Size: 30 gallons
  • Water Temperature: 72-86° F

The deep blue and orange fins of the Cockatoo Dwarf Cichlid will really create interest in your tank!

They need an aquarium that is densely planted in groups to give hiding spaces but plenty of room to swim too.

Try to keep them at the higher end of the temperature range – around 79° F. Studies have shown that they tend to be more active and also less aggressive around this temperature [25].

Except for when breeding, they are reasonably peaceful cichlids. Suitable tankmates include the kuhli loach, dwarf gourami, and some rasboras.

This fish is a carnivore. Feed them with tubifex, brine shrimp, bloodworms, and flake food to balance their diet.


21. Duboisi Cichlid

Scientific Name: Tropheus duboisi. Family: Cichlidae.
  • Care Level: Intermediate
  • Max. Size: 5 inches
  • Temperament: Aggressive
  • Min. Tank Size: 50 gallons
  • Water Temperature: 72-82° F

The Duboisi Cichlid is a really cool freshwater fish that is often overlooked. 

Juveniles are black and covered with bright spots. As they age they lose these spots and a deep yellow band develops just behind the head. This later becomes blue [26].

Bear in mind that these can be aggressive fish. You should keep them in shoals of at least six consisting mainly of females.

They are herbivorous and should be fed a quality flake or pellet food. You can also provide vegetable matter such as dried seaweed to supplement.


22. Oscar Fish

Scientific Name: Astronotus ocellatus. Family: Cichlidae.
  • Care Level: Experienced
  • Max. Size: 12 inches
  • Temperament: Semi-aggressive
  • Min. Tank Size: 70 gallons
  • Water Temperature: 79-86° F

Not only do Oscar fish have attractive and unusual colors, but they also have an intelligent character.

But bear in mind these are big fish! They grow quickly too – around an inch per month until they are about twelve inches long.

They are a temperamental cichlid and I would only recommend them if you have some experience. 

A species-specific tank is the safest bet when keeping these fish. If you are set on a community tank you would need to keep other large cichlids that can compete, such as Jack Dempsey.

The Oscar is a predatory carnivore that will eat large quantities. You can give commercial cichlid pellets, tubifex, and bloodworms. Frozen or dried shrimp are another good option and are beneficial for growth, coloration, and as an antioxidant [27].


23. German Blue Ram

Scientific Name: Mikrogeophagus ramirezi. Family: Cichlidae. Image source: “GERMAN BLUE RAM” by sapienssolutions is licensed under CC BY 2.0
  • Care Level: Experienced
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 72-79° F

The German Blue Ram is a gorgeous cichlid with vivid orange, yellow, black, and blue colors that will stand out in any tank.

They are one of the more peaceful cichlids and can be kept with a variety of tankmates. You could house them with dwarf gouramis, clown loaches, guppies, mollies, or discus.

However, these are fish for experienced aquarists as care and water quality has to be spot on. 

Experience is also recommended when it comes to breeding. You should find a pair will start to follow each other during courting. Often males are more attracted to females with a brighter pink underbelly [28].

Feed these omnivores on shrimp, bloodworms, artemia, and smaller amounts of flake foods.


24. African Butterfly Fish

Scientific Name: Pantodon buchholzi. Family: Pantodontidae.
  • Care Level: Intermediate
  • Max. Size: 5 inches
  • Temperament: Aggressive
  • Min. Tank Size: 40 gallons
  • Water Temperature: 75-86° F

We have to include the African Butterfly Fish here as a cool and unusual freshwater fish.

It’s called a flying fish because it can leap out of the water as an escape mechanism [29]. So if you want to keep it make sure your tank has a lid!

You’ll want to provide a long aquarium instead of tall as they spend most of their time at the surface. Your tank should have plenty of surface cover plants and have little current. 

They can be aggressive particularly when competing for food. That said they can be kept with certain tankmates including cory catfish, kuhli loach, or bristlenose plecos.

They are a carnivore and you can feed them brine shrimp, freeze-dried, or other live foods.


25. Dwarf Chameleon Fish (Badis Badis)

Scientific Name: Badis Badis. Family: Badidae.
  • Care Level: Intermediate
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 20 gallons
  • Water Temperature: 73-79° F

Badis Badis is a very cool freshwater fish – it can change color depending on its mood!

When it’s comfortable its colors can be bright and vibrant but they fade when stressed. Hence its name the Chameleon Fish.

These fish have a very elaborate mating behavior. The male will stay in his burrow and the female will join him to start spawning. The male first attacks the female but this soon gives way to mating behavior. Spawning takes place and the eggs fall to the floor [30].

The Chameleon Fish tends to do better in a community tank as it can be more territorial with its own kind. Suitable tankmates can include larger tetras and angelfish in a large tank.


26. Endler’s Livebearer

Scientific Name: Poecilia wingei. Family: Poeciliidae.
  • Care Level: Easy
  • Max. Size: 1 inch
  • Temperament: Peaceful
  • Min. Tank Size: 10 gallons
  • Water Temperature: 64-82° F

You can find this beautiful little fish in a range of color variations. This includes red stripe, emerald, and sunburst cobra.

One of the cool things about this fish is during mating the male is able to pick out its best and most colorful side to attract females [31].

They are about the easiest fish to keep on this whole list and so perfect for you if you are starting your first tank.

Endler’s Livebearer is an omnivore. So provide an algae-based flake food along with brine shrimp, tubifex, or daphnia.

They are peaceful and you can house them with tetras, glassfish, danios, betta fish, and minnows. But don’t keep them with any aggressive species that may prey on them.


27. Koi Swordtail

Scientific Name (Type name): Xiphophorus hellerii. Family: Poeciliidae.
  • Care Level: Easy
  • Max. Size: 4 inches
  • Temperament: Peaceful
  • Min. Tank Size: 20 gallons
  • Water Temperature: 64-82° F

Koi Swordtail come in various varieties. Show Koi display the oranges, reds, and black over a white body like koi carp.

They tend to swim in the middle or near the surface of the tank. As with other swordtails, these fish are jumpers so you will need a lid for your aquarium.

They are very social and great for a community tank. You can house them well with other similar fish like mollies and platies, or with peaceful cory catfish.

These fish are omnivorous. You can feed them algae-based flakes, pellets, frozen food, bloodworms, or brine shrimp. Krill and spirulina are also good options. They contain high carotenoid levels which help with color and growth [32], [33].


28. Fancy Guppy

Scientific Name: Poecilia reticulata. Family: Poeciliidae. Image source: Image by jorge.correa is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 10 gallons
  • Water Temperature: 76-80° F

One of my favorite freshwater fish is the humble guppy. With its mesmerizing pattern and gorgeous color, it is a truly beautiful fish. And there are over 300 varieties!

Guppies are fairly hardy and mature quickly. This makes them fantastic for beginners and seasoned aquarists.

Guppies breed like crazy! So if you don’t want any fry I would recommend keeping all males. If you do want to breed them, keep at least two females to each male guppy.

Tankmates such as platies, mollies, and tetras are all good choices for a community tank.

You can feed these omnivores quality commercial flake food, bloodworms, and tubifex. If you are looking to breed your guppies you can provide them with spirulina. Studies have shown that this can help induce breeding [34].


29. Dalmatian Molly

Scientific Name: Poecilia latipinna. Family: Poeciliidae.
  • Care Level: Intermediate
  • Max. Size: 4.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 68-82° F

Mollies can often be thought of as fairly common, but not this Dalmation Sailfin! Its beautiful orange tones are offset by the striking black.

These larger mollies need plenty of space and should be kept in a group of no less than six, ideally around twelve. A well-planted long tank, rather than tall, would show off these fish wonderfully.

They need hard, alkaline water which is high in carbonates. You can buy commercial products to do this job, or adding crushed shells also works well. 

Getting the water conditions right is particularly important if you are breeding these fish. Interestingly, both males and females favor larger mates when breeding [35].


30. Bumblebee Goby

Scientific Name: Brachygobius doriae. Family: Oxudercidae.
  • Care Level: Intermediate
  • Max. Size: 1.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 10 gallons
  • Water Temperature: 72-84° F

These fish may be small but they are a really cool option for your freshwater tank.

They are generally peaceful and social, but can sometimes be a little territorial.

You should keep a reasonably sized group of eight or more. This way any squabbles are more likely to be distributed through the group than focused on one individual. 

If one is injured you may see the others change their behavior in response, such as moving around less [36].

Bumblebee Gobies are carnivores and can be picky eaters. You should provide protein-rich food like tubifex, bloodworms, or daphnia.


31. American Flagfish

Scientific Name: Jordanella floridae. Family: Cyprinodontidae. Image source: “Florida Flagfish (Jordanella Floridae)” by CheepShot is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 2.5 inches
  • Temperament: Semi-aggressive
  • Min. Tank Size: 10 gallons
  • Water Temperature: 66-72° F

The American Flagfish is a pretty fish that is known for keeping your aquarium algae-free!

They prefer a well-planted tank, as they come from ponds, creeks, and small rivers with similar conditions. The male displays striking color which is likened to the American Flag [37].

These fish can be aggressive at times but will do well in a community tank. You can keep them with guppies, danios, barbs, or tetras.

They are omnivores and algae eaters. If there is not enough algae in your tank you should provide them algae wafers or tablets. They also need meat so give them brine shrimp, tubifex, and other freeze-dried or frozen food.


32. Blue Lyretail Killifish

Scientific Name: Fundulopanchax gardneri. Family: Cyprinodontidae.
  • Care Level: Easy
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 20 gallons
  • Water Temperature: 73-79° F

The Blue Lyretail is a striking and cool freshwater fish found in Nigeria and Cameroon. It lives in swamps, pools, and streams in savannah and rainforest areas [38].

Although they prefer a well-planted and slightly acidic tank, they can adapt to a range of water conditions.

They are shoaling fish and will become stressed if kept alone. So you should keep at least six of them. The Blue Lyretail is peaceful and you could house with danios, tetras, or rainbow fish.

As carnivores, you can feed them freeze-dried and live foods including brine shrimp, tubifex, and white worms.


33. Egger’s Killifish

Scientific Name: Nothobranchius eggersi. Family: Nothobranchiidae.
  • Care Level: Easy
  • Max. Size: 2 inches
  • Temperament: Peaceful
  • Min. Tank Size: 20 gallons
  • Water Temperature: 73-77° F

The Egger’s Killifish is a very cool fish that you are unlikely to find in every aquatics shop. But you can still find them if you do some digging.

Egger’s Killifish are found in pools and marshes around coastal Tanzania. They prefer soft, slightly acidic water [39].

You should keep them in a group of around six but make sure they are mainly female. Two or more males can sometimes be aggressive towards each other.

This killifish makes a good community fish and you can keep them with those such as danios or tetras.

Try to feed them live food where possible, but they will eat frozen or dried meaty foods too.


34. Tiger Hillstream Loach

Scientific Name: Sewellia lineolata. Family: Balitoridae. Image source: “Gold Ring Butterfly Loach” by Cylindric is licensed under CC BY-SA 2.0
  • Care Level: Intermediate
  • Max. Size: 3 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 68-75° F

One of our team used to keep these loaches and I think they are really cool freshwater fish. 

They are also sometimes called the Chinese Hillstream or Reticulated Hillstream loach. Another name is the Gold Ring Butterfly Loach.

They originate in fast-flowing streams in Asia and have adapted to cope with this [40]. Their wide fins which look like the skirt of a racing car definitely make them a cool fish! 

As they are bottom dwellers, you should use sand or fine gravel as a substrate. Do also keep your water parameters in check as they need very clean water.

These loaches are omnivores and will feed on any algae in your tank. You can feed them fish flakes or pellets, along with live or frozen foods such as brine shrimp.


35. Kuhli Loach

Scientific Name: Pangio kuhlii. Family: Cobitidae. Image source: Robert Mollik via Wikimedia Commons is licensed under CC BY-SA 3.0
  • Care Level: Intermediate
  • Max. Size: 4.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 50 gallons
  • Water Temperature: 79-86° F

Although this loach is quite commonly kept by aquarists it is an unusual and very cool fish.

The Kuhli Loach is found in areas including Java, Sumatra, and Malaysia. It lives in hill streams and lowland canals [41].

They are peaceful fish and should be kept in a group of at least three. The Kuhli Loach is also good for a community tank. You can keep them with other non-aggressive fish. Examples include danios, rasboras, cory catfish, or tetras.

They are carnivores so make sure you provide foods such as tubifex or bloodworms. You can also provide them with pellets as part of their diet. As bottom feeders, they will spend much of their time scavenging for food too.


36. Gold Spot Pleco

Scientific Name: Pterygoplichthys joselimaianus. Family: Loricariidae. Image source: “Marbled Pleco” by Steven’s Transport Photos is licensed under CC BY 2.0
  • Care Level: Intermediate
  • Max. Size: 12 inches
  • Temperament: Peaceful
  • Min. Tank Size: 60 gallons
  • Water Temperature: 74-79° F

The Gold Spot is a unique and unusual fish sometimes called the Marbled Pleco.

Bear in mind these fish are quite big so you’ll need a large tank. They generally grow to around nine inches but can get to twelve. In the wild, they have been measured up to 15 inches! [42].

Despite its size, this is a peaceful catfish and will do well in a community tank. You can house with a range of fish. Just avoid other similar size plecos as it can be territorial towards them.

They are herbivorous and will eat any algae in your tank. You should supplement with algae wafers as well as pelleted foods. Offer fresh vegetables too such as romaine lettuce.


37. Albino Bristlenose Pleco

Scientific Name: Ancistrus sp. Family: Loricariidae.
  • Care Level: Easy
  • Max. Size: 5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 69-79° F

The Albino Bristlenose Pleco is a gorgeous catfish with vivid color. 

You will find them in a range of subtlety different shades of white or yellow. The Albino Gold Ancistrus variety has this wonderful deep yellow skin.

They are a good community fish and don’t grow too large. You can house them with other peaceful community fish such as tetras or danios. But again avoid any similar-sized plecos.

This pleco is another herbivore that will help keep any algae in your tank under control. Supplement with algae-based foods to help maintain their color [43]. Again you can add other fresh vegetables such as zucchini to their diet.


38. Sterba’s Cory

Scientific Name: Corydoras sterbai. Family: Callichthyidae. Image source: “100215 001” by bob_jenkins is licensed under CC BY 2.0
  • Care Level: Easy
  • Max. Size: 2.5 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 70-77° F

Sterba’s Cory is a popular catfish kept by many aquarists often because of its great nature. It’s also very hardy and easy to keep.

You should set up your tank with plants and driftwood but leave plenty of swimming space. Use a fine substrate so they can scavenge through it without damaging their mouths.

Sterba’s Cory is a shoaling catfish and you should look to keep them in groups of five or more. 

If you are transporting them be aware that too many in a confined space can put them under a lot of stress. Some Corydoras can release a toxin into the water when they feel in danger [44]. It’s much better to only transport a couple at once in a larger container.

Sterba’s Cory are omnivores. You can provide them with tubifex, mosquito larvae, algae flakes, and pelleted foods.


39. Royal Whiptail Catfish

Scientific Name: Sturisoma panamense. Family: Loricariidae.
  • Care Level: Intermediate
  • Max. Size: 6 inches
  • Temperament: Peaceful
  • Min. Tank Size: 30 gallons
  • Water Temperature: 73-79° F

Also known as the Royal Farlowella or Royal Twig Catfish, this is a really cool fish to have in your tank. 

These catfish are found in freshwater habitats of South America, including floodplain lakes [45]. 

You do need to provide a reasonably sized tank for these fish with lots of hiding places. They are mainly nocturnal and so often hide during the day. 

They are peaceful community fish. You can keep them with guppies, tetras, rasboras, swordtails, and some other plecos.

This fish is an omnivore and another great algae eater. You can offer them flakes, pelleted foods, algae wafers, and fresh vegetables like spinach or zucchini. Meaty foods such as bloodworms can also be given.


40. Dwarf Puffer Fish

Scientific Name: Carinotetraodon travancoricus. Family: Tetraodontidae.
  • Care Level: Intermediate
  • Max. Size: 1 inch
  • Temperament: Semi-aggressive
  • Min. Tank Size: 5 gallons
  • Water Temperature: 72-82° F

Sometimes known as the Bumblebee, Malabar, or Indian Dwarf Puffer, this is a small fish that is undeniably striking!

You should keep these fish in a smaller, well-planted tank. Try to limit the water flow as they are not strong swimmers. 

The best plants for these fish are of the Cabomba variety. These are readily available in aquatic stores. They include Green Cabomba, Fanwort, and Carolina Fanwort.

In fact, studies have shown that keeping Cabomba plants with these fish can help reduce mortality [46].

You should keep these fish in groups of at least five, with one male for every two females. It’s better to keep these in a single species tank as they can be aggressive and nip the fins of other fish. Large fish may also see them as prey due to their slow speed and tiny size.


41. Black Ghost Knifefish

Scientific Name: Apteronotus albifrons. Family: Apteronotidae.
  • Care Level: Intermediate
  • Max. Size: 1 foot 6 inches
  • Temperament: Semi-aggressive
  • Min. Tank Size: 150 gallons
  • Water Temperature: 73-80° F

The Black Ghost Knifefish rounds off our list and is an elegant and cool freshwater fish. They are weakly electric and use this to communicate and locate food [47]. 

Be aware this is a big fish as it can grow up to a foot and a half counting its long tail. So you will need a large tank. They are also quite timid so you should provide them with plenty of hiding places and plant cover.

The Black Ghost Knifefish is a solitary fish and can become aggressive if kept with similar species. But you can keep them with large peaceful cichlids including discus and even some angelfish.

This fish is carnivorous and will eat live as well as frozen food. Bloodworms, tubifex, brine shrimp, and blackworms are all good options.


What To Do Next?

I hope this list of our favorite cool freshwater fish has given you some great ideas for your own aquarium. 

Hopefully, you can see that freshwater fish can be just as beautiful and unusual as marine species.

If you need help finding some of the fish featured here, check out our list of the best online fish stores.

Or if you have a particular interest in some of the fish featured you can check out our guide to the best goldfish care or the best care for betta fish.

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AUTHOR
Andy Birks
Andy is the owner of Simply Aquarium and manages the team of experienced writers on the site. He loves helping fellow aquarists and introducing new people to the hobby!

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