10 Black Freshwater Fish Perfect for Your Aquarium

Written by Cindy Rasmussen
Updated: April 17, 2023
© iStock.com/Mirko_Rosenau
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An infographic of Black Freshwater Fish for Your Aquarium
Fascinating black fish can take your aquarium to the next level!

Some of the most popular types of aquarium fish are colorful, like a classic orange goldfish or bright blue betta. But some fascinating black fish can take your aquarium to the next level. Read on to discover 10 black freshwater fish perfect for your aquarium!

1. Black Moor Goldfish

Black moor goldfish, Carassius auratus, in front of white background.
Black moor goldfish turn darker as they age; some get a lovely charcoal black.

©Eric Isselee/Shutterstock.com

Let’s start with the classic goldfish; instead of an orange color, the black moor goldfish is black. Do they have enormous bulging eyes? Yes! Does it make them look super cool? Yes! Black moor goldfish are sometimes called dragon eye fish due to their cartoon-like eyeballs. Their bodies are somewhat egg-shaped, and they have beautiful flowing fins. As they age, they turn darker, some get a lovely charcoal black. As adults, they can get to be 6-8 inches long.

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Black moor goldfish are selectively bred to achieve their characteristics. The fish species that breed them are the fringe tail fancy goldfish and the red telescope (another goldfish species). They are easy to care for and are peaceful fish, be sure to give them some places to hide, like tall aquarium plants or a fun decorative castle so you can watch the dragon eye storm the castle.

2. Black Lace Angelfish

The diamond-shaped black lace angelfish has lace-like flowing dorsal, anal, and tail fins. They also have two long pelvic fins that dangle below them when they swim. As adults, they can get to be 6 inches long and 8 inches tall, so you will want to be sure you have a big enough tank. Also, consider that black lace angelfish are schooling fish, so you will need a tank that is at least 30 gallons to house a small school. Black lace angelfish are a peaceful species that gets along well with various tank mates.

3. Black Moscow Guppies

Guppy male moscow
Black Moscow guppy males have a sizeable fan-like tail and a narrow body.

©Marrabbio2 | CC BY-SA – License

You can’t go wrong with a school of black Moscow guppies. The males of this breed have a sizeable fan-like tail and a narrow body that varies from all-black to silvery at the head and black at the back. Females are more silver to bronze in color, with their back half being grayer. Black Moscow guppies can get 2-2.5 inches and need a tank of at least five gallons. A stunning display is a tank lined with Java moss and Java fern with a school of black Moscow guppies and purple Moscow guppies.

4. Black Betta

There are quite a few varieties of black betta fish. Betta, generally known for their delicate long, fan-like flowing fins. They can be brightly colored, from vibrant yellows to electric blue and mixed colors, especially on their tails. Some of the most common black varieties include the black melano, lace, and orchid betta. Black melano bettas are dark black; some look black-blue, with black wispy fins and tails. Black lace betta are a little lighter in color and have a lace-like pattern on their fins. The black orchid variety have a standout color combination of black bodies with iridescent blue streaking on their tails and fins.

The body of the betta fish can get 2-3 inches, but the fanning display of wild fins can extend much further. One thing to note is that betta fish are pretty territorial, so it is key not to put two males in the same aquarium. Two fish species that make good tank mates for betta are Cory catfish and Harlequin rasbora. Speaking of black fish, the Harlequin rasbora has an attractive black lamb chop-shaped marking on its back. It would look quite lovely in a tank with your black betta.

5. Black Molly Fish

Molly (Poecilia sphenops) - black molly fish
Black sailfin mollies have a long sail-like dorsal fin that is quite stunning.


Black mollies are one of the first fish you may think of when it comes to black freshwater fish for your aquarium. They are minnow-shaped fish that are all black in color. Black sailfin mollies have a long sail-like dorsal fin that is quite stunning. Shortfin mollies, as their name indicates, have a shorter dorsal fin. Black molly fish can be around 3.5-6 inches and need a tank that is more than 20 gallons. To keep the peace, you must be careful about the male/female ratio. The best combination is one male with three females, giving the male a variety of breeding partners. Be sure to keep your aquarium in stable water conditions, some hobbyists even recommend adding some salt to make it somewhat brackish. This will ensure the healthiest home for your black mollies.

6. Black Neon Tetra

The black neon tetra isn’t quite as colorful as the neon tetra, but it’s almost as famous.


Compared to black mollies, black neon tetra are not universally all black, but their varied color makes them an attractive addition to your aquarium. These metallic-shaded fish are only about the size of a paper clip at a little over an inch. A school of 8-10 is ideal to give them plenty of tank mates. You can watch the whole glimmering school swim together. Their background color varies from silver to golden, and they have a white horizontal stripe with a black horizontal stripe right under it along the length of their bodies. There is a pop of color with these fish as their eyes are red. If you are at a pet shop and see a large tank filled with a hundred of these little guys all swimming in sync, it is quite a sight!

7. Red Tail Black Shark

A black rainbow shark with a red tail eats from the bottom of the aquarium
Red-tailed black shark (Epalzeorhynchos bicolor; Labeo bicolor)


Another fish with contrasting red and black is the red-tail black shark. Red-tail black sharks are not sharks. They get their name from their shark-like shape and attitude. They are freshwater fish in the Cyprinidae family from Thailand’s lakes, rivers, and streams. Sometimes they are referred to as red-tail shark minnows, with a minnow-like shape and an all-black body with a bright red tail. They are somewhat aggressive and chase or bully other fish entering their territory. It is either best to house them in their tank or have a large tank with other fish that keep to themselves.

Compared to real sharks, these are nowhere near the size of a shark. Bull sharks, for example, can get to be 8 feet long. Red-tail black sharks top out at 6 inches! Still a fascinating, feisty fish for your freshwater aquarium!

8. Black Skirt Tetra

The black skirt tetra gets its name from its black, skirt-like fin.

©iStock.com/Juan Carlos Juarez Jaramillo

The black skirt tetra is a mix of silver and black in a fun tetragon shape. They are in the Characidae family, along with fish like red eye, neon, and cardinal tetras. Their background color is silver, and they have two vertical black stripes on their side. Their dorsal and anal fins are black in color, but their tail fin is clear (opaque). As adults, they get to be 2.5-3 inches, which means they don’t need a ton of space, but a 15-gallon tank or more is recommended. Compared to the red-tail black shark, these fish are chill. They get along well with other tank mates and are schooling fish, so they get at least 6-8.

9. Duboisi Cichlid

Another fish with attitude is the Duboisi cichlid or sometimes called the white-spotted cichlid. They are an African Cichlid found only in Lake Tanganyika between Tanzania and the Democratic Republic of the Congo. Duboisi cichlid are plump-looking black fish covered in small white spots, but as they age, the spots fade. Although they have attitude and can be aggressive, they don’t get more than 5 inches long.

You need to be very intentional about how many males and females you put in one tank. Ideally, you would want one male with 5-6 females. These are great species-specific tank fish; the ideal setup would be a 50-gallon tank.

10. Kuhli Loach

Kuhli loach
Kuhli loach have a separate dorsal and caudal fin.


There have been some unique-looking fish on our list, but wait until you see the Kuhli loach. You will first think, “That’s an eel — not a fish!” If you look closer, you will notice two small pectoral fins that eels don’t have. Another difference is that eels have one long dorsal fin fused with their caudal (tail) fin. Kuhli loach have a separate dorsal and caudal fin.

They are not entirely black but have 10-15 black stripes along their back, and their base color is tan to pinkish. There is a black Kuhli loach that is universal in color, but they are darker brown than black. Kuhli loach have four barbels sticking out from the front of their head that they use as sensors. When Kuhli loach get threatened, they have a pair of spikes that jut out below their eye, used as a defense mechanism. Are you starting to understand how unique these fish are?

They only get 3-4 inches long in captivity, a little longer in the wild. They are bottom dwellers, which means they are good tank mates with fish that spend time in the middle or near the top of the tank, like tetras and danios. Kuhli loach are not schooling fish, but you can add 4-5 to spice up the bottom of your tank.  

Summary of the 10 Black Freshwater Fish Perfect for Your Aquarium

You can have a variety of fish in your home aquarium, but these black fish will add some pizzazz and fascination to your tank:

RankBlack Freshwater Fish
1Black Moor Goldfish
2Black Lace Angelfish
3Black Moscow Guppies
4Black Betta
5Black Molly Fish
6Black Neon Tetra
7Red Tail Black Shark
8Black Skirt Tetra
9Duboisi Cichlid
10Kuhli Loach

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The Featured Image

The black neon tetra isn't quite as colorful as the neon tetra, but it's almost as popular.
© iStock.com/Mirko_Rosenau

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About the Author

I'm a Wildlife Conservation Author and Journalist, raising awareness about conservation by teaching others about the amazing animals we share the planet with. I graduated from the University of Minnesota-Morris with a degree in Elementary Education and I am a former teacher. When I am not writing I love going to my kids' soccer games, watching movies, taking on DIY projects and running with our giant Labradoodle "Tango".

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