10 Black Freshwater Aquarium Fish

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As a novice fish keeper, you might be looking to get your hands on the most handsome fish species there are. It’s common for people to look for specialized fish colors and patterns, allowing them to create a personalized aquatic environment. Some prefer white fish, others look for red variants, while others seek black specimens to counter-balance the more vivid colors.

Today, we will discuss the latter and focus on black tank fish, which will provide your aquarium with a unique vibe. There’s nothing as vibrant as a black fish floating in a green or blue environment in an energetic shoal or school.

Here are 10 black freshwater fish that you might want to consider for your tank:

1. Black Molly Fish

Mollies are peaceful and friendly shoaling fish that can thrive in both single-species and community tanks. They make for perfect fish options for novice aquarists since they don’t require any specialized care beyond the basics. Generally speaking, mollies are rather diverse in terms of coloring and color patterns.

It’s unusual to see them only displaying one color. It’s even more unusual to see them covered in black. That is because black mollies are typically the result of melanism, which is a genetic deformation resulting in an excess of black pigment.

The condition doesn’t cause any health problems, as far as researchers know. On the contrary, it can prove beneficial in the wild since it provides improved camouflaging abilities. That being said, black mollies don’t require any special treatment compared to the rest, and they are not always completely black.

Some variations will display yellow stripes on their dorsal fins, while others can showcase silvery nuances on their sides.

2. Black Guppy Fish

Guppies are the number 1 tank fish today thanks to their astounding color and pattern variety, friendly and easy-going temperament, and amazing adaptability. Guppies are also very easy to maintain since they don’t need much to thrive.

You can find the millionfish in a multitude of color variations, including black. Just as with any other color type, black guppies can display either pure colors or mutt versions, mixed with other nuances. Full black guppies do exist, but you also have half black versions, the other half being silver or white, or light black with blue shades.

If I were to recommend a species of black fish, it would be the guppies, even if simply for their variations in patterns and tail shape. As the most popular aquarium fish in the world, guppies have been the subject of selective breeding more than any other species.

This means you can find different specimens in terms of black patterns and tail shape and size for a plus of variety and uniqueness.

3. Black Goldfish

The goldfish is always a good addition to your fish tank, especially if you’re looking for low-energy species that don’t zoom through their environment constantly. Interestingly, the black goldfish is that it is a species in and of itself. It’s called the telescope fish due to their protruding eyes, appearing ready to pop out of their heads.

The black version is called a Moor, leading to the black goldfish being most often referred to as the Blackmoor or Black Moor fish. Or even simply Moor.

These fish are similar to regular goldfish with only slight physical differences, like a bulkier body with a larger abdomen, telescopic eyes, and dedicated colors. The last part refers to the aspect of telescopic goldfish retaining their native colors throughout their lives, unlike the regular goldfish species.

Goldfish will often change their coloring based on a variety of factors, including genetics, environmental lighting, diet, water conditions, etc. Telescopic fish will retain their color throughout their lives, only experiencing changes in intensity.

This means that Black Moors will start of light as juveniles and get darker with age. This is great news seeing how goldfish can live up to 25 years, Black Moors included.

Oh yea, you also have the Panda Moor version with pink-white bodies and black fins and eyes. If you like the telescopic fish for its unusual appearance but are not fond of the black version, don’t worry. The telescopic fish displays quite a variety of colors, including red, yellow, orange, and even white.

4. Pleco Fish

Plecos are popular freshwater fish, thanks to their size, coloring, and friendly demeanor. They don’t mind the company of other fish, making them a fitting choice for community tanks, so long as you can accommodate them. After all, plecos can grow up to 12 inches depending on the species, although you can find smaller ones too.

They demand at least 20 gallons of water for smaller species and more than 70 gallons for larger ones. One thing to know about plecos is that their coloring is almost always pattern-based. They either appear spotted or display tiger or cheetah-like patterns, no matter the color they’re presenting, including black.

Just be careful if you’re considering getting a pleco for your community tank. They are notorious bottom-dwellers that love to unearth and eat plants, provided they are strong enough to do so. So, you might want to settle for a smaller species of pleco for your community aquarium.

5. Black Angelfish

Angelfish are among the most popular Cichlids on the market. Their boomerang-like bodies look amazing in larger, well-lit community tanks. It’s easy to find pure-black specimens with little-to-no color variations, but you can also find slightly altered versions. Some angelfish are black but with golden or blue undertones that are only visible in specific lighting conditions.

Other angelfish have black or red eyes or black bodies and black-gold fins. But, for the most part, black angelfish will display little color variation.

These Cichlids are mostly peaceful towards other species, so long as they are not small enough to rank as food. However, male angelfish may become aggressive towards other males of the same species over territory, food, females, or out of basic needs for dominance.

If you plan on keeping angelfish with other species, make sure you provide these Cichlids with enough space to minimize potentially aggressive interactions.

This is much more important if you plan to have several angelfish males in the same habitat.

6. Black Skirt Tetra

Black Skirt tetras are a different species of tetras that you may not be familiarized with. They don’t look like tetras, to begin with. Unlike the common tetra’s slim, torpedo-shaped body, the black one is wider and larger. Black tetras have a wider body at the nape and thorax, narrowing the tail. The fish’s anal fin is what fuels this species’ unique look, aside from its coloring.

The anal fin is wide and long, covering the entire portion between the tail and half of the abdomen, right where the ventral fins begin. This provides the black tetra with an asymmetrical look that you can’t get with regular tetras.

Color-wise, this species is not exactly black. Skirt tetras have more of a translucent body that’s rather light in coloring. The front portion of the body, which includes the thorax and head, is silver or gray, while the rear half becomes intense black. All black tetras showcase 2 vertical black stripes on their thorax, the one closer to the eyes being the shorter.

Black tetras are similar to common tetras in terms of care needs, behavior, and overall personality. Just remember that they have an innate predisposition towards nipping at large-finned fish. Other than that, they show little signs of aggression and do best in groups of at least 5 individuals.

Black tetras will make for fine additions to pretty much any community tank.

7. Black Betta Fish

Bettas are known for 2 major characteristics: their aggressive territorial behavior and their elegant, veil-like fins, reminding of a bride. I would go so far as to pronounce betta fish are the most stylish and elegant species you can get. You only need to look at the amazing color and pattern variation in the black category to see what I mean.

Some worthy mentions include:

  • Black melano – This is the blackest black betta you can find, displaying high concentrations of black across the entire body. The color is the result of a mutant gene which, interestingly enough, a lot of bettas can carry, including multicolored ones. The black variations will only appear if both parents have had the mutant gene. If only one parent has it, the result is a multicolored fish.
  • Black Devil betta – This one is a banger; there’s no other way to put it. The black devil betta displays 2 dominant colors: black and red. In most cases, black devils only display patches of intense red on their backs, head, and thorax, while everything else is black. The problem is that producing these types of bettas in captivity is rather a game of luck. It’s not obligatory for 2 black devils to spawn black devils of their own. Which makes this type that much more valuable.
  • Black Orchid betta – This is another black variation worth mentioning thanks to its astounding esthetics and unique look. Black orchids are typically black with steel-blue stripes embedded in their fins. These provide them a similar appearance to either an orchid or a butterfly. Either way, it’s breathtaking to see one swimming in your tank.
  • Copper-Black betta – This one is among the most popular betta types in the aquarium world and for good reasons. The 2 dominant colors are black and copper, but each specimen will diverge slightly from the norm. Some may include shades of purple, white, or yellow and display wildly varied patterns. The copper-black betta can showcase clean color distinctions with black bodies and copper fins or mixed colors for a less uniform appearance.

If you’re a fan of black fish, the betta will most likely scratch that itch better than any other species.

8. Red Tail Shark

If you’ve never heard of the red tail shark, this is the best moment for it. This is a Thailand-sourced endangered species that has gained a lot of popularity over the past several years. Part of it is thanks to its unique appearance. The red tail shark can reach sizes of up to 6 inches in captivity and displays an elongated and slim body, usually black, blue, or gray.

You may even find them in transparent-white variations.

The aspect that makes this species so appealing is its red tail. This shark will always come in 2 colors, with one of them being the tail’s red which is present in all variations. This omnivorous species can live up to 8 years and require around 55 gallons of water per specimen.

They are quite territorial and don’t appreciate other fish species in their proximity, which may not qualify them for rich and active community tanks.

9. Black Ghost Knifefish

If you’re tired of all the common species and would like something more unique as a tank pet, the ghost knifefish is the one. This unique-looking species has taken off recently thanks to its otherworldly look. You may not even qualify it as a fish at first glance.

The ghost knifefish is mostly black, with only a white stripe across its tail. Some even have a longitudinal white stripe across their backs, traversing their bodies head to tail. The thing that makes this species unique is that it lacks dorsal and tail fins. This fish is smooth like an eel, and it even resembles one in the head area.

This fish swims thanks to its ventral and anal fins, which are actually blended together in one giant fin traversing the entire body. It looks similar to a stingray’s ‘wings’ except not as prominent and facing downwards, not laterally. Think of a snail swimming, and you’ll get the picture.

The ghost knifefish can reach up to 18-20 inches in size and requires a 100-gallon tank to remain healthy and thrive in the long run. On the fun side, this species can live up to 15 years with adequate care and optimal living conditions.

10. Black Pacu Fish

We end this list with something heavy. The pacu fish is also known as Tambaqui, black pacu, gamitana, or cachama, and it comes from South America primarily. This is a freshwater fish whose juveniles resemble piranhas, for lack of a better description. In their full adult form, pacus are bulky with very small fins, compared to their massive bodies and little color variation.

You can find them in gradients of blue, purple, or black, but nothing else really. If you plan on getting a black pacu, you might need to invest in a slightly larger tank. An adult pacu can grow up to 3.6 feet in length and weigh up to 100 lb. But don’t worry, this is the largest version.

You also have smaller versions, measuring only 2.3 feet and around 50 lb. Yea, this species is like that.


Black fish don’t have to be bland and boring. Depending on their species, they can often be even more exhilarating than their multicolored versions.

Use this list as a guide, choose your favorite black specimens, and thank me later.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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