The 10 most popular aquarium fish

There are an incredible number of aquarium fish. But which are the most beautiful species and which fish can beginners keep? 

This article introduces you to the 10 most popular aquarium fish and will briefly explain their requirements, behavior and special features.

1. Guppy (Poecilia reticulata)

popular fish

Guppies are best known for their magnificent tail fin. Due to their robust nature, they are popular aquarium fish with beginners and are ideal for small and medium-sized community tanks. The origin of the guppies is freshwater waters of all kinds in Central America and Brazil.

The aquarium should be at least 60cm wide and have a capacity of 54 liters. Guppies live in groups of 5 or more and can be found in all parts of the aquarium. It is important that there is dense vegetation and that the current in the pool is not too strong. Because guppies are viviparous fish, it is easy for even beginners to breed offspring.

Guppies can grow up to 5cm. The males are not quite as big as the females, but are more beautiful and colorful. There are many different cultivated forms of the guppy, which differ in color and length and shape of the caudal fin.

Difficulty: easy

  • pH value: 6 – 8.5
  • Total hardness: less than 30 ° dGH
  • Temperature: 24-27 ° C

2. Platy (Xiphophorus maculatus )

popular fish

Just like guppies, mollys and swordtails, platies are live- bearing fish. They are also quite undemanding and can be kept very well by beginners. Depending on the species, platies are colored very differently. The most widespread cultivated form is the coral platy.

Platys are available in almost every imaginable color, but yellow, orange and red tones are particularly common. Its high back and its scales that shimmer in the light are characteristic. Platys are popular because of their sociable yet lively manner.

The aquarium should be at least 60cm wide and have a capacity of 54 liters for species-appropriate keeping. Platys should be kept in groups of at least 5 animals and can be socialized with many other species. Platys are also viviparous fish, which is why even beginners can breed offspring.

The platy comes from waters in Central America and can grow up to 6 cm. In addition to the usual dry food, platies also feed on algae that grow on roots and stones.


  • pH value: 7.5 – 8.5
  • Total hardness: 5 – 25 ° dGH
  • Temperature: 18 – 28 ° C

3. Mollys (Poecilia sphenops)

popular fish

Mollys, guppy, swordtail and platy belong to the viviparous toothcarp family and are therefore quite closely related. All three types are thus similar in some ways. The Black Molly in particular is popular with many aquarists, which makes it one of the most famous ornamental fish of all.

In contrast to Guppy and Co., the Mollys is a bit more demanding in keeping. Soft water with a total hardness below 12 ° dGH is unsuitable for keeping. In addition, Mollys need a water temperature of at least 25 ° C and some retreat options.

Female mollys can grow up to 10 cm, while males only about 6 cm. The aquarium should have a width of at least 80 cm and a volume of 112 liters for species-appropriate keeping. Mollys should also be kept in groups of at least 5 animals.

There should always be more females than males in the tank. Mollys are viviparous and will therefore give you offspring quickly. Some offspring of the Black Mollys turn gray with black spots and not entirely black.


  • pH value: 6 – 8
  • Total hardness:  12 – 30 ° dGH
  • Temperature:  25 – 30 ° C

4. Discus (Symphysodon)

popular fish

The discus from Amazonia is one of the most beautiful, expensive and demanding freshwater fish. Discus fish differ from real discus in that they do not have horizontal stripes. Discus fish are impressive animals that are completely unsuitable for beginners.

The discus owes its name to its disc-like shape. Keeping them requires very well filtered and soft water, as well as tropical woods and large-leaved plants. In addition to the impressive patterns and colors, the distinctive social and mating behavior of these animals also inspires.

Discus fish can grow up to 15 cm and should be kept in groups of 5 or more or as pairs. A pool for discus fish should have a minimum width of 120 cm and a volume of 300 liters. Larger tanks with 400 liters and more are better. The breeding of discus fish is very difficult and only succeeds under suitable conditions.

So that no diseases develop, the discus must be fed very variedly. In addition to dry food, you also have to feed live and frozen food such as mosquito larvae.

Even if the discus is extremely sensitive and demanding, the attitude is always worthwhile. For me, the discus fish is the most beautiful and interesting ornamental fish of all, alongside the related angelfish.

Difficulty:  very difficult

  • pH value: 5 – 7
  • Total hardness:  12 – 30 ° dGH
  • Temperature:  26 – 32 ° C

5. Neon tetra (Paracheirodon innesi)

popular fish
Neon tetra

A native of the Amazon schooling fish is one of the most popular aquarium fish. Thanks to the slow swimming movements, a swarm of neon brings calm to the aquarium. There is the blue neon, the red neon and the neon salmer. Unlike the red neon and the neon salmer, the blue neon has no red stripe under the blue stripe.

The red neon has a solid red stripe, whereas the neon tetra has only half a red stripe. Neon fish are perfect as additional stock in larger community pools. Because of its bright colors, which shimmer in the light, the neon fish is represented in many aquariums.

In contrast to the blue and red neon, the neon tetra is a little less demanding, which makes it most interesting for beginners.

Neons should be kept in a pool with a minimum width of 60 cm and a volume of 54 liters. Since neon fish are schooling fish, they must be kept in groups of at least 10 animals, but they only develop their true beauty in schools of 20 animals and more. Breeding offspring proves difficult, and is next to impossible in community tanks.

Often times, neons are referred to as the optimal beginner fish. When it comes to keeping the water, there are still a few things to consider. Neon fish feel comfortable in acidic, soft and rather cool water. If the water values are not correct, illnesses are favored and the fun is quickly over.


  • pH value: 5 – 7
  • Total hardness:  less than 10 ° dGH
  • Temperature: 20 – 28 ° C

6. Angelfish (Pterophyllum scalare)

popular fish

Just like the discus, the angelfish belongs to the cichlid family. The scalar impresses with its impressive shape and majestic appearance. Depending on the species, angelfish can reach a height of over 40 cm, which makes keeping them in tanks with less than 240 liters impossible.

Angelfish are predatory fish, which is why they occasionally allow themselves an additional meal in the form of smaller fish like the neon.

The socialization of angelfish with small fish depends on the individual behavior of the angelfish. In many cases the socialization goes by hand without any problems, in others angelfish regularly grab small fish on. It is safest to socialize angelfish with several medium-sized fish.

Angelfish reach a size of up to 15 cm and a height of up to 40 cm (including belly threads and fins). In order to guarantee sufficient swimming space, a suitable pool should be at least 120 cm wide and 60 cm high. Scalars can be kept in groups or in pairs.

So there should always be at least 2 scalars in the tank. The breeding of offspring is usually only possible because the eggs are usually eaten.

Compared to discus fish, the scalar is a little easier to keep. However, angelfish are only suitable as a stocking for large-volume aquariums with 200 liters and more. Angelfish should also occasionally feed live and frozen food.


  • pH value: 5 – 7.5
  • Total hardness: less than 15 ° dGH
  • Temperature:  25 – 30 ° C

7. Siamese fighting fish (Betta splendens)

popular fish
Siamese fighting fish

The Siamese fighting fish has a good reason for its name. The colorful fish is by nature a loner who is very territorial. Both conspecifics and other fish are not tolerated in their own territory.

Fighting occurs among male fighting fish, some of which are fatal. Fighting fish females are harassed and hunted by the males for mating purposes.

Due to the strong territorial formation and aggressiveness (especially in cultivated forms), it is particularly important for fighting fish that the aquarium is of sufficient size.

In aquariums with a width of less than 100 cm, it is recommended to keep them individually due to the formation of the territory. Siamese fighting fish is characterized by their very long, sometimes veil-like fins and their strong colors. There are now many cultivated fish in many colors and fin shapes.

The fish from Thai waters can grow up to 7 cm. The male fighting fish have longer fins and are more vividly colored. For species-appropriate housing, the tank should hold at least 25 liters and be densely planted.

For most aquariums I recommend keeping the fighting fish individually, as this avoids the often fatal fights. Siamese fighting fish can by no means be socialized with all fish.

The fish must not be too small, as they would otherwise be seen as food, nor have their fins too long (e.g. the guppy), as they can be mistaken for conspecifics.

Difficulty: normal

  • pH value: 6 – 8
  • Total hardness:  12 – 30 ° dGH
  • Temperature:  25 – 30 ° C

8. Antenna catfish (Ancistrus spec.)

popular fish
Antenna catfish

The antenna catfish is a calm, peaceful and very robust aquarium inhabitant. He can be socialized with almost all peaceful animals. In contrast to females, males have antler-like protuberances on their foreheads.

They are also known as the “wheel cleaner” or “suckermouth catfish”.

As you probably know, catfish stay on the ground of the aquarium. Unlike most other aquarium fish, they do not feed on flake or live food, but on algae, food that has fallen to the ground and any other remains that they find on the bottom.

Antennae catfish are solitary animals that do not like to share their territory with other species. In order to keep catfish, there must be a root in the tank that they scrape off in order to obtain important fiber from it.

Adult catfish can reach sizes of up to 14 cm. The basin should therefore have a minimum width of 80 cm and a minimum volume of 112 liters. There should be hiding places in the form of dense planting and caves.

If several catfish are kept in one tank, there should be two to three females for each male. If several males are to be kept in one tank, the tank must be significantly wider than 80 cm due to the territorial behavior.

The antenna catfish is a peaceful and very robust aquarium fish, which also protects the tank from pollution due to its eating habits. Even if the catfish does not show any particularly noticeable behavior during the day, it is a very beautiful fish in my eyes that brings calm to the aquarium.

Difficulty: easy

  • pH value: 6 – 8
  • Total hardness: below 25 ° dGH
  • Temperature: 18-30 ° C

9. Swordtail (Xiphophorus hellerii)

popular fish

The swordtail is so closely related to the platy that together they can produce (sterile) offspring. Characteristic and name-giving is the sword extension formed by the caudal fin, which makes up 1/4 to 1/2 of the body size depending on the cultivated form.

The sword extension is only present in male swordtails. The fin of the female is similar to that of the platys. In my opinion, swordtails are the most interesting representatives of the viviparous toothcarps.

Especially their courtship behavior, in which the males swim stormily through the water, jump out of the water and even swim backwards, is very impressive and interesting.

The swordtail originally comes from Central America, can reach a size of up to 10 cm and should be kept in groups of 5 or more. Due to its spirited and stormy nature, an aquarium width of at least 100 cm and a solid cover are necessary so that they have enough space and cannot jump out of the pool.

Unlike most ornamental fish, the swordtail prefers slight temperature fluctuations. The breeding of offspring succeeds under very simple conditions.

If the requirements match, the swordtail can be socialized with almost all other ornamental fish. It brings movement into the pool and is also suitable for beginners.


  • pH value: 6.5 – 8.5
  • Total hardness:  10 – 30 ° dGH
  • Temperature: 22 – 28 ° C

10. Dwarf gourami (Colisa lalia)

popular fish
Dwarf Gourami

Dwarf threadfish are calm and sociable aquarium fish. The males are brightly colored, while the females are a little less conspicuous. As the name suggests, dwarf threadfish are not particularly large at just 5 cm.

This somewhat shy species needs a densely planted aquarium that offers many retreats. Dwarf threadfish can be kept well as a pair. They are relatively susceptible to various diseases and parasites, which does not make keeping them easy for beginners.

This fish, which comes from India, feels most comfortable in medium-sized aquariums with a width of 80 to 100 cm. Dwarf gourami build a nest out of foam in which they lay their eggs. The breeding of offspring is not easy, but with some precautions it is possible even in community tanks

The dwarf gourami is a beautiful and species that brings color to medium-sized aquariums. Dwarf threadfish are rather calm and withdrawn fish, but they are still nice to watch.

Difficulty: normal

  • pH value: 6 – 8
  • Total hardness:  below 15 ° dGH
  • Temperature: 24 – 30 ° C

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