If you’re a fish enthusiast who loves to keep one bright and beautiful tank at home, it is of prime importance that the fish in there are absolutely stunning to look at. Aquariums are not just entertaining; they are engaging as well. Also important is that the fish tank is not just vibrant but healthy too.
Which fish to keep in the aquarium so that it appears to be strikingly colorful and absolutely stunning?
If you’re a beginner, this question might bug you even more. However, there is no need to fret about it because this article attempts to bring to your knowledge the 20 most beautiful fishes of all times that can make your aquarium look exquisite. Knowing those personalities will help you maintain your aquarium better.
Read on to find out more. The list below is a combination of pretty fishes of various types and sizes, and it states every detail that you need to know about them before keeping them as pets.
1. Neon Tetra
Originating in south-eastern Columbia, Neon tetra is a small, 10-gallon tank fish. They could easily survive at a temperature of 68 to 79 degrees Fahrenheit and a pH 7. At maturity, their length is approximately 1.5 inches. They are, in fact, one of the smallest, brightest, beautiful fishes and yet, one of the hardiest that you could probably grace your fish tank with.
They are simply stunning to look at. It is considered that this cute little fish has a blue marking from the tip of its nose to its adipose fin, which makes it more visible.
Apart from that, it has a silvery-white belly and red stripe that runs to its tail. Can you imagine just how fancy it looks? They are good with other non-aggressive fishes. However, if kept with other tetras, they will eat each other at the first opportunity.
2. Oscar
If you’re looking for a pretty fish that is absolutely vibrant but slightly large, you could go for an Oscar. There are several varieties available, namely, Lemon, Red, Zebra, and Tiger. You could get any that you like.
Known to be the most intelligent aquarium fish, an Oscar, at maturity, can measure up to a foot long. They are known to be semi-aggressive to other fish species. They thrive when kept in a group of 5+ only if they have been introduced really early.
Oscars are known to be super aggressive to the aquarium décor as well. They are carnivorous and create a lot of waste; so naturally, they require a lot more maintenance and care. They are also one of the very rare kinds that can be handfed. They will eat from between your fingers even!
3. Mollies
If you have been looking for something small, simple, beautiful as well as peaceful, mollies could be the best choice for your fish tank. This omnivorous fish is a live-bearer. In case you are wondering what that means, it means they give birth to their young ones rather than laying eggs.
Very easy to care for and to breed, mollies are perfect for beginners. At maturity, their size is about 3 to 4 inches, and they can easily fit in a 20-gallon tank with a pH between 7.0 to 7.8.
Mollies are spectacular to look at as well. Greyish black with a yellow line running across the edge of their tail, mollies could easily fit the color scheme of your fish tank.
4. Goldfish
Needless to say, this is one of the most common and the most appreciated aquarium fishes of all time. Almost everyone who has an aquarium has it or had it. They are so simple yet, so majestic. However, it is very easy to underestimate them by just considering the little beautiful babies that are commonly sold around in the fairs or even in the markets. At maturity, a goldfish can measure anything between 10 to 12 inches.
Fit for a 20-gallon fish tank, the Goldfish comes in more varieties than we would think of, and each of them is equally splendid. You could pick any that you like. Some varieties share their patterns with that of koi fish and, thus, are perfect for the people who love koi but cannot really handle a large fish. It is simply terrific!
5. Boeseman’s Rainbowfish
This pretty fish is something absolutely unique. It is a schooling fish and the most vibrant one at that. It is so colorful that it is somewhat bound to dazzle you with its beauty. Originating in Australia and Southeast Asia, Boeseman’s Rainbowfish can measure anything between 4 to 6 inches in length at maturity.
This bicolor fish, whose color begins to show as it enters adulthood, is one of the least common fishes to be kept in a fish tank. A 55-gallon tank is well suited for this hardy fish, given that they like to live in groups of 6 or more. Peaceful in nature, this bright fish thrives well in a community tank with other non-aggressive fishes. They color the best in well-planted tanks.
6. Bettas
Also known as the Siamese Fighting Fish, Bettas are an absolute pleasure to look at. Living for up to 3 years, an adult Betta can measure up to 3 inches in length so size-wise, they are pretty manageable. Their long-flowing fins and astounding coloration give them away. As is apparent from their names, their origin was in Siam, a place in Thailand. In Bettas, the females are very slightly smaller than the males.
At a pH 6.8 to 7.4 and temperatures between 75 to 86 degrees Fahrenheit in a minimum 2-gallon tank, Bettas can thrive really well. However, they cannot be kept in a tank with other species without the use of separators. Several females can be kept together in peace.
7. Red Wagtail Platy
Originating in Central and South America, Red Wagtail Platy is listed among unique fishes that are small, hardy, and easy to maintain. In other words, it is a fish well suited for a beginner. Brilliant to look at, this fish is both peaceful and active at the same time. So it is recommended that it be kept in a tightly sealed fish tank at all times.
It is a live-bearer fish with a lifespan of approximately 4 years, and the size of an adult can be 2 inches. Its size is so small that it can be easily kept in a 10-gallon tank. The good thing about it is that it is an omnivore. It can survive easily in pH levels between 7.2 and 8.0 and temperatures between 64 and 77 degrees Fahrenheit. They have an orangish-red and black body and are extremely brilliant to look at.
8. Zebra Danios
Also commonly known as the Zebra fish, they are among the most unique fishes of all time. They are not only loyal to their breeding partner, but also they consider them to be their partner for life. It is simply amazing. As its name implies, their appearance is much like the zebra, with white and black stripes on their bodies.
If you’re wondering as to why they have made it to the list of most popular beautiful aquarium fishes, it is because they are really simple to care for and they breed quite easily. Measuring about 2 inches at maturity and with a lifespan of about 5 years, the origin of the Zebrafish is in eastern India. They are quite peaceful and are well suited for community tanks with a pH level between 6.5 and 7, and temperatures between 64 and 74 degrees Fahrenheit.
9. Pearl Gourami
In case you’re wondering what is so unique about the Pearl Gourami fish, the answer to it is that it is a Labyrinth fish, meaning, it gulps the air on the surface of the fish tank in order to breathe. What is even more unique about it is that it can actually be very ‘vocal,’ just like other labyrinth fishes. It is, in fact, one of the most beautiful of all the varieties of gourami fish that are available. They thrive well in temperatures between 77 and 82 degrees Fahrenheit and in pH levels between 5.5 and 7.5.
These Gouramis are extremely bright and brilliant to look at. With its origin in Malaysia, this fish can grow up to 4.5 inches in length at maturity and has a life expectancy of about 4 to 5 years. This peaceful omnivore is well suited for a 20-gallon tank. Brown and pearl markings cover its body and a black horizontal line runs up to its tail. It is from its appearance that the fish gets its name. This fish is well suited for a community tank.
10. Cherry Barb
Suited for a slightly heated up fish tank, a Cherry Barb fish is absolutely marvelous to look at. In fact, it is one of the best fishes with which one can begin a freshwater fish tank. These are a member of the Cyprinid family. At maturity, these fishes can grow up to 2 inches in length. Seeing that their size is rather small, it can be said that they can be very well kept in 10-gallon tanks. They are closely related to goldfish. They have a very slender red body with dark marks all along their lateral lines. It is from their appearance that they get their name.
11. Koi
For anyone who is looking for a considerably large, but peaceful by nature fish to keep in their freshwater tank, they could easily go for koi. Although their care level could range from intermediate to hard, these fish are worth your time and effort.
They are somewhat sensitive and thrive well in rather cool temperatures. However, their tanks need regular weekly maintenance. They are omnivores and would feed on almost anything. At maturity, they can grow up to 3 to 4 feet long.
12. Guppies
Underrated beauties are exactly what guppies are known to be. No matter what color combination you have in mind for your fish tank, you are bound to find a variety of guppies that can easily suit your color scheme.
Guppies can come in absolutely bold, mosaic patterns or even in the albino strains. However, it must be kept in mind that the fancier they are, the weaker they get. They are extremely small in size. At maturity, males are about 1.5-3.5 cm long, and females are about 3-6 cm.
Guppies are peaceful community fish and it is recommended that a group of 2 females and 1 male be kept in a 10-gallon tank. These are live-bearers. Native to coastal northeast South America, guppies can survive in a wide range of conditions. However, a temperature between 50 to 84 degrees Fahrenheit is considered optimal for them.
13. Clown Killifish
If you’re looking for a species that is both gorgeous and has a decent life expectancy, you could easily go for the cute Clown Killifish. They are absolutely adorable to look at.
It is a fish of fine temperament that can settle easily with other fishes in a community tank. It prefers a slightly cool temperature in the tank. They are pretty small and even at maturity, they are seldom seen to grow over the length of 1.5 inches. Their body is rather simple with brown and yellow stripes. However, their tails are a special feature. They look like big, beautiful fans.
14. Freshwater Angelfish
These are some of the most common fishes kept in a freshwater fish tank. What is more, is that they are good for beginners as well. No matter which species you go for, Zebra, Koi, or any other species, all are equally colorful and beautiful. Easy Angelfish care advantage also makes it a convenient choice for beginners. However, at maturity, they can grow up to be about a foot in length. So, they are well kept in 55-gallon tanks. Also, they love well-planted tanks for themselves.
15. Ram CichlidÂ
 One of the most peaceful and elegant fishes that you could probably keep in your fish tank is the Ram Cichlids. They are a rather quiet variety and prefer a private corner of the tank for themselves. These cute fishes seldom disturb other fishes in a community tank and can surprisingly also be kept with guppies. They are the only member of the Cichlid family that can be kept in a 10-20 gallon tank. Their maintenance, too, is easy, simple, and cost-effective. These are incredibly wonderful and breathtaking to look at.Â
16. Flowerhorn Cichlid
 These are massively aggressive fish and it is recommended that they are not kept in a community tank. They are very territorial. This fish, with a lifespan of 4 to 5 years, can grow as large as 12 to 16 inches in length at maturity. They are easy to care for; however, they are not easily available at pet stores. If kept alone, they would require a 120+ gallon tank, and if kept in a pair of 1 male and 1 female, they need a tank of 175-200 gallons to be able to live comfortably. They take a great deal of liking to their owner.Â
17. Discus Fish
 This is one of the rare varieties of round fish that were previously handpicked only at the Amazon. Now, many breeders all across the US have been successful at breeding them in several colors. No matter what the color is, they are always very bright to look at. It is better that you get them only if you have a great deal of experience in keeping fishes in tanks. The reason is not only are they expensive but also they are highly sensitive.
Discus requires pure water for their survival, which means that their tank must be very frequently cleaned. Their breeding requires absolutely perfect conditions and a lot of patience. Understandably, it would not be a very easy job for a beginner. Also, they require rich foods like a beef heart.Â
18. Arowana 
Very majestic and regal, Arowana is a fish that has been part of gallant and legendary tales where they have been known to save their owners from some near-death experiences. Well, they are only stories, but they simply add more majesty to this beautiful fish. These are extremely large in size, just like the koi. At maturity, they can grow up to 3 to 4 feet in length. Huge fish tanks are required to keep these beasts of fish.Â
19. Firefish Goby
 If you like keeping a saltwater fish tank, you just cannot skip keeping this beautiful little fish in your tank. They might as well be the most beautiful fish that you ever behold. At maturity, they grow up to a length of a maximum of 2 to 3 inches, which makes them perfect for a 10 to 20-gallon tank. They prefer dim lights. These fish have a personality of their own, and they are rather shy by nature. They do well with other fishes in the tank as long as they are not predatory.Â
20. Designer ClownfishÂ
Last but not least, on the list is undoubtedly the Designer Clownfish. Simple and beautiful to look at, these are one of the new varieties of fish that are being kept in the tanks. Again a saltwater delight, a 20-gallon tank is just fine for this fish to thrive. They are available in 50 different patterns. They can grow up to a length that is anything between an inch to 4 inches. Because of its shy nature, the Designer Clownfish, too, can thrive pretty well with other fishes in the tank.
The list is fascinating, is it not? It has such a wide array of fishes that you are bound to find some that actually suit your aquarium. Rest assured that keeping some of those in your aquarium would make it look simply mesmerizing.
