Most Beautiful Aquarium Fish: 15 Species That’ll Catch Your Breath!

There is no unanimous agreement about the most beautiful aquarium fish. However, some widely accepted favorites include threadfin butterflyfish, betta fish, clown fish, and flame angelfish. Additionally, many fish enthusiasts believe that certain species of crested angelfish and coral snakes are also stunning in their own right. Therefore, the most beautiful aquarium fish is subjective, but some definite contenders exist.

Beautiful Fish Species for Your Aquarium

1. Mandarinfish (Synchiropus splendidus)

The Mandarinfish is a bizarre creature that looks like something out of a science fiction movie. But this isn’t some alien monster – it’s a real animal found off the coast of Australia. This small fish lives in shallow waters, hiding among rocks and coral. And while it doesn’t look hazardous, there’s no denying that it’s incredibly venomous. It produces a toxin called tetrodotoxin, which gives it its name – the word “mandarin” refers to a poisonous fruit.

This poison causes paralysis and eventually death. It’s so deadly that you could easily mistake it for a jellyfish sting. Unlike jellyfish stings, however, the mandarinfish’s venom kills quickly. If you accidentally touch one, you might feel nothing for hours – or even days. You may think a sea worm or jellyfish has bitten you. But you haven’t.

2. Juvenile Emperor Angelfish (Pomacanthus imperator)

Emperor Angelfish is one of the most striking fish in the ocean. They live in warm tropical waters and feed primarily on small crustaceans. Their diet consists mainly of shrimp, crabs, mollusks, worms, and insects. As a juvenile, they look pretty different from the appearance they have as an adult. This is because they undergo dramatic changes during development, changing coloration and patterns.

Juveniles are often found near reefs, where they spend their early life stages feeding on plankton. When they mature, they move away from shallow water towards deeper habitats, where they begin to feed on smaller organisms such as zooplankton and benthic invertebrates. Emperor Angelfish reach lengths of up to fifteen inches; however, in captivity, they usually grow to about twelve inches. They are generally peaceful animals that prefer to hide in crevices and holes rather than swim freely in open areas. However, they do sometimes venture out onto the reef surface.

3. Clown Triggerfish (Balistoides conspicillum)

The striking clown triggerfish is immediately recognizable. Its lower half is dark with large white blotches, while the upper half is bright yellow with smaller black dots. This combination makes it easy to spot even a group of similar-looking fish. As juveniles, the triggerfish are usually very shy and reclusive, hiding away from sight. But once they reach maturity, their personalities come out, and they become much bolder. If kept alone, however, they should never be placed near aggressive species like lionfish.

4. Picasso Triggerfish (Rhinecanthus aculeatus)

The Picasso triggerfish is one of the most popular fish in the aquarium trade. It has a distinctive appearance, with its body divided into two equally sized parts. The upper part is bright orange and yellow, while the lower half is dark brown with black stripes running along its sides. This division makes it easy to tell apart from other triggerfishes by sight alone!

5. Clownfish (Amphiprioninae)

The Clownfish shot to fame following its appearance in Pixar’s animated film Finding Nemo. This popular aquarium fish is also known as a false clownfish or clown anemonefish because it is home to sea anemones and is native to the tropical waters of southeast Asia and Australia. They are often found living in pairs, and both sexes can reproduce.

Clownfish are very active animals, spending much of their day swimming around searching for food. They feed mainly on small crustaceans such as shrimp, crabs, and hermit crabs. If disturbed, they will swim away quickly, sometimes hiding under rocks. In captivity, clownfish are usually kept in groups of 5 – 10 individuals per tank. They enjoy lots of space to move around and hide out in caves and crevices. Clownfish are easy keepers and do well in most conditions, although they require some water movement to avoid stress.

6. Regal Blue Tang (Paracanthurus hepatus)

This species of fish originates from Australia, where it lives in tropical waters. These fish feed on small crustaceans like shrimp, crabs, and insects. Some people keep the fish in large tanks, while others prefer smaller ones. These fish are easy to care for. They require little attention. You have to make sure you provide enough food and clean water. They do not need much space either because they are not territorial. But they do enjoy having some companionship.

7. Regal Angelfish (Pygoplites diacanthus)

The regal angelfish is among the most beautiful fish species out there. But don’t let its appearance fool you; this fish packs a powerful punch. Its sharp teeth make it a formidable predator, capable of tearing apart small prey such as shrimp and crabs. A regal angelfish will eat almost anything you give it, including food pellets. Regals usually live in groups of 2 to 4 individuals. This group dynamic allows members to protect each other from predators. The group leader will swim to the surface and emit a loud rattle sound when threatened. Then the rest of the group will follow suit.

8. French Angelfish (Pomacanthus paru)

The angelfish is a popular choice among reef keepers because of its striking appearance and ease of care. These fish are peaceful and friendly towards humans, making them easy to handle. They make great pets due to their calm demeanor, and they don’t require much maintenance. They like a temperature range of 72°F – 78°F (22°C – 26°C) and a pH level of around 7.0. Their diet consists mainly of live foods such as brine shrimp and bloodworms, and they do well with frozen food items such as frozen bloodworm nuggets.

9. Flame Angelfish (Centropyge loricula)

The flame angelfish is one of the most popular reef aquarium fish. It is easy to keep and requires little maintenance. These fish are pretty peaceful and do well with others. These fish are native to tropical waters in the Pacific Ocean, including Australia, Indonesia, Malaysia, Papua New Guinea, Philippines, Solomon Islands, Taiwan, Thailand, Tonga, Vanuatu, and Vietnam. They prefer to live in pairs or small groups of up to ten individuals. This species does best in a planted aquarium with lots of plants and rocks.

10. Lionfish (Pterois)

Lionfish are native to the Indian and Pacific Oceans and are also known as the dragon, tiger, scorpion, and sea catfish. They are considered invasive because they don’t have any natural predators and eliminate native species. Instead, they reproduce quickly and can easily adapt to new environments. Most lionfish are about 2 to 16 inches long and have the most beautiful striped bodies arranged in what looks like a zebra pattern. Their feathery fins attract smaller fish and make it easier for them to catch prey.

Although they might look harmless, lionfish have venomous spikes that they use for defense. These spikes cause painful wounds to humans and even kill small animals such as crabs and shrimp.

11. Moorish Idol (Zanclus cornutus)

The Moorish idol is one of the most recognizable species of reef fish. These gorgeous creatures are usually spotted swimming around the reef, looking for food. Their bright colors make them easy to spot even though they are often hard to photograph because they move quickly. Moorish idols are very popular among divers and photographers alike and are often seen in many different types of pictures, including underwater photography, macro photography, and even commercial artwork.

12. Banggai Cardinalfish (Pterapogon kauderni)

Banggai Cardinalfish are natives of the Banggai Islands group in Indonesia. This beautiful fish is often seen swimming amongst seagrass beds and coral ledges while it rests during the day. When it is feeding, it feeds in large schools of up to 200 individuals. During the night, it feeds on smaller insects and zooplankton. In captivity, these fish require a lot of room to exercise and play. A good-sized aquarium is recommended.

13. Heckel Discus (Symphysodon discus)

This beautiful fish is often thought to be the king of the aquarium. It’s a stunning centerpiece, and not hard to see why! From the front, it looks pretty thin, but from the sides, they are a round disc-shaped fish. Usually reaching about six inches in length, the discus is very peaceful, elegant, and graceful. They are commonly referred to as the “Heckel Discus,” although many call them the “pineapple fish.”

They are native to the Amazon River basin and one of the most challenging species to keep. Their diet consists mainly of algae, though they enjoy some live food too. The Red Discus is a wide variety, and they are also called the “Amazonian Red.” Although there are several different varieties, the Red Discus is generally considered the most beautiful species.

14. Threadfin Butterflyfish (Chaetodon auriga)

The butterfly fish is one of the most popular freshwater tropical fish species in the world. They are easy to care for and maintain, making them great pets for beginners. These fish are very active and require plenty of space to swim around. A large tank is recommended to keep up with their activity levels.

15. Koi Carp (Cyprinus rubrofuscus)

One of the most well-known varieties of koi, the koi has been kept in ponds for thousands of years. There are several kinds of koi, and they come in various colors, including black, blue, golden, silver, white, and red. Keep in mind that a good environment should have a pH of about 6.8.