10 Unique Pet Fish for Your Aquarium

Aquariums can bring a sense of tranquility and beauty to any home. While many people gravitate toward common fish like goldfish or bettas, there’s a world of unique, colorful, and fascinating species that can make your aquarium stand out. Choosing the right fish for your tank depends on factors like tank size, water conditions, and the level of care you’re willing to provide. From vibrant tropical species to oddball aquatic creatures, here are some unique pet fish that will not only brighten up your aquarium but also give you a rewarding experience as an aquarium owner.

1. Discus Fish

An orange discus fish — Image Credit: H. Zell, CC BY-SA 3.0, Wikimedia Commons.

Known for their round, vibrant, and multicolored bodies, discus fish are a stunning addition to any aquarium. Native to the Amazon River, they thrive in warm, soft water conditions. However, they do require careful water quality management and a bit of experience, as they are sensitive to changes in their environment.

2. Koi Fish

Two white and one orange koi fish swimming as viewed from above — Image Credit: Bernard Spragg, Public Domain, Wikimedia Commons.

Koi are large, ornamental fish with a calm demeanor and striking color patterns, including shades of orange, red, white, and black. These fish can live for decades and are perfect for outdoor ponds. Their impressive size and tranquil movements make them both beautiful and captivating to watch.

3. Electric Blue Ram

Electric blue ram cichlid — Image Credit: BlueRam92, CC BY-SA 4.0, Wikimedia Commons.

The electric blue ram is a striking species known for its vibrant blue coloring and peaceful temperament. Native to South America, these small cichlids are perfect for freshwater aquariums with the proper water conditions. They add a pop of color to any setup and thrive in groups with other peaceful species.

4. Flowerhorn Cichlid

colorful flowerhorn cichlid — Image Credit: Junner rivera, CC BY-SA 3.0, Wikimedia Commons.

The flowerhorn cichlid is a vibrant, eye-catching fish known for its large, protruding “nuchal hump” on its head. These fish come in a range of colors, including red, yellow, and gold, and are considered lucky or auspicious in some cultures. They are territorial and require a spacious tank but are highly rewarding for owners who appreciate their unique look and bold personalities.

5. Mandarinfish

Mandarinfish in an aquarium — Image Credit: Micha L. Rieser/Luc Viatour, CC BY-SA 2.5, Wikimedia Commons.

The mandarinfish is known for its brilliant colors, including iridescent blues, greens, and oranges. These small, peaceful fish are a showstopper in saltwater aquariums. However, mandarinfish require a well-established tank with plenty of live rock and copepods for them to feed on, so they are best for experienced aquarium owners.

6. Lionfish

Red lionfish (Pterois volitans) — Image Credit: H. Zell, CC BY-SA 3.0, Wikimedia Commons.

With their stunning, venomous spines and distinctive appearance, lionfish are a popular choice for saltwater aquariums. These predatory fish are known for their dramatic beauty, but they also need careful attention to ensure they are properly fed and housed. Lionfish do best in aquariums where they can be kept alone or with large, compatible species.

7. Peacock Cichlid

A malawi cichlid fish, aka peacock cichlid fish, of genus Aulonocara — Image Credit: Shutterstock.

The peacock cichlid, named for its beautiful, iridescent scales that resemble a peacock’s plumage, is a striking freshwater fish native to East Africa. They are highly territorial and require a larger tank to accommodate their space needs. These fish are perfect for aquarium enthusiasts who appreciate vibrant colors and unique personalities.

8. Neon Tetra

Neon Tetra (Paracheirodon innesi) — Image Credit: Holger Krisp, CC BY 3.0, Wikimedia Commons.

Small yet striking, neon tetras are famous for their bright blue and red coloration, making them a favorite in both community tanks and aquariums that feature schooling species. These peaceful fish thrive in groups and adapt well to various water conditions. Their active and playful nature adds vibrancy to any tank.

9. Arowana

Head of an arowana fish — Image Credit: Marcel Burkhard, CC BY-SA 3.0, Wikimedia Commons.

Arowanas are large, predatory fish that are native to South America, Southeast Asia, and Australia. Known for their impressive size and sleek, metallic bodies, Arowanas are often described as “living fossils.” These fish can grow up to 3 feet in length, so they require a large tank with plenty of space. With their long, graceful fins and almost dragon-like appearance, they make a striking centerpiece in any aquarium.

10. Rainbowfish

Melanotaenia boesemani (Boeseman's Rainbowfish) — Image Credit: Eileen Kortright, CC BY 2.5, Wikimedia Commons.

Rainbowfish are colorful, lively, and come in various hues, making them a beautiful addition to any freshwater aquarium. Their gentle temperament and active nature make them a great choice for community tanks. Rainbowfish are also relatively hardy, making them perfect for both beginners and experienced aquarium hobbyists.

Choosing a unique pet fish for your aquarium can enhance your space with vibrant colors, fascinating behaviors, and a sense of tranquility. Whether you prefer the striking beauty of a discus fish or the peacefulness of rainbowfish, there are countless options to create a one-of-a-kind aquatic environment. However, it’s essential to consider the care requirements of each species to ensure they thrive in your tank. From freshwater to saltwater varieties, the right fish can transform your aquarium into a stunning aquatic display that will captivate both you and your guests.