Blue fish don’t just swim — they steal the show.
They shimmer like sapphires, glide like underwater jewels, and instantly turn any aquarium into a living masterpiece. Whether you’re a newbie with a ten-gallon tank or a seasoned aquascaper plotting your next showstopper, a splash of blue is the magic touch your setup craves.
These aren’t your average fin-flappers. We’re talking electric flashes of cobalt, deep indigo elegance, and personalities that can rival your dog’s. Some are tiny and chill, others bold and bossy — all of them downright irresistible.
Ready to fall in love? From the iconic Blue Tang to the unexpectedly fabulous Blue Guppy, we’ve rounded up the 18 best blue fish that’ll make your aquarium glow like a dream. Let’s dive in — because life’s too short for boring fish.
Blue Tang
The Blue Tang, known for its electric blue body and striking yellow tail, is a showstopper in any tank. Its playful nature and striking appearance make it a favorite among aquarists. Despite its beauty, the Blue Tang requires ample swimming space and a diet rich in marine-based foods.
Known for its role in the animated movie, this fish is more than just a pretty face. It’s social and often seen darting joyfully through the water.
If you’re considering adding a Blue Tang to your setup, ensure you have a tank of at least 100 gallons.
Electric Blue Acara
The Electric Blue Acara boasts radiant scales that shimmer under aquarium lighting. This medium-sized cichlid is known for its peaceful nature, making it an excellent addition to community tanks. Its striking color contrasts beautifully with green plants, creating an aquatic masterpiece.
This fish thrives in a well-maintained tank with clean water and plenty of hiding spots.
Though they are generally peaceful, Electric Blue Acaras can be territorial during breeding. Offering them a balanced diet will enhance their vibrant hue and keep them healthy.
Blue Guppy
Meet the Blue Guppy, a tiny but captivating creature with iridescent blue scales that gleam in the light. This little fish is perfect for beginners and small tanks, adding a touch of elegance with minimal effort.
Known for their active and cheerful nature, Blue Guppies are often seen darting around playfully. They thrive in well-planted tanks and enjoy the company of other peaceful species.
Feeding them a varied diet of flakes, brine shrimp, and daphnia will keep them healthy and vibrant, ensuring they continue to dazzle with their beauty.
Blue Betta
The Blue Betta, with its flowing fins and radiant color, is a true aquatic jewel. Known for their striking appearance, Betta fish have a reputation for being solitary yet mesmerizing.
Their personalities shine through as they gracefully navigate their environment. Bettas prefer calm waters and can thrive in smaller tanks, making them perfect for desktop aquariums.
While these fish are relatively low maintenance, providing clean water and a varied diet will help them maintain their stunning appearance and vibrant health.
Blue Gourami
The Blue Gourami is a gentle giant with a calming presence, known for its labyrinth organ that allows it to breathe air. This feature makes it uniquely suited to various water conditions.
Their pale blue hues add a serene touch to any aquarium, and they mesh well with other peaceful species.
Blue Gouramis enjoy spacious tanks with hiding spots and floating plants. Their diet is quite flexible, but offering them live foods occasionally will boost their vibrancy and overall well-being.
Neon Tetra
Neon Tetras are a classic choice, with their vibrant blue and red stripes creating a dazzling display. These tiny fish are social creatures best kept in schools, adding movement and color to your tank.
Their peaceful nature and small size make them ideal companions for other similarly tempered species. Neon Tetras thrive in well-planted tanks with subdued lighting that accentuates their colors.
Offering a mix of flake foods and occasional live treats will keep them healthy and active, making them a delightful addition to any aquarium.
Blue Ram
The Blue Ram, a dwarf cichlid, captivates with its striking coloration and charming personality. Though small in size, these fish are big on character, often displaying interactive behaviors with their owners.
They prefer warm, soft water and thrive in well-planted tanks with plenty of hiding spots.
While generally peaceful, Blue Rams can become territorial during breeding. Providing a diet rich in protein will enhance their colors and support their health, making them a vibrant and engaging choice for aquarists.
Blue Discus
The Blue Discus is often considered the king of the aquarium due to its regal appearance and demanding care requirements. Their round bodies and striking blue hues make them a focal point in any tank.
These fish require pristine water conditions and a diet of high-quality foods to thrive.
Though they can be challenging to care for, the reward is a breathtaking display of elegance and color. Discus fish prefer to be kept in groups, where they can socialize and show off their graceful swimming patterns.
Blue Angel Fish
Blue Angel Fish are a magnificent presence, with their elongated fins and serene demeanor. Often seen gliding through the water, they bring a touch of grace and sophistication to any aquarium.
These fish are best kept in spacious tanks with ample swimming space and a variety of hiding spots.
Their diet includes both plant-based and protein-rich foods, which help maintain their stunning appearance. Blue Angel Fish are relatively hardy, making them a captivating choice for both novice and experienced aquarists.
Blue Damsel
The Blue Damsel, with its iridescent blue scales, adds a striking pop of color to any marine aquarium. These fish are known for their hardiness and ability to adapt to various tank conditions, making them a popular choice for beginners.
Despite their small size, Blue Damsels are spirited and can display territorial behavior, especially in confined spaces.
Providing them with a tank that offers plenty of hiding spots and a diverse diet will keep them healthy and vibrant. Their lively nature and bold color make them a standout choice.
Blue Rasbora
The Blue Rasbora is known for its captivating iridescent blue hue. These small, peaceful fish are perfect for community tanks. Their shimmering scales reflect light beautifully.
In an aquarium, they add a gentle splash of color. The Blue Rasbora prefers a planted tank, where it feels safe and thrives. It’s a schooling fish, so keep them in groups of at least six.
Known for being easy to care for, the Blue Rasbora is suitable for beginners. Just provide clean water and a varied diet, and watch them shine!
Blue Mandarin
The Blue Mandarin is a true spectacle, with its psychedelic patterns and vibrant hues. Known for their grace and beauty, these fish are a stunning addition to any reef tank.
They require a mature tank with plenty of live rock to graze on microfauna, which is a crucial part of their diet.
Although they are relatively peaceful, Blue Mandarins can be challenging to care for due to their specific dietary needs. Providing the right environment will allow them to thrive and captivate with their mesmerizing appearance.
Powder Blue Tang
The Powder Blue Tang is a visual delight, known for its striking blue body and vibrant yellow and black accents. These fish are active swimmers and require plenty of space to roam.
They thrive in large reef tanks with ample hiding spots and a varied diet that includes marine-based foods.
Their stunning coloration and lively personality make them a favorite among aquarists, but they do require careful attention to water quality to remain healthy and vibrant. Powder Blue Tangs are a captivating addition to any marine setup.
Blue Chromis
Blue Chromis are small, vibrant fish that bring a splash of color and movement to marine aquariums. These peaceful fish are often seen swimming in schools, creating a mesmerizing underwater display.
They prefer tanks with plenty of open space and rock formations. Blue Chromis thrive on a varied diet that includes both flake foods and frozen marine preparations.
Their friendly nature and hardy constitution make them an excellent choice for both novice and experienced marine aquarists. Watching a school of Blue Chromis can be a truly calming experience.
Blue Hap Cichlid
Blue Hap Cichlids are a striking freshwater species known for their vivid coloration and bold personalities. These fish are best suited for larger tanks with plenty of rocky hiding spots.
While generally peaceful, they can become territorial, especially during breeding. A diet rich in protein will enhance their natural colors and support their health.
Their captivating appearance and engaging behavior make them a popular choice for cichlid enthusiasts. Providing them with a suitable environment will allow them to thrive and showcase their vibrant colors.
Blue Gularis Killifish
The Blue Gularis Killifish is a striking addition to any tank with its vivid blue body and flowing fins. This species is a showstopper with a personality to match.
These fish have a fascinating behavior, often seen darting energetically around the tank. They thrive in a well-planted environment with subdued lighting.
A semi-aggressive nature means they are best kept with similarly sized tank mates. They add a dynamic visual appeal with their vibrant colors and active lifestyle.
Blue Gudgeon Dartfish
The Blue Gudgeon Dartfish is a slender, graceful fish known for its quick movements and shimmering blue body. These fish are a lively addition to marine tanks, where their agility can be fully appreciated.
They prefer tanks with sandy substrates and plenty of hiding spots. A diet rich in meaty foods will keep them healthy and maintain their vibrant coloration.
Their active nature and striking appearance make them a captivating choice for marine enthusiasts. Observing their darting movements is both fascinating and entertaining.
Blue Green Chromis
Blue Green Chromis are a beloved choice for marine aquarists, known for their peaceful nature and shimmering hues. These fish are often seen swimming in schools, adding a dynamic display to the aquarium.
They thrive in reef tanks with ample swimming space and rock formations to explore. A varied diet that includes both flake foods and marine preparations will keep them healthy and vibrant.
Their tranquil demeanor and beautiful coloration make them a wonderful addition to any marine setup. Watching a school of Blue Green Chromis is a soothing experience.