Our world is described as the “Blue Planet.” And when you consider that 70% of the Earth’s surface is covered with water, that’s no surprise.
So, hundreds of thousands of fish live in our oceans, rivers, lakes, and other bodies of water. Many of these fish are incredibly beautiful, and some can be kept in your home aquarium if given the right conditions and care.
Read this guide to discover our top 12 most beautiful fish in the world.
We think these stunning-looking fish are just about the most beautiful in the ocean!
The Mandarin goby is a marine fish found in the Pacific Ocean, inhabiting inshore reefs and sheltered lagoons.
Mandarin gobies have several quirks that make them a fascinating and beautiful fish species.
They are one of only two species in the world that can produce their own vibrant blue colors. Other creatures that appear blue, such as peacocks, cannot actually make blue pigment. These animals have colorless cells that reflect light, making the creature appear blue.
Mandarin gobies are covered in tiny spikes that deliver toxic mucus to anyone or anything attempting to touch the fish. That protects the fish from predators and makes handling them tricky for reef aquarium keepers.
Although you can keep Mandarin gobies in a saltwater tank, they are notoriously difficult to keep healthy, primarily due to their highly specialized dietary requirements.
The incredibly striking Clown Triggerfish is one of the most gorgeous fish in the ocean.
The fish’s lower body is dark-colored and covered with big white spots. Above that, the fish is yellow with small black dots. The fish has a white or yellow stripe across its face, and the snout is also yellow.
Juvenile Clown Triggerfish are often very reclusive, but as they reach adulthood, the fish’s personality shines through, becoming more territorial.
You can keep these fish with other larger marine species. However, if you decide to keep Clown Triggerfish with other semi-aggressive types, you should add the Triggerfish last.
You’ll need a large tank if you’re planning on keeping these beautiful colorful fishes, as they need plenty of swimming space and somewhere to hide if the mood strikes.
The Regal Tang is a stunning fish made famous by the film “Finding Nemo” as the character, Dory.
The Regal Tang is also known as the Hippo Tang, Common Surgeon, Palette Surgeonfish, and Pacific Blue Tang.
These gorgeous tropical fish have bright blue oval bodies and a yellow tail and pectoral fin. Adult Regal Tangs have a dark blue line running through the dorsal fin, curving at the back of their tail.
As the fish mature, their colors change. Juveniles are brilliant yellow with blue spots close to their eyes and pale blue fin tips. Adults have a deeper blue body.
The Lionfish is found in the Pacific Ocean and is also known as the Tiger fish, Dragon fish, and Scorpion fish. These fish can be from two to sixteen inches long and have gloriously striped bodies that show a zebra-like pattern.
Lionfish are considered an invasive species of fish in North America since they have no natural predators and tend to wipe out native fish species in areas they colonize.
These fish reproduce incredibly rapidly, releasing up to 30,000 eggs every seven days! Lionfish are also highly adaptable, easily fitting into new environments. These venomous fish hunt by attracting smaller fish with their feathery fins where the prey is captured.
Lionfish also have large venomous spikes that they use as a defense mechanism. Swimmers and divers are often stung by these fish, and although the stings cause nausea, vomiting, and dizziness, the creature’s venom is not fatal.
Clownfish are also movie stars, appearing alongside Dory in the “Finding Nemo” movie. These fish are found in the coastal coral reefs of Southeast Asia and Australia.
Clownfish are also sometimes called Clown Anemone fish because of the fish’s symbiotic relationship with sea anemones. The fish have evolved with an immunity to the anemone’s toxin and use their adopted host for shelter and protection from predators. The anemone benefits by receiving food from the fish and enjoying a cleaning service, too.
Interestingly, Clownfish are hermaphrodites. That means the fish are all born male but can turn female if numbers necessitate. However, once the change has been made, the fish can’t turn back into males. The larger, more dominant fish becomes the female in pairs of fish.
The Moorish Idol is a large, beautiful fish often regarded as a staple subject by underwater photographers.
The fish lives on the coral reefs in the tropical and subtropical waters of the Indo-Pacific Ocean. These gorgeous animals have contrasting black and white stripes, a brilliant yellow patch at the back of their bodies, and long snouts with a vibrant orange/yellow mask. The Moorish Idol has a long, eye-catching filament that runs from the fish’s dorsal fin tip.
Unfortunately, these fish are not easy to keep in captivity because of their specialized diet and the minimum tank size they need.
Despite the Moorish Idol’s close resemblance to the Butterflyfish, the two are unrelated.
As you might guess from their name, the Banggai Cardinalfish is native to the Banggai Islands in Indonesia.
These nocturnal fish inhabit seagrass beds and coral ledges, hiding away until darkness falls when they emerge to feed, often in groups of up to 200 individuals.
Banggai Cardinalfish are sociable, peaceful fish that you need to keep in groups of at least eight in community tanks. You’ll need a spacious tank with lots of open swimming space and hiding places. Keeping the fish in an overcrowded small tank can lead to aggressive, territorial behavior.
These fish are seldom seen in fish stores, although you can buy them from online breeders.
The Symphysodon Discus fish makes a stunning centerpiece in any large freshwater aquarium. These fish are also known as the Pineapple fish or Heckel Discus.
The fish’s round, disc shape reaches around six inches in diameter, presenting a graceful, elegant picture as the creature glides through the water. Heckel Discus comes in a wide range of different colors, although the crimson red color is generally regarded as one of the most beautiful.
The Symphysodon Discus comes from various parts of the Amazon River in South America, where they live in large groups. These beautiful fish are not easy to keep since they are picky eaters and require pristine water conditions to thrive, so we don’t recommend the Discus as a fish for beginners.
Betta fish, also called Siamese Fighting Fish, are one of the most popular tropical fish in the aquarium community.
Bettas have been bred over hundreds of years to display various tail shapes and an eye-watering range of vibrant colors. You can’t keep two male bettas in the same tank as they were initially bred to fight and can have a highly aggressive nature.
These freshwater fish can be kept in nano tanks with just a few shrimp or a snail for company, and they can even form a bond with their owner. You can even teach your betta simple tricks, too!
Wild bettas live in marshes, ditches, rice paddies, and ponds and are generally dull greenish-brown in color, so they’re camouflaged and protected from predators. Captive bettas, however, are absolutely beautiful!
Interestingly, betta fish can breathe atmospheric air through their gills like regular fish. They do that by gulping air at the water’s surface, which passes through the fish’s labyrinth organ, which extracts the oxygen.
That evolutionary quirk enables the fish to survive in water where oxygen levels are very low. During the dry season, the fish jump from puddle to puddle in search of food and to keep away from other males.
Threadfin Butterfly Fish
The Threadfin Butterflyfish is one of the most popular aquarium fish among reef enthusiasts. These gorgeous marine fish can grow to reach nine inches in length, so you need a large tank of at least 100 gallons to accommodate them.
Butterflyfish are easy to care for and peaceful, so they fit nicely into a community marine or reef tank. Although most are wild-caught, the fish adapt well to living in captivity, making them a favorite fish with beginners.
Butterflyfish have a pearl-white-colored body, blending into a vivid, sunshine yellow color toward the fish’s tail and up into the dorsal fins. A striking pattern of diagonal black perpendicular lines creates a chevron design, making this fish truly eye-catching.
All angel fish are gorgeous, but Regal Angelfish are elegant creatures whose beautiful colors can make an absolutely stunning display in a large aquarium.
However, these fish are not the easiest to keep, as older specimens find it very difficult to adapt to life in captivity. However, smaller juvenile specimens generally fair better than mature adults. Also, the fish grow to around ten inches long, so they need a tank of at least 100 gallons to be happy.
In the wild environment, the Regal Angelfish is found in the western and northern Indian Ocean, the Indo-Pacific region, and the Red Sea. The fish inhabits reefs with plenty of caves, crevices, cracks, and other hiding places.
These fish live alone or in mated pairs. If you buy a Regal Angelfish, always pick one that originates from the Indian Ocean or the Red Sea. Fish taken from the Indo-Pacific are often caught using chemicals and generally don’t live for very long.
French Angelfish are found in the Bahamas, the Caribbean, and Florida shallow reef habitats.
The fish changes in appearance as it matures from its juvenile life stage until the body becomes a graduated dark black/gray color with a scattering of yellow flake-like markings.
If you want to keep one of these popular fish, you must keep only one. Although they live in pairs in the wild, they become highly territorial fish in captivity. You need to provide the French Angelfish with lots of hiding places in the form of rockwork, but they also need lots of open swimming space.
When introducing the French Angelfish to a community tank, be sure to add these fish last so that these potentially aggressive fish haven’t already claimed a territory.
I hope you enjoyed our list of the world’s top 12 most beautiful aquarium fish! If you did, please share the article before you go!
Although many of the beautiful species we featured come from marine environments and are really only suitable for experienced aquarists to take on, there are also some species of freshwater fish that are a great choice for beginners.
Do you own any of the fish we mentioned in this guide? Tell us about your fish in the comments section below.