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Reasons most fish keepers have aquariums is to improve their home aesthetics, plus enjoy watching their aquatic pets go around their business.
As a result, you’ll want colorful fish to epitomize this experience, but by far, the coolest species to own are those that have a variety of hallmarks. This includes breathtaking colors, stunning characters, unique physical attributes and subtle demeanor.
Thats said, in this article, I’ll let you know which fish to keep if you are looking for an all-around cool freshwater fish.
Some Cool Fish are Colorful
Color plays a big role in the appearance of your tank. You could choose to use bright decorations and gravel to spruce the tank. However, it’s better if you animate your tank with moving inhabitants.
Which means choosing colorful, vibrant freshwater fish that standout will is worth your while.
Consider one of these 5 colorful fishes.
Cool Fish #1— Killifish
Killies are a lavish family of freshwater species distantly related to the more common mollies, guppies, platies and swordtails.
They are one of a kind vibrantly colored and beautifully patterned species. Altogether, there are some 1270 different species of killies with each fish displaying unique traits.
Most of them are small, from one to two inches, with the largest fish growing to just under six inches. Hence, most killifish species are easy to keep in aquariums.
Striped panchax also called golden wonder killifish are the most commonly found in pet stores.
However, killies are a little challenging to keep which mean you’ll need a certain level of expertise and consequently not beginner friendly. I recommend you have at least 2 years of fish keeping expertise before you add them to your fish tank.
Cool Fish #2 — Boesemani Rainbowfish
These beauties are not only prized for their color but also their peaceful demeanor. Their color patterns are completely different from other rainbow fish. They have half orange-red rears and bluish-grey or purple front bodies.
Intrestingly, Boesemani rainbows are capable of adjusting their color intensity which may be either a sign of mood or health.
They are best when kept in groups and are also perfect for community tanks. Bosemanis prefer shallow tanks with thick aquatic vegetations.
Unfortunately, they are challenging and not recommended for beginner aquarists. They also grow fairly big thus not ideal for small tanks that are less than 20 gallons.
Cool Fish #3 — German Ram Cichlid
German blue rams are cool dwarf cichlid appreciated for their bright oranges and electric blues. They also have a peaceful temperament.
The fish have many common names alluding to their popping hues. They are commonly called blue rams, golden rams, butterfly cichlids or dwarf butterfly cichlids.
A male German Ram reaches 2.7 inches in length, but females stay a bit smaller. The main body color is yellow-green and decorated with blue dots that extend into the fins.
They also have seven faint interrupted dark vertical stripes on the flanks and one intense stripe that runs vertically across the head and through the eye.
German rams are guaranteed show stoppers in community aquariums where other cichlids are not well suited.
However, while generally good community fish, they can be territorial at times and also grow fairly big. Hence consider at least a 20-gallon fish tank for a pair of german blue rams.
Cool Fish #4 — Cherry Barb
Cherry barbs are small fish with elongated and relatively compressed bodies. They are a schooling species hence best kept in groups of at least six fish to best bring out their aesthetics.
Cherry barb bodies are on average 1 to 2 inches long with brown- green and reddish or cherry red bottoms which are separated from the sides by brown-red lateral lines.
They are fairly peaceful and can live even in community tanks. Cherry barbs are also quite easy to keep and good for beginners which further adds to their cool aspects.
However, they do get quite sensitive to water conditions so keep them in well-maintained tanks with stable parameters and clean water. They also love densely packed aquarium with a lot of plants and decorations.
Cool Fish #5 — Green Spotted Puffer
These puffers are subtle beauties with a yellow-green color on their bodies with black spot and a white belly plus fins and tails that have a light green hue.
Green spotted puffers can be kept with others of the same kind, or other fish, but they are rather aggressive and will often nip the fins or scales of slow-moving tankmates.
Moreover, spotted puffers are not easy fish to care for and so you’ll need to do some thorough research before bringing them home.
Understading their behavior, care, and tank requirements will go a long way to making sure your puffers live long and happy lives.
One important fact to note is green spotted puffers can be kept in freshwater as juveniles but must be switched over to brackish water when they mature.
They also are thick bodied fish that grow to an adult length of about six inches hence live best in considerably bigger tanks. And are best when housed in a single species aquarium.
Other Cool Fish Have Distinctive Features
Certain freshwater aquarium fish have fascinating features which many hobbyist love, as a result, among them are some of the most popular aquarium species.
These unique traits range from fin shapes to body patterns and even elongated organs.
Let’s look at #6 to #10: Coolest freshwater aquarium fish with outstanding attributes.
Cool Fish #6 — Betta Fish (Siamese fighting fish)
Betta fish are the real deal, they are bold, sassy, stunning and awfully intelligent.
Over and above, the two most astounding traits are their colors and flowy fins and tails. Though their all-around badass reputation doesn’t fall too far behind.
For these reasons, bettas are by far the most popular freshwater aquarium species.
They usually grow to a length of about 2.6 inches.
Aquarium bettas come in brilliant colors that range anywhere from yellow, red, blue, purple, green, pink, white, black, orange to a mix of more than one of this color on a single fish.
They also come with different tail configurations including veil, comb, crown, delta, double, half moon, plakat, rose, feather, round and spade tails.
Male bettas are especially reputable because they have stronger and more glaring features. They also flare more frequently because they are naturally more aggressive, which is a unique trait you can observe when you want to enjoy or play with your cool fish.
Betta fish are considerably hardy though they are affected by water ph levels hence prefer neutral conditions. Luckily, they can live even in small 5-gallon tanks, considering they are territorial and not suitable candidates for community aquariums.
They can also tolerate low oxygen tanks because they have labyrinth organs that allow them to breathe on the water surface. If you are keen enough, you’ll notice your betta come up in the tank, gulp some air then venture back into the water.
However, the last thing you want is to put two male bettas in the same fish tank, they will literally fight to death.
Nonetheless, betta are fairly easy to take care of and a good choice even for beginners aquarists.
Cool Fish #7 — Angelfish
Angelfish like bettas are some of the most loved freshwater aquarium fish, as well as the most commonly kept cichlid.
They are prized for their unique shape, color, and behavior. Angelfish come in some beautiful color variants including striped zebra angelfish, gold angels, and koi angels.
The coolest factor is angels are unusually shaped being greatly laterally compressed with round bodies and elongated triangular dorsal and anal fins. Their unique body shape allows them to hide among roots and plants; often on vertical surfaces.
An adult angelfish can grow to a foot tall hence prefer bigger to smaller fish tanks. Plus avoid keeping with smaller fish because they will angels will devour them without blinking an eye.
Also, they can get aggressive hence not good for community tanks, they do best when kept with their own kind.
The right aquarium water conditions will lessen stress in angelfish and keep them healthier and happier.
Cool Fish #8 — Flowerhorn Cichlid
Flowerhorn cichlids are nothing short of ornamental. They are notable for their vivid colors, but their coolest feature is the distinctively shaped head for which they are named.
Disputably, they are man-made hybrids so they may not be exactly suitable for every aquarist.
The fish grow quite large reaching an adult size of over a food hence require large tanks. They can also be aggressive towards tankmates and even their owners.
Flowerhorns are bad candidates for community tanks, so it best to place them in single species tanks with their own kind. Also, they are fussy and require specific care and are overall a bad idea for beginning hobbyists.
Even if you are an experienced fish keeper, you’ll want to do thorough research before you purchase these beautiful cichlids.
Cool Fish #9 — Guppy
Guppies also called million fish or rainbow fish, are widely distributed tropical fish and some of the most popular freshwater aquarium species.
While natural type females are grey in color, males have beautiful splashes, spots or shapes that can be any of a wide variety of colors.
Another unique cool factor is their showy tails that conspicuously broaden behind overall slender bodies.
Guppies have also been largely selectively bred with hybrids characterized by different exotic colors, patterns, shapes, and fins, such as snakeskin and grass varieties.
They are small, versatile fish that grow to a typical length of about 1.2 to 2.4 inches long. Plus they have a peaceful temperament.
Guppies are, therefore, perfect for community aquariums and live best when kept with other tranquil species. Moreover, they are fast swimmers and will easily out swim the mostly slower big and aggressive species.
They also are hardy and easy to care for hence a good option for new fish keepers. Amazingly, guppies can withstand salinity levels that are 150 percent more than normal seawater which means they will live comfortably even in tropical marine tanks.
Keep your guppies in large groups to tap into their natural shoaling tendencies and better spruce your aquarium.
Cool Fish #10 — Green Swordtail Fish
Green swordtails are livebearers closely related to Southern platyfish and can even be cross-bred.
The name is derived from cool elongated lower lobe on male’s tail fins. However, females, which are a little bigger than their male counterparts lack the sword.
Natural form swordtails are brilliantly colored being green with red and brown lateral stripes and speckles on the dorsal, and sometimes caudal fins. Males are frequently yellow and edged in black below.
Tropical freshwater aquarium green swordtails have been bred into various exotic forms to achieve more colors and, as a result, many different types exist.
Male swordtails reach a maximum of 5.5 inches and females 6.3 inches.
The fish are hardy and don’t need too much space, however, place them in at least a 20-gallon fish tank. Moreover, if you plan on adding them in a community tank, consider at least a 40-gallon aquarium.
When not housed in a community tank, put them with other swordtails or their cousins: platies or mollies.
Green swordtails are generally peaceful and active and also quite social and enjoy good company. Although male fish are almost always aggressive towards other males of the same species.
Purchase any of these cool fish to enjoy your fish keeping experience. Also, check out the 10 coolest freshwater aquarium fish for small tanks (10-gallons).