22 Coolest Fish for Your Freshwater & Saltwater Aquarium – Collect Today

According to the National Pet Owners Survey done on 2017-2018, about 70% of people in America keep pet animals. Among them, 40% of people like petting the coolest fish breeds in their aquarium which are beautiful and peaceful, and rest of the people keep other pets in their home.

People like petting calm-natured or cool fish because they are easy to care. Most of the people are busy with their hectic lifestyle. So, keeping fish as their pet friend is quite easy than keeping other pets.

You just need to clean the aquarium weekly and feed them as per their requirements. Moreover, health practitioners say that watching colorful fish can reduce your stress and anxiety because the colors of the fish and the sound of the water relaxes your mind, and control your blood pressure. So, let’s take a look at some interesting facts and features of some coolest fish of your beautiful aquatic hub.

Coolest Freshwater Fish for Your Fish Home

As we know that freshwater fish are found in rivers, streams, ponds, and lakes, so most of them naturally cannot live in a saltwater aquarium. You need to check the parameter of the water before keeping any species in a fish tank.

The decoration of freshwater tanks is always simple and beautiful. You can keep freshwater plants, small rocks, fine gravels and small caves in the tank. These things will create a natural tropical environment for your pet fish.

Long we have discussed on the decoration of tropical aquarium, now let us know about some peaceful or coolest freshwater fish which are not only nonviolent but also easy to keep.

Key Specifications:

• Origin: East Asia (China, Japan)
• Size: 4” (10-16 cm)
• Tank Size: 20 gallons
• Lifespan: 10-20 years
• Diet: Omnivoros

When we plan about fishkeeping, the most common and popular name comes in our mind is Goldfish. Fish hobbyists think about keeping Goldfish in their tank because of several reasons.

The bright color, small size, and peaceful nature of this omnivorous species make it one of the coolest freshwater fish for beginners’ tanks. Not only one but there are various types of Goldfish in the same family like Comet Goldfish, Common Goldfish, Telescope Eye Goldfish, Shubunkin Goldfish, etc.

The features of all the fish are different from each other in color, pattern, and size, but all of them are stunning in appearance and easy to care. If you want to keep this Asian fish in your aquarium for ornamenting your fish home, then knowing its features and care guide may help you keep this stunning fish in your properly.

Key Specifications:

• Origin: South Asia
• Size: 2” (5 cm)
• Tank Size: 5 gallons
• Lifespan: 3-5 years
• Diet: Omnivoros

Danios are hardy and peaceful freshwater fish for tropical aquarium. Its adaptable and cool nature makes it a beginner-friendly fish, so both beginner and expert fishkeepers can keep this fish in their aquariums. There are various Danios like Giant Danio, Zebra Danio, Rosy Danio, and Pearl Danio.

You can pet any Danio because all are peaceful and hardy in nature. For keeping this fish in an aquarium, know about its food and habitation requirements. Such information will help you take care of this coolest fish of your tropical aquarium.

Key Specifications:

• Origin: South America, Western Brazil, Eastern Peru, and Southeastern Columbia
• Size: 15” (4 cm)
• Tank Size: 10 gallons
• Lifespan: 10 years
• Diet: Omnivoros

Tetras are of different types, but Neon Tetra is one of the most stunning fish which can comfortably live in small freshwater aquarium. People like petting this fish because of its bright bicolor pattern and size. Moreover, it is cool because of its peaceful temperament and hardy nature.

Some aquarists call it a jewel of tropical water because of its shinning body color. Knowing its features and care guide of this peaceful schooling fish will help you keep this fish in your aquarium comfortably.

Key Specifications:

• Origin: Brazil, Antigua, Jamaica, Guyana, Netherlands Antilles
• Size: 0.6-1.4” (1.5-3.5 cm)
• Tank Size: 10-20 gallon
• Lifespan: 1-3 years
• Diet: Omnivoros

Guppy fish is also a suitable fish for a small tank. It is known as the coolest fish because of its stunning multi-colored body and colorful fins. Guppies come in a wide range of colors, and keeping various Guppies in your fish tank will make the tank colorful.

The breeding system of this livebearer fish is very easy. So, novel fishkeepers prefer keeping this fish in its aquarium. However, for petting this fish, you have to know about its necessities. The complete care guide of Guppy Fish will help you maintain the living, eating and other requirements of the pet fish.

Key Specifications:

• Origin: Southern Mexico, Central America
• Size: 2.5” (6.35 cm)
• Tank Size: 10 gallons
• Lifespan: 3 years
• Diet: Omnivoros

Platy fish is one of the common fish breeds which is often found in most of the aquariums. This schooling fish is peaceful and easy to pet. Moreover, its beautiful tail and small size are also liked by the aquarists. So, they prefer to keep this adorable and coolest freshwater fish in their tank.

Platies can dwell in both residential and commercial tanks because it is an active and social fish. Also, Platies are not picky eaters, so you can feed any type of food that you want to feed your slim buddy.

Key Specifications:

• Origin: Indonesia, Guinea, Eastern Australia
• Size: 4” (10)
• Tank Size: 25-30 gallons
• Lifespan: 5-8 years
• Diet: Omnivoros

You may have seen colorful fish in children’s books, but they exist in reality also. If you want a splash of bright colors in your aquarium, then Rainbow Fish can be the perfect fish for your aquatic world.

The body of this fish is shaded with multiple colors that can refresh your eyes and mind. Generally, this fish is found in small lakes, streams, and ponds. Rainbow Fish prefers living with a shoal of fish, so you can easily keep this fish in a community tank. However, you need to arrange some caves, floating plants and other hiding places for this shy fish, so that it can take rest and hide whenever required.

Key Specifications:

• Origin: Malaysia, South America
• Size: 2” (5.08 cm)
• Tank Size: 10 gallons
• Lifespan: 5-8 years
• Diet: Omnivoros

Are you finding colorful, gorgeous, peaceful and easy-natured fish? You will get all these positive qualities in Harlequin Rasbora. So, this coolest fish is seen in most of the residential and commercial fish tanks.

Rasboras are not a picky eater, and they don’t have any specific choice in finding food. You can feed both vegetative and meaty foods to this fish. Usually, this fish is found in the blackwater river near South America. You will also find this schooling fish with a shoal of other fish breeds in lakes and streams.

Key Specifications:

• Origin: Mexico
• Size: 3” (6.7 cm)
• Tank Size: 10 gallons
• Lifespan: 5years
• Diet: Omnivoros

This coolest freshwater fish is different from other tropical fish because it can live in both freshwater and saltwater. Mollies prefer living in densely planted fish tanks that have proper illumination. The fins and tails of Molly Fish are quite attractive, and when they swim with a school of fish the water dazzles like an electric current because of its bright and shimmer shade and pattern.

Not only one, but there are various types of Molly Fish like Black Molly, Sailfin Molly, Balloon Belly Molly etc. that can live with a shoal in community tanks. The easy breeding nature of this livebearer fish is liked by most of the aquarists, so arrange a nano tank for this small freshwater fish with plenty of live plants and small caves.

Key Specifications:

• Origin: Amazon River of South America
• Size: 2” (5 cm)
• Tank Size: 10 gallons
• Lifespan: 2-5 years
• Diet: Omnivoros

The unique appearance of Marble Hatchet Fish makes it one of the coolest fish of tropical water. This passive-natured fish is generous but it has a nature to jump and come outside the tank, so try to arrange a tight lid for this tank.

Moreover, this fish prefers swimming on the upper surface of the water. Try to keep them in low temperature water, so that they feel comfortable because they don’t prefer living in mildly warm water.

Key Specifications:

• Origin: Indonesia
• Size: 4” (10 cm)
• Tank Size: 20 gallons
• Lifespan: 10 years
• Diet: Omnivoros

This bottom-dwelling fish is an algae eater, so it is known as a bottom feeder. Kuhli Loach is a nocturnal fish that stays awake whole night like an owl. It is a scavenger, so it consumes the waste of an aquarium. This peaceful fish helps fishkeepers by cleaning the tank where it lives.

The snake-like structure of Kuhli Loach is quite amazing, but its nature is not furious like a snake. So, beginner fishkeepers also like petting this fish. A spacious tank is needed just because of its long height.

Key Specifications:

• Origin: Malaysia, Thailand, Indonesia, Vietnam, and Cambodia
• Size: 5” (12.17 cm)
• Tank Size: 30 gallons
• Lifespan: 8 years
• Diet: Omnivoros

The transparent body of this luminous fish makes it the coolest fish in your aquarium. It is cool both by its appearance and by its nature. You can see the entire internal bones of this fish because of its glass-like transparent body. Other names of this uncommon fish are X-Ray Catfish and Phantom Catfish, which goes with its appearance.

When 6-7 Glass Catfish swims in an aquarium, they look like a bunch of skeletons. This fish may look weak but it is a hardy fish, and it can live in different types of water conditions.

Coolest Saltwater Fish for Your Aquatic World

Do you want to see the marine beauties in your fish home by collecting varieties of coolest saltwater fish? Definitely, you can do that! Before that, you need to decorate a saltwater tank with marine plants, shells, gravels, oysters and many other oceanic beauties.

If you create a natural environment under the water, then your marine pet fish can comfortably dwell in it. Have a look at some saltwater fish that are cool in look and nature.

Key Specifications:

• Origin: Northern Coast of South America
• Size: 3” (7.62 cm)
• Tank Size: 30 gallons
• Lifespan: 5 years
• Diet: Carnivoros

The appearance of Royal Gramma is just like an animated fish because of its rainbow color. The vibrant colors are like a splash of hues spread in an aquarium. This is one of the coolest features of this fish.

Royal Gramma prefers living in an eco-friendly tank decorated with marine plants. You should also add plenty of rocks, caves, and shells in its tank. Caves are needed because it is a shy and peaceful fish that hides in the caves and behind the plant when it is attacked by any predator.

Key Specifications:

• Origin: Pacific Ocean, Red Sea, Indian Ocean, Australian East Coast, Great Barrier Reef
• Size: 4.3” (10.92 cm)
• Tank Size: 20 gallons
• Lifespan: 6-10 years
• Diet: Omnivoros

Have you seen the film, Finding Nemo? Yes, we are talking about the cute Nemo which is characterized by Clown Fish. So, isn’t it a cool fish for your marine aquarium?

Clownfish is the easiest saltwater fish because its care level is easy, and it is peaceful in nature. Aquarists like this fish because of its beautiful orange-white body which has long black lines. Its cute eyes are admirable to every fish enthusiast who like marine fish for their aquatic world. Children love this fish very much, so for them it is one of the coolest fish of marine water.

Key Specifications:

• Origin: Red Sea
• Size: 6” (15.24 cm)
• Tank Size: 120 gallons  
• Lifespan: 5-10 years
• Diet: Omnivoros

The name Butterflyfish is suitable to its appearance because this saltwater fish exactly look like a butterfly because of its size, color, and pattern. So, if you like butterflies, then you will definitely like keeping Butterflyfish in your aquarium.

Among various Butterflyfish types, you can keep any of them in your marine fish world. Not only one, but there are also various colors of Butterflyfish like blue, white, yellow, red, orange, and black. You need to arrange a large reef-work decorated tank to create a natural environment for the saltwater fish.

Key Specifications:

• Origin: Guiana, South America
• Size: 4” (10 cm)
• Tank Size: 70-100 gallons
• Lifespan: 19.7” (50 cm)
• Diet: Carnivoros

Angelfish is known as the queen of ocean and river because it can live in both tropical and brackish water. The angelic beauty, calm behavior and hardy nature of this fish make it one of the coolest saltwater fish. It does not have any special water requirement, as it can adjust in different types of water with various temperatures.

The disk-shaped body and angel-like fins of this fish provide it a stunning beauty. You will find various shades and patterns in different kinds of Angelfish. However, it is a shy fish, so try to keep it with peaceful breeds, and arrange hiding places in your aquarium for this fish.

Key Specifications:

• Origin: Southern Japan
• Size: 2” (5.08 cm)
• Tank Size: 30 gallons
• Lifespan: 5 years
• Diet: Herbivoros

You may have seen herbivoros animals, but vegan fish are found less in the marine world. One of the amazing herbivoros fish found in saltwater is Yellow Prawn Watchman Goby.

Usually, this fish prefers living in a natural and eco-friendly tank that is covered with plants and reefs. It is easy to keep because of its calm nature and small size, but you need to arrange a tight lid for the aquarium because Gobies have a tendency to jump high and come out of the aquarium.

 Key Specifications:

• Origin: Indo-Pacific Ocean, Red Sea
• Size: 4” (10.16 cm)
• Tank Size: 30 gallons 
• Lifespan: 5 years 
• Diet: Omnivoros

Chromis are found in blue and green with light green spots on its entire body. Keeping this calm species in your beginner-friendly saltwater aquarium is a good decision but you should not keep this fish with fast-swimmer species because Blue or Green Chromis are slow-swimmers that cannot adjust with fast swimmers.

You will find this fish in the lagoons under the deep ocean. It prefers living in the bottom of the fish tank surrounded by ocean rocks, marine plants, caves, corals and reefs.

Key Specifications:

• Origin: Western Pacific Ocean, Australia, Philippines, Indonesia, Malaysia
• Size: 3” (7.6 cm)
• Tank Size: 30 gallons
• Lifespan: 5 years 
• Diet: Carnivoros

If you like watching dash of colors in the aquatic home of your pet fish, then Mandarin Fish is really a cool choice for your marine tank. If you see the patterns and lines on the body of a Mandarin Fish, it will really look like a creative art or a painting. Therefore, fishkeepers like to add this colorful and peaceful fish to adorn their tank.

Mandarin likes to live in warm water, so try to keep mild-warm alkaline water in the tank. The structure of Mandarin Fish is somehow similar to shape of Goby Fish but it is not a high jumper like Gobies.  

Key Specifications:

• Origin: Tropical and Sub Tropical Regions
• Size: 8” (20.32 cm)
• Tank Size: 30 gallons
• Lifespan: 10-20 years
• Diet: Carnivoros

Nowadays, the popularity of uncommon and unconventional fish for aquariums are rising more. If you are also finding an uncommon fish that is both cool in its look and behavior, then Pipefish is a perfect choice for your tank.

Gone are those days when people wanted to keep common Goldfish and angelfish in their fish tank. Today, people are trying to bring variety in their aquatic pet home by adding long sea-horse like Pipefish. The striking appearance, active energy bring dynamism in a fish tank. Among 200 types of Pipefish, only some fish can be captivated.    

Key Specifications:

• Origin: East Africa, Australia, U.S.A, Melanesia, India, and Indonesia
• Size: 16-30” (40-76 cm)
• Tank Size: 200 gallons
• Lifespan: 5-12 years
• Diet: Omnivoros

Have you ever seen any bat-shaped fish in an aquarium? Some aquarists have seen and some are less aware of this uncommon batfish. Some fishkeepers may think that this fish is an aggressive species of saltwater, as bats are aggressive. However, the temperament of batfish is completely different from its nature. So, most of the fish enthusiasts like petting this peaceful fish.

Not only calm, but this fish is also social with other aquatic species which represents it as a cool fish. Moreover, it is not a picky eater, and it can eat any type of vegetative and meaty foods. All these features make it easy to keep in an aquarium.  

Key Specifications:

• Origin: Red Sea, Indo-West Pacific Ocean
• Size: 3” (7.62 cm)
• Tank Size: 30 gallons
• Lifespan: 5 years
• Diet: Carnivoros

Fishkeepers admire the color and pattern of the most beautiful Six Line Wrasse. You will find six colorful lines on the body of this fish, so it is known as Six Line Wrasse. The bright and beautiful eyes of this fish attract the fishkeepers.

This species does well when kept with a moderate amount of fine rocks in an aquarium. Morsel is one of the favorite foods of Six Line Wrasse among other meaty foods, so it will be better if you arrange live morsel for your pet fish along with blood worms and shrimps.

Key Specifications:

• Origin: Caribbean Sea
• Size: 8” (20.32 cm)
• Tank Size: 30 gallons
• Lifespan: 10-15 years
• Diet: Omnivoros

The parrot-like appearance of this fish is the reason that it is known as Parrot Fish. Not only green color, but the parrot-like pattern and its fused teeth are reasons that it is known as Parrot Fish.

Fishkeepers prefer keeping this fish in its aquarium because it is an algae eater and a tank cleaner. There are various species in the family of Parrot Fish. Now, you need to choose what type of Parrot Fish you want to add in your aquatic home.

We hope the ideas about the aforesaid fish breeds will help you keeping the coolest fish in your tank. Just acquire petite knowledge about those fish, so that you can take care of your swimmer friend.

More Popular Fish for Fish Tank

Apart from these coolest freshwater and saltwater fish, there are other popular fish. You can go through the facts, features and care guides of those fish if you are a fish hobbyist: