March 11

Sarah Robertson

What Is a Mustard Gas Betta?

The Black Mustard Gas Halfmoon Betta (Betta Splendens) is a beautiful high-grade coloration fish from the original longfin variety of betta splendens. This fish has a dark blue to black body with brilliant yellow fins, resulting in a very distinct, identifiable color combination.

The Mustard Gas betta is a new member of the betta family, characterized by its bright iridescent blue or green body and yellow-orange fins. These fish are extremely hardy and able to breathe air from the surface, making them ideal "bowl fish," but they will do best in a modest aquarium with a heater and some form of filtration. Fights between males of this species are inevitable, and they must be kept alone; nevertheless, females may be kept in groups.

Appearance & Varieties:

They come from the family of betta Splendens. The Black Mustard Gas Halfmoon Betta is a longer-finned variety of the betta fish. This type of betta is characterized by its beautiful dark blue to black body with brilliant yellow fins, resulting in a very distinct, identifiable color combination. The Mustard Gas betta fish has a bright iridescent blue or green body and yellow-orange fins.

Varieties of This Betta Include the: -

  • Blue colored Mustard Halfmoon Betta- Blue is the most common color variety of this betta. Sky blue being the best color to look at, with a bright orange dorsal fin. They are known to be extremely hardy and are bred all over the world now.
  • Orange Mustard Halfmoon Betta- This is the rarest color variety of these bettas, and are also called "red halfmoons". These are more expensive than the blue ones, but their tails aren't as showy. But still possess a bright orange dorsal fin like other colors.
  • Black colored Mustard Halfmoon Betta- It's a black variety of halfmoon bettas, with bright orange dorsal fins. These fish are very hard to breed.
  • Green Mustard Gas Halfmoon Betta- This is a beautiful color variation between light and dark green. They have bright orange dorsal tails, but the coloration makes them look as if they do not possess one. These fish are very hard to breed as well, and are extremely expensive.
  • Dragonscale-The dragon scale is a one-of-a-kind variant of the mustard gas betta that has metallic sheeny scales. Blue fish are most often seen, although green ones can occasionally be found.


The first betta was bred in the United States in 1999 by Jude Al, a breeder. It took 13 years for Jude Al to grow his "pure" betta, according to him. The majority of these fish are currently bred by cross-breeding or imitation.


The average size is 2-2.5 inches and the maximum size is generally around three inches in length.


They have a lifespan of 3 to 4 years. However, these fish can live up to five years if well looked after.

Tail types

Bettas are renowned for their gorgeous flowing tails. Tail forms vary from one betta to the next. Mustard bettas are no exception. There are several tail types of mustard gas betta fish which are: -

Crowntail Betta - Another popular and common variety is the Crowntail betta. The fish's anal and dorsal fins have extra-long rays that make them resemble a crown, with spiky-looking tails like this.

Fullmoon - A fullmoon betta has a tail that is round in shape. It is also called a "half-moon" due to its crescent-like tail.

Halfmoon - The mustard gas halfmoon betta has a beautiful arched tail, resembling a crescent moon shape. This type of fin is very showy and elegant.

Delta Tail -This form is similar to the halfmoon tail, but is triangular in shape.

Fan Tail - The fan tail looks like a wide triangle and can really make your fish stand out in a tank full of other bettas. It's not as showy as the halfmoon and fullmoon tails, but still nice.

Swordtail - The swordtail has dorsal, anal and ventral fins that extend far from the body like a sword's blade.

Combtail - The combtail betta has an arched back with large upright fins on its dorsal side. This betta is known to be very hardy.

Double Tail - This type of betta is called a DT for short. The fish have an arched back and a large tail fin on each side. They're not very common in pet stores but can be found.

mustard gas betta fish 1

How Much Does a Mustard Gas Betta Fish Cost?

The typical cost of a mustard gas betta is between $5 and $20.

Typical Behavior & Temperament

The typical Mustard Gas halfmoon Betta is an extremely active, energetic fish that does best in big gallons of water or larger aquariums. Male betta splendens fight each other and should be kept alone; females can be kept in groups. They are sensitive to sudden changes in water pH or temperature.

How Did a Mustard Gas Betta Get Its Name?

A Black Mustard Gas Halfmoon betta is a high-grade coloration fish from the original longfin variety. This fish has a dark blue to black body with brilliant mustard yellow fins, resulting in a very distinct, identifiable color combination from which it takes its name.

Mustard Gas Betta Tank Condition

Mustard Gas betta fish care is relatively simple, because this hearty species can survive in a wide range of aquarium conditions. A single fish may be kept in a ten-gallon tank, while two individuals can be accommodated in a twenty-gallon tank or larger one.

They require warm aquarium water between 72- and 78-degrees Fahrenheit, but will do best with a heater to maintain a stable temperature between 76 and 80 degrees. The Mustard Gas Betta prefers a pH between 7 and 8, but can survive in a range from 6 to 9. They must be kept alone or as a mated pair, because males fight each other mercilessly, but females can be kept in small groups.

Tank Decor

Mustard gas bettas should be given a wide fish tank with a dark substrate and a place for them to hide, such as plants, driftwood, or rockwork. They will spend most of their time in the open water area, making them an attractive display fish.

However, they actively feed during dawn and dusk and enjoy having a small cave to retreat to at those times. It is very important to make sure that there are no objects with sharp or rough edges, because it may hurt your betta fish.

Mustard Gas Betta Tank Mates

The addition of a Mustard Gas betta to a fish bowl with other species can be risky. While not overly aggressive, this fish is known for its occasional bouts of fin-nipping and chasing, and it may bother some tankmates with more peaceful temperaments. It should ideally be kept in a community aquarium with fish that can tolerate its active nature, such as

  • Neon Tetra- The Neon Tetra is a very popular fish in the aquarium hobby because of its bright colors and peaceful temperament. These tetras are a good-sized schooling fish and will normally swim in the middle to upper regions of the aquarium.
  • White Cloud Mountain Minnow- The White Cloud Mountain Minnow has a peaceful temperament and will avoid conflict with most other fish. This minnow is shy by nature, so provide plenty of hiding places for it to feel secure in the aquarium environment.
  • Rainbow Shark- The Rainbow Shark is known for its peaceful demeanour and its overall hardy constitution; therefore, it makes an excellent tankmate for larger fish such as the Mustard Gas Betta.
  • Glowlight Tetra- The Glowlight Tetra is a small schooling fish that is very popular with beginning aquarists. These tetras are not picky about their tank mates, but they must be kept in small groups of at least six individuals
  • Tiger Barb- The Tiger Barb is a relatively peaceful fishes that can be kept with other fish, providing they are too large for it to eat. It prefers a pH level between 6 and 7 and can be kept in saltwater or freshwater.
  • Sterbai Corydoras- The Sterbai Corydoras is a peaceful South American fish that will swim in the middle to lower regions of the water bowls. It has a dark gray, almost black body and is covered with white spots. The fins are also decorated with large patches of white.
  • Cardinal Tetra- They are known to do well when in group of five or more in an aquarium with dim lighting and a soft, sandy substrate. They are mainly a nocturnal fish that will rest during the day and feed at night.
  • Silver Tip Tetra- The Silver tip Tetra is found in South America and is known for its peaceful temperament. It will generally school with other fish, but can also be kept in small groups or as a mated pair.
  • Ghost Shrimp- The Ghost Shrimp are very energetic and peaceful swimmers. They can be kept with other fish, providing they are too large for it to eat. This shrimp can also act as an effective cleaner for the tank because of its scavenging nature.
  • White Cloud Mountain Minnow- The White Cloud Mountain Minnow is very shy and is often used in community tanks with other types of fish. They can be kept with mustard gas bettas as long as they have plenty of room and the favourite types can be kept together, provided that there is a divider between them.
  • African Dwarf Frogs - African Dwarf Frogs are a popular species of aquarium fish, because they can live in both saltwater and freshwater. It is important to make sure the tank has plenty of hiding places for this species if it is added to an aquarium with a betta fish.
mustard gas betta tank

Are Mustard Gas Bettas Good Tank Mates?

The mustard gas betta fish will do well in a well planted tank without boisterous or fin-nipping tankmates. While it is friendly with a few bottom-dwelling species and some peaceful fish, males of this species can be very aggressive toward other fish in the middle and top of the water column. Females, however are known for being very passive.

Are Mustard Gas Betta Fish Suitable for Your Fish Tank?

These remarkable betta fish are a real catch. One of the loveliest features about these betta fish is their gorgeous hues and fins. Mustard gas bettas have an unusual name as well as a quirky personality.

 Small freshwater fish like this one are simple to maintain and can be cared for by both beginners and experienced aquarists. You only need a little effort if you want to keep these fish, and they will thrive in the right conditions.

If you're looking for a small-finned betta in your tank, you can consider Betta Macrostoma. This unique small bettas comes in a range of hues including red, orange, brown, and even yellow with black and white markings.


Since these betta fish are omnivorous, they require both protein and vegetation in their diet. meals rich in protein helps in the development of fins and colors. Also, good feeding habit stimulates their appetite.

What to Feed Mustard Gas Betta Fish?

Live Foods-Brine shrimp and tubifex worms are good sources of protein. They are also a good treat for this species.

Frozen Food-These betta fish can also eat frozen bloodworms and daphnia. These foods should be dye-free or treated with natural dyes.

Vegetables-Mustard gas bettas will readily consume various vegetables such as spinach, zucchini and peas. They can also eat green beans.

Protein Pellets-These betta fish will also accept specialty betta pellets, as well as flakes or freeze-dried foods. Good brands include HBH Betta Bites and Omega One Betta Buffet Pellets. If you want to provide a varied diet for your fish, it is a good idea to purchase a few types of food to see which one they appear to enjoy the most.

When to Feed?

Mustard gas bettas need to eat often and in small amounts. You should feed these fish about twice a day. This will depend on how many betta fish you plan to care for, as well as your budget and schedule. You can also adjust the frequency of feeding if your pet seems to be gaining too much weight or seems weak and thin.

How to Breed Mustard Gas Betta Fish?

These bettas are mostly crossbred, but they can also breed true with some species. Breeding mustard gas bettas is pretty straightforward, particularly if you already have experience keeping these fish. They can be bred in a 10-gallon or larger tank that has fine gravel, smooth pebbles or marbles for substrate.

This species requires low lighting and a few floating plants to provide shade during spawning. A heater may also be necessary to maintain the temperature within their preferred range of 75–83F. Your first step should be to keep one male and several females in a large tank where the water has been properly treated for breeding purposes. This will encourage your betta fish to begin building a nest. Once they are ready, the male will begin courting the female until she is ready to accept his advances.

Once mating has occurred, the female will release eggs, which the male will then catch in his mouth and hold until they are fertilized. He will continue to gather more eggs from the female until she is spent of her supply.

The male will then lay the fertilized eggs in a secure location, typically his bubble nest. The female bettas will need to be removed from the tank as soon as possible as there are chances of her eating the eggs.

The eggs will hatch in about two days, and the fry will become free swimming three to four days later. The male should be removed from the tank once the eggs reach this stage, as he will likely try to eat the fry.

Betta Fish fry

How Do I Care for My Fry?

They are very easy to care for. The fry will accept small live foods such as microworms or infusoria. You can also feed them commercial fry food for several weeks. However, it is a good idea to start them out on brine shrimp once they begin to show interest in eating. Make sure that the water parameters are set right with good filtration.

Common Diseases

Mustard bettas like any other fishes are prone to diseases that may come with time and negligence of the owner. It can be life threatening if not taken proper care of. The signs of diseases are visible when the fish start to lose their coloration and becomes lethargic, starts rubbing against plants and rocks in the tank and there is a cloudiness on the eyes. A few common diseases that might affect mustard gas bettas include:

  • Fungal Infections: Symptoms of fungal infections include redness and swelling in the fins. Treatment should be seen after antibiotics; Epsom salt bath and a high-quality diet is given.
  • Velvet: This is a common disease among the bettas and this might present itself as tiny white or yellow spots on the body, fins and gills. The advisable course is to quarantine the fish immediately and treat it with medication.
  • Swim Bladder Disorder: If your fish turns up at the surface of the water, it is because the swim bladder is not working properly. It can be due to constipation or a bacterial infection, in which case it has to be treated with antibiotics.
  • Dropsy: This disease manifests itself as a swelling of tissues that may end up rupturing and cutting off circulation to the body parts that are affected. The treatment for this disease is surgery.


Ammonia levels should be kept under control as they can cause disease such as fin rot. Salt baths can be an effective way of getting rid of ick and other diseases. Make sure you change the water regularly and keep salt levels at half a teaspoon per gallon.

Is It Unusual to Find a Mustard Gas Betta?

Yes! A direct descendant of those originally bred 20 years ago is an incredibly unusual find. The majority of the fish you see these days are produced from one male mustard gas betta and a different species' female.


Many pet owners enjoy keeping betta fish because they are peaceful and do not require a lot of maintenance. However, these fish still need to be cared for properly or else they will become sick or diseased. When caring for these fish, it is important to make sure that the water in their tanks has a proper ph. balance as well as a proper temperature.

Cleaning their tanks once a week is also important, and the water should be replaced with fresh tap water that has been dechlorinated. Other things to consider when caring for your betta fish are tank size, tank mates and feeding. These fish can live in small fish tank as long as they have places to hide like plants or rocks.

However, it is best to keep only one betta per tank if it does not have a divider. You can also house them with other peaceful species of fish. However, you should avoid boisterous species that may fin-nip your betta fish. Finally, make sure to feed these fish several times a day in small amounts since they are omnivores. So, if you are interested in fish keeping then these fish are a good choice.

Sarah Robertson

I am a passionate blogger who also happens to be a fish keeping enthusiast. Writing about my hobby is something that I absolutely love to do, and it's no secret that my chosen topic is always centered around fish keeping.

Sarah Robertson

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