Double Tail Betta Fish Facts - Everything You Need to Know

icon author linh nguyen

By Linh Nguyen Updated on 09 Feb 2023

Have you ever seen a double tail betta fish before? These unique, vibrant-hued creatures may look like your average everyday betta - but there is so much more to them than meets the eye! Double tail bettas are a rarer and special kind of Betta fish that require extra knowledge and care in order to thrive. From their fascinating anatomy to their expressive ways, these remarkable animals are full of surprises. In this blog post, we will explore all the amazing facts behind double tail betta fish – from diet requirements and natural habitats to common illnesses and how best to care for them. So if you’re ready for an unforgettable dive into the world of double tail bettas – let’s get started!

A beautiful doubletail betta fish

A beautiful doubletail betta fish

1. Origin and history

Doubletail betta fish have been a long-time object of fascination due to their unique appearance. Unlike the Wakin Goldfish and Jikin, which have two tails that lie side-by-side, the Doubletail betta has two distinct lobes or tails that sit one on top of the other. Additionally, these fish feature a longer dorsal fin and a shorter, fatter body than regular Singletail bettas - this helps them to better support their remarkable twin tails.

The doubletail phenotype is caused by a recessive gene, which when duplicated produces betta fish with two significantly larger tails and dorsal fins. However, the degree of split in the tails can vary greatly from one individual to another due to different genetic expressions. Some have perfectly balanced caudal lobes while others can have highly disproportionate caudal lobes.

The exact source of the doubletail mutation is uncertain. Some believe that the first known doubletail originated from Warren Young's fish room (a popular human breeder known as "Libby Betta"), while others suggest it appeared naturally in a betta shipment from Southeast Asia, and was kept by betta enthusiasts at the time.

The doubletail mutation is produced by a process called "ventralization," in which the dorsal fin differs from its normal form and becomes similar to the anal and lower caudal fins found at the bottom of single-tail fish. In other words, the mutant has replaced the upper portion of a fish with parts typically found on the lower area. Furthermore, it is not possible to find doubletail bettas possessing two ventral fins that protrude from their dorsal fin. It has been determined that ultraviolet irradiation can cause "abdominalization" in betta embryos; however, whether this directly relates to the emergence of wild doubletails remains unknown.

2. Double tail betta fish facts

Double tail betta fish are a truly beautiful species of Siamese fighting fish. They are characterized by their stunning fins, which feature two distinct and separate caudal fins that split into two separate tails, creating an elegant double-tailed shape. The scales of the double tail bettas come in a variety of bright and vibrant colors, including reds, blues, purples and yellows, making them quite the spectacle when swimming around in their tanks. In addition to their impressive physical appearance, they are also known for having highly active personalities with strong curiosity levels. Double tail bettas make great pet fish as they are relatively easy to care for and provide interesting entertainment while swimming around in their tanks. With proper care and maintenance, these magnificent creatures can live up to five years.

Let's take a look at the facts of double-tailed bettas in the table below:

NameDouble tail betta fish
Another nameDouble tail fighting fish, twin tail betta
Species NameBetta splendens
Lifespan2 to 3 years
Size2 to 3 inches
HabitatThe tank of at least 10 gallons with plenty of plants, 6.5 to 7.5 pH
Temperature74 to 82 degrees Fahrenheit
DietOmnivore that needs a variety of live foods
Activity LevelVery active swimmer
Care LevelModerate to advanced and need for high-quality water conditions
CompatibilityNot recommended for community aquariums unless kept with non-aggressive fish that prefer similar conditions

2.1. Name

Double tail betta fish, double tail fighting fish or twin tail betta are all names for the same species of fish, Betta Splendens. This popular aquarium fish is recognized by its bright colors and long flowing fins. The term “double tail” refers to the two separate caudal fin lobes that give this type of fish its distinctive look. Double tails have longer fin length than traditional single-tailed bettas, which gives them an almost ethereal appearance when they swim. They also come in a variety of colors and patterns ranging from solid hues to vibrant bi-colors and multi-color combinations. For those looking for a unique addition to their aquarium, double tails are sure to please!

2.2. Male

The male doubletail betta fish has two separate caudal fins, giving it the distinct "double tail" appearance. The fins are often long and flowing, in vibrant shades of red, blue, green, orange, white and more. The anal fin is usually shorter than the dorsal fin and can be seen as a fan shape on either side of the fish's body. The ventral fins are longer than the other fins and taper off near the end of their length. The tail itself is very thin with a pointy tip that makes it look almost spear-like when viewed from the side or below. All these features make the doubletail betta fish one of nature's most beautiful aquatic creatures.

2.3. Female

A female doubletail betta has a long, slim body that is usually brightly colored or patterned. The fins are generally shorter than those of the male and the tail has two lobes. Male doubletail bettas have longer fins and tails, with both dorsal and anal fins having multiple lobes. The males also tend to have a more intense coloration that often features bold reds, blues, greens and yellows. Both genders have an iridescent sheen on their bodies due to light reflecting off of the scales. Generally speaking, the females will be more subdued in comparison to males, though some may exhibit vivid colors as well. 

Overall, these fish are quite stunning creatures with unique markings and vibrant hues. With the doubletail betta, both sexes display an exquisite beauty that's sure to captivate any aquarist.

A female doubletail betta fish

A female doubletail betta fish

2.4. Size

A double tail betta is a type of fish that has two tails instead of the typical single-tailed bettas. They are usually quite small, with males typically reaching an average size of 1.5 to 2 inches and females staying slightly smaller at around 1.25 to 1.75 inches in length. Double tail bettas come in many vibrant colors, making them a beautiful addition to any aquarium or tank. These colorful fish can make wonderful pets for aquarists of all levels, as they are both hardy and visually striking!

2.5. Lifespan

A double tail betta has an average life span of three to five years if given proper care. They require a filtered tank with regular water changes and an appropriate diet for optimum health. Double tails are active fish, so they enjoy plenty of open space to swim around in their tanks. Because these fish can be territorial, it is important to provide plenty of hiding spaces within the tank. To protect them from disease, a stress coat should also be added when making water changes as well as periodic treatments with medications like aquarium salt or melafix to keep them healthy. With proper care and attention, double tail bettas can provide owners with many beautiful years of companionship.

2.6. Are double tail bettas aggressive?

A double-tail betta is an example of a peaceful fish. They generally prefer to spend their time in the middle or top levels of the aquarium, swimming around and observing their surroundings. They are known to be non-aggressive, making them an ideal choice for community tanks with other peaceful fish companions. Although they can become territorial, this behavior is rare and usually only occurs when two males are housed together. They also have amazing personalities and often enjoy interacting with their owners through the tank's glass. In general, these fish tend to be shy but curious, so they need plenty of hiding places and vegetation to feel safe.

While these fish may not be the most active, they have a lot of personalities and are sure to bring joy to any aquarist.

2.7. Habitat

A double-tail betta needs a habitat that provides the right balance of temperature, oxygen, and water quality. The ideal temperature range for this species is between 75°F and 80°F, so an aquarium heater should be used to maintain this range. Tanks should also have plenty of oxygenation through aeration or filtration; they may require more than non-bettas due to their labored breathing. Lastly, proper water quality must be maintained by performing regular partial water changes and using a high-quality filter or canister filter system. Ammonia, nitrite, and nitrate levels must stay at 0 ppm in order for your fish to thrive in its environment. With these conditions met, you will have a happy and healthy double-tail betta in your home.

2.8. Are double tail bettas rare?

Double-tailed bettas are not particularly rare, but they can be more expensive than regular single-tailed betta fish. The cost of double-tailed bettas is usually between $10 and $25, depending on the variety and quality. You can buy double-tailed bettas from many local pet stores or online retailers such as Aquatic Arts, Betta Fish Store, and LiveAquaria, among others. It’s best to research the store or vendor before you purchase a double-tailed betta to ensure the health of your new pet. Additionally, look for reputable sources that have good reviews from customers and guarantee healthy animals with proper care instructions included in their shipment. When buying a double-tailed betta, it’s also important to know the parentage of the fish and whether or not it’s a crossbreed. Knowing these details will help you determine if you are purchasing a double-tailed betta that is in good genetic health. Finally, make sure to look for signs of fin rot, parasites, fungus, or any other illnesses before committing to buying a double-tailed betta. Taking these precautions can help you find the perfect pet for your home!

3. Definition of a beautiful doubletail betta fish

We all have our preferences for how a good fish should look, but for the purpose of this article, I will be illustrating the ideal as defined by the IBC Judging Standards (Chapter 5, revised). 

Keep in mind that the ideal appearance of a quality betta, whether single- or double-tail, is a full circle with no open spaces between the three unpaired fins.

The base of the dorsal fin of a double-tail betta is expected to be considerably broader than that found in the singletail. The double-tail dorsal is, ideally, the mirror image of the anal fin in keeping with the concept of symmetry.

Doubletail bettas may have a deeper (top to bottom) body than single-tailed bettas. The thicker body is acceptable, as long as it contributes to the support of the larger finnage.

They should have caudal rays evenly distributed above and below the centerline of the fish. Proportionate volume is ideal as opposed to length. The volume of the upper and lower caudal should be equal and equally distributed above and below the centerline. The two caudals may overlap but should be separated all the way to the caudal peduncle. A half circle is ideal for the overall shape of the two caudal fins.

Doubletail bettas are expected to differ in several ways from the singletail:

  1. Possess two distinct 'tails' or caudal lobes instead of one, with complete separation to the base of the caudal peduncle.
  2. Possess a wider caudal peduncle to support the double lobes.
  3. Possess a larger dorsal fin, nearly the size of the anal fin.
  4. Their bodies are usually more 'chunky' and often a bit shorter.
  5. Bends in the caudal peduncle are expressed to a varying degree in almost all double-tail bettas. These are more easily noticed when viewing the fish from above. Easily seen bends should be faulted; if the bend is not excessive when viewed from above, the fish should not be penalized.
A dumbo ear double tail betta

A dumbo ear double tail betta

Double tails are docked points for not conforming to the articulated standard. How much they are penalized is based on the severity of the fault.

Body Faults:

  • Doubletail body too short or stout (slight fault)
  • Doubletail caudal peduncle bump or bend very noticeable (major fault)

Dorsal Faults: 

  • The double-tail dorsal is slightly more narrow than the anal (minor fault)
  • Doubletail dorsal has a few short rays at the front edge, not matched on anal (minor fault)
  • The double-tail dorsal is much more narrow than the anal (major fault)

Caudal Faults:

  • Doubletail caudal lobes are full, but separation is not quite complete -- separation is still greater than 3/4 (slight fault)
  • Doubletail caudal lobes are slightly mismatched (minor fault)
  • Doubletail caudal lobes separation between 1/2 and 3/4 (minor fault)
  • Doubletail caudal lobes are considerably mismatched in volume or shape (major fault)
  • Doubletail caudal lobes matched, but narrow (major fault)
  • Doubletail caudal lobes separation 1/2 or less (major fault)
  • Doubletail caudal lobes are mismatched and narrow (severe fault)

Double tail betta fish are a unique and popular variety of betta that have become increasingly popular among aquarists. Although all double tail bettas share a common trait - two distinct tails - they can vary greatly in terms of their body shape, coloration and finnage. With many variations in color, fin shape, and other physical characteristics, double tails offer an exciting range of aesthetic choices for those looking to keep bettas as pets or show them in competitions. Common varieties include the Halfmoon Double Tail, Plakat Double Tail, Crowntail Double Tail, Dumbo Ear Double Tail, Mustard Gas Double Tail and Super Delta Double Tail. Whether you're looking for an attractive showpiece or a hardy companion for your tank, you can be sure to find a double tail betta that suits your needs.

Take a look at the article: A Summary of the most beautiful doubletail bettas today, with more pictures and details.

5. Care 

Proper fish care not only helps the fish stay healthy but also grow quickly. You can play or trade to increase your income. One person will have a different way of raising betta doubletail, but sorry if you ignore the farming experience below.

5.1. Selection of betta doubletails

This is an issue that you need to pay attention to before raising. Choosing a healthy doubletail betta will help you become more leisurely and easier in the care process. Absolutely, you should not choose doubletail betta fish with signs of illness or abnormalities.

5.2. Food

Betta doubletail is a fairly omnivorous fish, so choosing food is not too difficult. You can choose prepackaged dry pellets or larvae, which are also their "favorites". However, the amount of food should be moderate; if too much is given, they will not be able to eat it all, polluting the water and easily killing the fish.

5.3. Maintain the right pH

For doubletail bettas, you should maintain a pH around 7 to 7.5 for them to grow well. This fish is also quite fussy, so you should fill about 2/3 of the tank with water; do not fill it too full. However, in some cases, the slight difference in pH does not affect the fish too much.

5.4. Treat the chlorine level of the water before raising betta doubletail

Before proceeding to raise a Betta doubletail, you need to thoroughly treat the chlorine in the water. You should expose the water to the sun for about 8-10 hours to remove the chlorine. If possible, you can also invest in a dechlorinator to make the process of taking care of your fish more convenient.

For the full scoop on caring for betta fish, be sure to check out this comprehensive article!

A beautiful halfmoon doubletail betta fish

6. Breeding

Breeding doubletails can be tricky, because mutations tend to cause spinal problems and deformities. Doubletail x doubletail matings will produce 100% doubletails, but these pairs also produce higher levels of scoliosis and other defects.

A usual way to breed bettas is to have a doubletail (DT) breeder with a singletail (ST). This limits the number of fry (baby fish) with spine problems and makes the dorsal fin longer. The first time you breed a DT with a ST, all of the fry will be ST. But some of them will carry the DT gene. This is shown by ST/dt. If you have two ST/dt bettas breed, about 25% of their fry will be DT.

The common practice today among ornamental betta breeders is to use Double Tail (DT) to improve their Single Tail (ST) lines by increasing fin size and dorsal fin width. This can be accomplished in the First Generation (F1), but selective breeding can be extended so that the ST betta has a dorsal fin nearly as wide as that of the DT!

A new and promising development is the HM DT, with its plump, stacked caudal lobes that can extend up to 180 degrees or more. Indeed, this combined with the symmetrical proportions of the dorsal and anal fins makes for an impressive betta!

Please see the article "Scattered About Breeding Double-Tail Betta" for more detailed instructions.


Bettas have been fascinating people for many years and their popularity has only grown in recent decades. The double tail betta is a relatively new variation of this fish that has quickly become a favorite among breeders and hobbyists alike. These fish are known for their stunning beauty and graceful swimming habits. While they may be delicate, with proper care double tail bettas can make wonderful pets. If you're thinking of adding one of thesefish to your home aquarium, be sure to do your research to ensure you can provide them with the best possible care. Do you have a double tail betta? What do you love about them? Let me know in the comments below!


1. Siamese fighting fish. (2023, February 1). In Wikipedia.

2. IBC Standards: 2009-2010 | Betta Breeding Forum.

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