The Truth About Delta Tail Bettas | Everything You Need To Know

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By Linh Nguyen Updated on 04 Mar 2023

The delta tail betta is a stunningly beautiful fish that is often referred to as the triangle-tailed fish. This tail form is the starting point for the Halfmoon tail, and when it’s done right, it creates a symmetrical shape with a wide angle between each side of the tail fin. This popular species of betta come in an array of colors from vibrant blues and purples to subtle greens and browns. 

Unfortunately, many sellers and even longtime aquarists have trouble distinguishing this line of fish from other single-tailed varieties. In this blog post, we’ll take a closer look at the delta-tailed betta and discuss what makes them unique so that you can be sure to make the correct purchase the next time you go shopping for a fish. We’ll also discuss some of their care requirements and behavior in order to better understand these beautiful creatures. 

By reading this blog post, you’ll have an even greater appreciation for the delta-tailed betta and be well-informed on how to properly care for one. So let’s dive into the fascinating world of this triangular-tailed species! 

Remember to follow us here on our blog page to stay up to date on the latest information about delta-tailed bettas and other aquarium topics!  Thank you for joining us today!  Happy Fish Keeping!

A beautiful delta tail betta

A beautiful delta tail betta

1. What is delta tail betta fish?

Delta tail betta fish is a popular and beautiful variety of the traditional singletail betta species. They are the starting tail form for the Halfmoon tail. The distinguishing feature of them is their caudal fin, which has triangular and symmetrical to each other throughout the body length. This form is similar to the fan tail but has a thicker (harder look) shape and an angular shape at the tip of the tail. When the angle of the tail is over 130 degrees it is considered to be a super delta tail, and when it reaches 180 degrees or more it is considered to be a Halfmoon!

Delta tail bettas come in many different colors from blue, red, black, and white to rarer colors such as purple or pink. They may not have quite the same level of color diversity as some other modern betta varieties like Halfmoons or Plakats, but they still make an attractive addition to any aquarium.

2. Distinguishing delta tail bettas

As mentioned above, Delta Tail (or DeT) bettas are often confused with other single-tail bettas. The term "Delta Tail" is often misused to refer to any single-tailed and non-HM betta. However, a true Delta Tail betta should have a straight tail edge like an HM, but it spreads into a smaller angle towards the back of the fish and does not straighten into a "D".

To make it easier to identify, I will guide you in identifying a delta-tailed Betta through the images below.

2.1. Delta tail vs super delta tail

An easy way to distinguish a delta betta from a super delta betta is by looking at the base of the tail. Delta betta tails have an angle of fewer than 130 degrees while super delta betta tails have an angle between 130 degrees and 180 degrees.

Distinguishing delta tail from super delta tail

Distinguishing delta tail from super delta tail

2.2. Delta tail vs Halfmoon

The difference between delta-tail bettas and Halfmoons is quite obvious when the angle of the delta-tail's tail is much smaller than the "D" shape of the Halfmoon.

Distinguishing delta tail from halfmoon

Distinguishing delta tail from halfmoon

2.3. Delta tail vs veil tail

People often confuse delta-tail bettas with veil-tail fish. However, you can tell them apart by their tail shape. The delta-tail fish has a triangular tail, while the veil-tail has a long and wavy tail, like a veil.

Distinguishing delta tail from veil tail

Distinguishing delta tail from veil tail

2.4. Delta tail vs round tail

You can also distinguish a delta tail from a round tail by the angle of the tail edge. A delta tail has a caudal edge that is perpendicular to the caudal ray, while a round tail has a rounded tail edge.

Distinguishing delta tail from round tail

Distinguishing delta tail from round tail

3. Delta tail betta fish facts

NameDelta Tail Betta Fish
Other namesTriangle-tailed betta fish
Size2 – 3 inch
Lifespan3 - 5 years
PersonalityEnergetic and quite friendly personality
Tank size2 - 5 gallons
HabitatNeed lots of plants and hiding places
Temperature74 and 79 degrees Fahrenheit (24-26 Celsius)
PH level6.5 - 7.5
The hardnessNot exceed 25 dGH
Nitrates15 - 20 ppm
Food & dietEat 1 to 2 times a day

3.1. Size

The average size of a delta tail betta is 2-3 inches in length from head to tail fin. Many male specimens reach 3-4 inches, whereas females tend to be smaller at 1-2 inches in length. Male deltas tend to have longer fins than females and also display more impressive coloration. Both sexes may show reds, blues, greens, or purples depending on the variety of betta.

The size of this betta line is determined by various factors including genetics, diet, and water quality. Regularly feeding them high-quality betta food helps to ensure that they are getting all the essential vitamins and minerals needed for optimal growth.

3.2. Lifespan

With proper care and a suitable living environment, the delta tail can live up to three years or more! Their lifespan is largely dependent on the quality of care they receive from their owners. Properly caring for your betta involves keeping them in a clean environment, providing them with the necessary food and nutrition, as well as giving them plenty of stimulation. This includes regular water changes as well as adding items such as plants, rocks, and driftwood to provide shelter and stimulation so they don’t become bored.

3.3. The Behavior

The delta tail betta is an intelligent and curious species of fish, and they can be trained to recognize their owners. They are typically very active, swimming around their tank with grace and ease.

Besides, these fish are also quite territorial; they don't get along well with each other or any other fish that may be living in the same tank. If two male fish are put together in the same aquarium, they will fight aggressively until one has established dominance over the other. They will also become aggressive when they feel threatened or if they sense a new fish entering their territory.

An old delta tail betta fish

An old delta tail betta fish

3.4. Female

When compared side by side, male delta tail bettas often have more vibrant colors, longer fins, and larger eyes than their female counterparts. In addition, females tend to be calmer, easier to care for, and better suited for living in multi-betta tanks. The male typically displays bolder behavior and may live longer and can show signs of intelligence when trained properly.

3.5. Breeding

Breeding this betta line can be a rewarding process. Delta tails have a stable genotype, meaning that consistent, predictable results can be achieved when crossing them with one another. When pairing two delta tails for breeding, the expectations are that almost 100% of the offspring will be a true delta tail; however, there is also potential for some of the fries to develop into super delta or Halfmoon varieties.

4. Delta tail Betta Care

4.1. Tank size

When it comes to tank size for keeping delta tail bettas, there is no one-size-fits-all answer. Bettas originate from tropical waters and prefer temperatures of around 78°F (25.5°C). In general, the bigger the tank, the more room they will have to swim, explore, and generally live a happier life. A good rule of thumb is that a single betta should be provided with at least 2 gallons (7.6 liters) of space, though larger tanks are always preferred as they provide more stability in water temperature and chemistry. If you’re considering housing multiple fish together in a single tank, it’s important to ensure that each has enough space to avoid potential conflict and stress.

4.2. Food & diet

Delta tail betta fish are omnivores in the wild and should be fed a varied diet for optimum health. A good diet for these fish includes a combination of high-quality, nutrient-rich pellets or flakes, as well as freeze-dried bloodworms, brine shrimp, tubifex worms, and other quality live foods. Omega 3 enriched foods are recommended to increase the overall health of your betta fish. 

They should only eat what they can consume within two minutes so that their water stays clean and free from uneaten food waste. Any leftovers should be removed from the tank quickly to prevent ammonia and nitrite levels from rising.

A Traditional Delta Tail Mustard Gas Betta Fish

A Traditional Delta Tail Mustard Gas Betta Fish

4.3. Water parameters

As with any other pet aquatic species, the water conditions they live in have an important impact on their health and well-being. When setting up a tank for delta tail betta fish, it’s important to make sure that the water parameters meet their needs. 

The ideal water temperature for delta tail bettas should be between 74 and 79 degrees Fahrenheit (24-26 Celsius). The pH level should range between 6.5 and 7.5; however, these fish can tolerate slightly higher or lower levels if needed. The general hardness of the water should not exceed 25 dGH (degrees of General Hardness). Finally, the water should contain moderate levels of nitrates and ammonia. 

In order to maintain optimal water parameters for delta tail bettas, regular partial water changes should be done, as well as proper filtration and aeration. Regular testing of the tank’s water parameters is also highly recommended.

4.4. Tank Mates

Delta tail bettas are peaceful fish that can make great additions to any community tank. They are best kept with other peaceful species, such as small tetras, rasboras, and danios. Avoid keeping them with larger or more aggressive species like cichlids.

When it comes to planting choices, they do well with hardy plants such as java fern and Anubis. These plants provide a natural hiding spot for the betta while also providing some oxygenation to the water, making it easier for him to breathe.

Keep in mind that your bettas may nibble on your aquarium’s greenery so you may want to opt for plastic or silk plants instead. Snails can be good tankmates for these bettas as they help keep the tank clean by consuming algae. Keep in mind, however, that larger snails could become a snack for your betta.

Finally, it’s best to avoid keeping them with other males as they can become aggressive toward each other and fight. So, when choosing tankmates for your betta, it’s important to choose wisely! With the right environment and compatible tankmates, you can provide your fish with a peaceful home where he can thrive.

4.5. Common possible diseases

Delta tail betta fish is one of the most popular aquarium species in the world, and like all other fish, they can be susceptible to diseases. The most common disease that this betta line contract is a bacterial infection known as columnar. This bacterial infection affects the skin and fins of the fish, causing grayish patches or sores along their body. Left untreated, it can lead to gill damage and even death. Other common health issues among these fish include fin rot, Ichthyophthirius (Ich), velvet disease, costia, Hexamita, or hole-in-the-head disease. All of these diseases are treatable with antibiotics if caught early enough, but prevention is always better than cure!

A pretty white delta tail betta fish

A pretty white delta tail betta fish


The Delta tail betta fish is truly a special surprise to the world. From their vibrant colors to their playful personalities, these creatures have something for everyone. While they may have some specific care requirements, with the knowledge and advice in this article you can properly care for your Delta betta with ease. If you’ve read this article and still need some help with setting up your tank or caring for your fish, please don’t hesitate to reach out for advice or ask follow-up questions. Delta bettas are delightful pets that bring beauty and joy into any home—just remember to give them all the love they deserve! As always, thank you so much for taking the time to read this article and if there was anything else that wasn't covered here then let me know in the comment below.

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