Full Moon Betta Fish Care | Everything You Need To Know

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By Linh Nguyen Updated on 13 Mar 2023

Bettas, or Siamese fighting fish, are known for their beautiful and vibrant colors and striking fins. One type of betta is the Full-Moon betta. This fish stands out from other bettas because it is a double-tailed fish, and the caudal fin is spread 180 degrees or more, giving it the appearance of two half moons when viewed from above. This characteristic makes it easily identifiable and a popular choice among aquarium hobbyists. It has also earned them the nicknames “Full Moon” (FM)  or “Doubletail Halfmoon" (DTHM) Betta. Not only do they look unique but they come in many different colors as well!

Though many aquarium hobbyists keep Full-Moon Bettas for their attractive features, there are still a few things to consider before buying one. These fish are known to be more aggressive than other types of betta, and they require special tank setup and care in order to maintain their health and well-being. In this blog post, we will discuss the basics of Full-Moon Bettas: how to properly set up their aquarium, how to care for them, what kind of food they should eat, and more!

We hope this blog post has been informative and helps you make an informed decision should you choose to get a betta. With the proper setup and care, these fish can live for up to three years, so choose your betta wisely and enjoy the beautiful colors and unique features of this amazing fish!

A full moon betta fish

A full moon betta fish

1. What is full moon betta fish?

A full moon betta is a double-tail betta that has the apical edge of the upper caudal lobe and the basal edge of the lower caudal lobe at an angle of 180 degrees or more. This distinct feature separates this particular species from other types and makes it instantly recognizable amongst aquarists.

This line betta was created through a selective breeding program between Halfmoons and double tails, thanks to its tendency to increase the dorsal fin width and fin size without damaging the Halfmoon's tail. For this reason, they are also known as Doubletail Halfmoons or DTHM.

This is a very welcome line in today's aquarium betta hobby. They also have the same rating as any other double-tailed betta.

Fullmoon Betta Fish Introduction Video

2. Compare with Halfmoon betta fish

To compare and distinguish between a full-moon betta and a half-moon betta, just look at their tails. Both have tails spread out 180 degrees or more. However, a full moon is a double tail while a Half-moon is a singletail.

Distinguishing Fullmoon betta fish from Halfmoon

Distinguishing Fullmoon betta fish from Halfmoon

3. How do you breed a full moon betta?

Fullmoon betta breeding is a delicate and time-consuming process that requires patience and dedication. In order to achieve the desired phenotype of fullmoon fins, breeders must carefully select their fish for several generations, gradually working towards their goal. This can be accomplished by pairing individuals with desirable traits such as wide tails and strong colors, then waiting to observe which offspring show potential before making further decisions. 

It's important to note that while Halfmoons and Doubletails are the most popular choices when creating Fullmoons, other breeds can also be used in combination or alone depending on personal preference. Additionally, breeders may choose to introduce a strain of one breed into another in order to 'reset' certain characteristics or increase the genetic variety of the Fullmoon strain.

When it comes to actually breeding the fish, there are many things to consider. The best environment for fullmoon betta breeding is one that mimics natural conditions as closely as possible. This means providing plenty of clean filtered water, nutritious food, and appropriate temperature levels. Additionally, in order to successfully incubate eggs during spawning, a separate tank should be used with low flow and no air bubbles. Finally, after selecting potential fry from eggs that hatch, it's important to monitor them carefully over time in order to make sure they grow into beautiful fullmoon bettas with wide fins and vibrant colors. With the right care and attention, breeders can create stunning specimens that will amaze aquarists for years to come.

You can read the article: Selecting The Best Parental Resources For Breeding Double-Tailed Betta Fish for more detailed information.

A red Fullmoon betta fish

A red Fullmoon betta fish

4. Fullmoon betta fish facts

Fullmoon bettas are easily recognizable by their signature round, double tail, and caudal fin. Their tails are lush and large, often reaching up to 180 degrees when flaring. The fins have a unique shape that resembles two half circles coming together at the bottom of the fish. Fullmoon bettas also typically display bright colors, ranging from reds, blues, greens, and purples to yellow or white. Their fins often have iridescent highlights that sparkle in the light and make them even more beautiful. Additionally, they tend to be quite hardy and resilient in the aquarium environment.

  1. Full moon bettas have bright white bodies with a red or orange coloration on their fins and tail. They are bred selectively to produce these unusual colors and patterns in captivity. 
  2. These fish can grow to be up to 3 inches in length when fully grown, making them slightly larger than the average betta species. 
  3. They should be kept in tanks of at least 3 gallons, as they like plenty of swimming room and warm temperatures (78 - 84 degrees Fahrenheit).
  4. With proper care, they can live up to 5 years in captivity!
  5. Full moon bettas prefer live or frozen food such as small crustaceans, worms, and insects.
  6. They prefer to inhabit shallow water with plenty of vegetation and a moderate current.
  7. These fish are not aggressive and can be kept with other peaceful tankmates such as guppies and dwarf corydoras. 
  8. They require frequent water changes to keep their environment clean, healthy, and free of toxins.
  9. They are particularly sensitive to changes in water conditions and should not be subjected to extreme or sudden shifts. They also do not tolerate poor water quality and must be monitored closely for signs of stress or disease. 

This is a quick recap of the facts about the full moon betta. Keep these tips in mind when caring for your fish, and they will reward you with many years of joy!


When you have mastered the basics of caring for your Full-Moon Betta, you will have a fish that is healthy, active, and an interesting addition to any aquarium. If you follow the guidelines set out in this blog post, your Betta will thrive and swim happily in their tank for years to come. Remember, keeping a healthy diet is just as important as clean and treated water; provide only the best nutrition they can get! Don't forget to let me know how your Full-Moon Betta is doing in the comments below – and if you have any questions or concerns, don't be afraid to reach out. Thank you for taking the time to read about these beautiful species, I hope your Full-Moon Betta brings joy into your life! Happy fish keeping!

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