Iridescent betta fish: What You Need To Know

Betta fish are a favorite among aquarists and beginner fish keepers alike. It’s not hard to see why. Many adore their flowing fins, vibrant colors, and striking iridescence. 

While bettas come in a variety of colors, iridescent bettas are usually blue or green in color. Their blue or green body scales shimmer under light, making them all the more beautiful. 

Did you know domestic bettas have more iridescence than wild bettas? This is due to a genetic mutation causing more vibrant and widespread iridescence.

Learn more about iridescent betta fish and the genetics behind their distinctive appearance.

What Is an Iridescent Betta?

iridescent betta appearance

An iridescent betta is any variety of betta fish featuring iridescent coloring or patterns. 

Iridescence is most common in wild betta species, including the following:

Wild betta fish with iridescent scales are usually turquoise or green in color. They also tend to have reddish fins and tails. 

Selectively bred bettas may also be steel blue or royal blue in color. 

This said, there are several pattern and color varieties of iridescent bettas. A few popular varieties include the following.

Bi-colored Bettas

These are betta fish with two colors: one solid body color and one solid tail/fin color. 

The iridescent colors are very common in bi-colored bettas. This variety is striking in appearance, with many color combination possibilities. 

Marble Bettas

Marble bettas have two or more colors throughout their bodies and tails/fins.

The color combinations are vast, but blue and green are the most common.

This iridescent betta variety is fun to look at and adds a pop of color to any room.

Butterfly Bettas

Butterfly bettas are gorgeous, featuring a solid body color and bi- or tri-color fins. 

It’s common for this variety to have a blue iridescent body. Part of the fins will usually be the same color as the body, with one or two other colors. Varieties with red or white fin tips are especially popular.

Metallic Bettas

There are many varieties of metallic bettas, including copper, pastel, and opaque. 

This type of iridescent betta has heavy iridescence at the top layer. It gives the betta’s scales a metallic appearance.

Green is an extremely common color for metallic bettas. Their fins may be any color, but red, green, and blue are most common.

Grizzle Bettas

This type of betta features fins of two different iridescent colors. Its body is usually light-colored.

Grizzle bettas are a favorite for their vibrant, flowing fins and elegant appearance. 

What causes iridescence in bettas?

Iridescent bettas have cells called iridocytes. These cells cause the shiny, glimmering color layer we know as iridescence.

It’s important to note: bettas have a few different color layers. The order of these layers varies between wild and captive bettas. 

Captive bettas:

  1. Iridescent
  2. Black
  3. Red
  4. Yellow

Wild bettas:

  1. Iridescent
  2. Red
  3. Black
  4. Yellow

In both cases, the iridescent layer is the first, topmost layer. This is why we’re able to see the iridescent sheen so clearly. 

Most wild betta varieties feature iridescence.

Yet they tend to have milder iridescence than bettas bred through selective breeding. In wild bettas, the iridocytes are of the “normal” type (sisi). 

Bettas with normal iridocytes tend to have iridescence primarily in their fins. Some have small dots or sections of iridescence throughout their body. 

Through selective breeding and genetic mutations, many bettas have developed stronger iridescence.

These bettas have iridocytes of the “mutated” type (SiSi). These bettas feature vibrant colors and more intense iridescence.

Are Iridescent Bettas Rare?

iridescent betta fish rarity

Iridescence is one of the most common patterns found in bettas. Since most betta fish varieties have some iridescence level, this betta pattern is not rare.

Most bettas you find at your local pet store or online will have at least some iridescence. 

Opt for captive bettas if you’re looking for one with strong iridescence. Due to a genetic mutation, these bettas have broader iridescent covering. 

Average Cost

Since there are several different iridescent betta types, prices vary. 

An iridescent betta can cost between $20 and $40 on average.

You might end up paying more for a betta if it meets one of these criteria: 

  • It’s a rare variety of betta: A few rare betta types include marbled, Cambodian, and double tail. These bettas cost more due to their rarity and special physical characteristics.
  • It’s larger or healthier than average: Healthy bettas will cost more than ill or weak ones. It’s important to ensure you pick a healthy betta, though, so a slightly higher price may be a good thing in this case!
  • It comes from a trusted, established vendor or breeder: Bettas from quality vendors or breeders may cost more. This is because the fish will be healthier, better bred, and higher-quality. 

We recommend shopping around for the best betta breeder or vendor in your area. This will help you get the best quality of betta at the best price. 

Breeding History

Betta fish are native to Southeast Asia, especially near Thailand, Indonesia, and Malaysia. They have been bred for centuries as fighting fish.

While wild bettas have mild iridescence, it’s more prominent in captive bettas. This is because of a genetic mutation arising from selective breeding.

The mutation allowed for more prominent and widespread iridescence in betta fish.

Iridescence Genetics 

There are three main iridescent colors: steel blue, royal blue, and turquoise.

Each color is possible because of the B1 gene, also called the iridescent gene. Crossing bettas of two different colors results in further color ratio variations. 

Here’s an overview of the genetics behind the most common colors. 

Turquoise/Green (BlBl)

To breed a turquoise betta, mate a turquoise betta with a turquoise betta.

Steel Blue (blbl)

To breed a steel blue betta fish, mate a steel blue with a steel blue. 

Royal Blue (Blbl)

Cross a steel blue betta with a turquoise betta to make a royal blue betta.

Neither the steel nor turquoise gene is dominant, so crossing them results in royal blue.

This is a phenomenon known as “intermediary dominance.”

And if you mate two royal blue bettas? You’ll get bettas with roughly this genetic makeup: 

  • 50% royal blue
  • 25% turquoise
  • 25% steel blue

Shining, Beautiful Betta

Iridescent betta fish are a beautiful variety to consider. These bettas have differing colorations but must feature a blue or green shade.

Most bettas you find in-store or online will feature some level of iridescence. But you’ll also find those with little to no iridescence, such as black or albino bettas. 

Armed with this knowledge, you’ll be able to tell which kind you want or how to breed them more effectively.

If you thought this was interesting, please share with your fellow betta lovers!

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Wesley Oaks has a background in web publishing and decided to combine his skillset with his enjoyment of betta fish. When he isn’t working behind the scenes for Betta Fish Bay, he’s homeschooling his kids and soaking up quality family time.

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