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Blood red color in Bettas: a new pigment


Gaps in the genetic modeling of non-reds

The globally accepted model for red pigmentation in Bettas is ineffective to explain the issue that we will deal with here: the blood red pigment existing in the color of current Bettas.

In this article (and through our Course on Betta Genetics) we present the evidence that points to the existence of a new pigment. We will propose genetic modeling for practical purposes in betta breeders’ greenhouses.

See how interesting this can be in your betta strains!


A new pigment in bettas

The bettas we know in aquariums have very different colors and their distribution. Genes act on the fixation or instability of colors and the arrangement of colors in the phenotype, allowing it to change over the life of the betta – which is undesirable for breeders who seek stability in the improvement of their strains.

The domesticated bettas we know today are the result of the cross between different species of the Betta genus. In other words, they are fertile attractive hybrids, aesthetically and commercially.

In this sense, a new pigment has been attracting the attention of creators, which we will call BLOOD RED.


The current betta: a fertile hybrid and its genetic modeling

The selective breeding of bettas occurs with unprecedented beginnings. All visual characteristics (colors, color arrangements and formats) have Genetic Modeling, some of which are still from the 1960s, idealized by researcher Gene Lucas and others.

The domesticated betta, found in exhibitions is the result of the cross between Betta imbellis, Betta smaragdina, Betta mahachaiensis, Betta simorum and others, resulting in real living jewels.


The nature of the blood red line

This new type of red color can be seen in the first Red Dragon bettas that appeared on the world market. The photo below illustrates an example.

Note that the quality of the red tone in some Bettas Red Dragon (photo above) is different from that found in traditional red bettas – cherry reds.

According to the traditional model suggested by Gene Lucas, the betta is red (NrNr, Nrnr) or non-red (nrnr). That is, the two never occurring simultaneously.


Remember that in the nomenclature of genetics, everything related to recessivity uses a small letter, and when referring to dominance, the capital letter is used.

From this, there are the three genotypes of the initial modeling (1960s) that would define the presence of reds and yellows. See below:

Nr Nr – homozygous red (the two alleles are equal)
Nr nr – heterozygous red (the two alleles are different)
nr nr – non-red – would be the yellow ones

Gene Lucas was not concerned with classifying each of the different color arrangements from the traditional yellow ones. These began to emerge from the mating between heterozygous red Nrnr and yellow nrnr.

Pineapple and chocolate bicolors began to appear, and later, during the 1990s, orange and pink.

Both pink, orange, pineapples, chocolates, as well as the yellow ones will be included as nrnr in the model proposed by Gene Lucas.

See the photos shown below.

OBS: do not confuse the pink ones with the camboja bicolors, that have other genetic modeling.


Validation: would this new red really be a new pigment?

For the blood red coloring of the first Bettas Red Dragon there would be a new hypothesis: a different model from the traditional cherry red.

This was confirmed when this red began to appear in some bettas, along with the traditional yellow, chocolates and pineapples.

The Bettas Plakat phenotypes below have this characteristic:

Note that there are yellow and blood red colors appearing together in the betta in the images above. Therefore, there is a need to modify and expand the traditional model.


Questions arise to validate this modeling

a) How to define the colors of the new red and those of non-reds working together?

It becomes evident that a second pair of genes is needed for its modeling, together with the pair Nr / nr.

b) How can this be possible according to the universally accepted model for reds and non-reds?

Because they are fertile hybrids, their DNA has different genes for the blood red pigment compared to the red and non-red pigments, each coexisting in a specific locus.


Proposition of genetic modeling for the blood red gene in bettas

The traditional genes (Nr) and (nr) existing in the current modeling would continue to be responsible for the presence of both cherry red and non-red pigments.

Therefore, we will have another type of red pigment – blood red – represented by the Sg and sg alleles. Remember that they are alleles originating from a different species from Betta splendens, contributing to the formation of the fertile hybrid we know.

See this Orange infiltrated with blood red (the so-called Orange Dalmatian).

This betta will have the nrnr alleles (referring to the orange color), and a pair residing in the other Sg / sg locus, which may be SgSg, Sgsg or sgsg.

We will not go into the analysis and discussion of these new features and their practical modeling. If you want to know how to work with these practical models, join our Course on Betta Genetics, accessing our website.


Good luck with your Bettas!

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