Notes on pet store bettas:

  • It is best to buy fish of known genetics from established breeders
  • Most 'pet store' bettas are 'mutts' and will throw random colors
  • Don"t work with pet store lines if you want to show your fry--they"re of a non-showable type called the veiltail.
  • Many pet store males are too old to breed well, females are usually younger.
  • That being said, if you know your stuff, you can get some good finds at pet stores.
  • If you're just getting started, pet store fish are good because they don"t set you back big bucks.
  • In all honesty, I"ve never bred anything BUT pet store bettas. And it"s still a blast and I still get neat stuff.

  • On Genetics:
  • the general rule of thumb is that if you breed two solid color or two-color fish that look alike you"ll get mostly the same thing.
  • For marble fish and patterned fish, all bets are off. Marble pairs throw marble fish, solid-colors, bi-colors, and just plain randomness. That"s of course because this is a mutation.
  • There are very few instances where betta genetics fail to follow standard punnett square genetic layouts. Keep this in mind and fill out the boxes before crossing.
  • Only with really recessive genes exhibited can you be sure an unknown betta carries the mutation fully. A blue fish (dominant) can carry a white gene underneath. A white fish has to have both white genes. Most pet store fish are blue and red, so their genes are unknown.

    Betta coloring goes something like this, for solids:

    If you were viewing a slice of betta skin through a microscope you'd see the pigments stacked atop each other like so:

    ---iridescent (blue/green) layer---
    ---red layer-----------------------
    ---black layer---------------------
    ---yellow layer-------------------- **

    ** This layer is so weak it isn't usually factored in. the Yellow fish for sale come from a mutation of the red layer.
    Keep in mind here that if any gene for a `higher' layer exists, the fish will exhibit that color even though they may carry `lower' colors. To display other layers, the higher layers must be bred out. (This has been done. Don't bother, it's generations of work. Start from the color you like.)

    From these basic layers:
  • iridescent can carry red or black recessively
  • red can carry black
  • black is "the end" and must have both genes to display.

    Iridescent have an odd quality--they don"t always breed visually "true". There are three shades of iridescent.
  • Turquoise (sometimes called green) T
  • Royal blue or blue B
  • gunmetal or steel blue G

    These have an incomplete dominance with each other. The royal blue exhibits when the fish carries one turquoise gene and one gunmetal gene. If a fish shows royal blue, you know it has one turquoise and one gunmetal gene. However, if a fish shows turquoise or gunmetal, it may have only one iridescent gene and a "hidden" red, black, or Cambodian gene. (Hidden Cambodian genes are the most common.)

  • TxT cross yields all T fish
  • GxG is all G
  • But a BxB cross gives 25% T, 25% G, and 50% B
  • A TxG cross gives 100% B
  • TxB is 50% each of T and B
  • GxB is 50% of G and B

  • Reds:

    Reds are the easy ones. What you see in stores are called extended reds—their whole bodies are red, not just the fins. Wild type reds have brown bodies and red fins. Extended red is dominant over wild red. Cross two reds and nearly always you come away with 100% reds.


    Blacks are tricky. There are two strains of black. Melano and lace or “fertile” blacks. The problem with the melano, the old strain of black, is somehow ALL the females are sterile. The males must be crossed with a turquoise or gunmetal female that carries black in her makeup. This of course yields only 50% blacks per spawn, somewhat of an unrewarding percentage. The fertile strains (rarer and more costly) breed 100% true.

    BE CAREFUL buying blacks. If you buy a pair (from a breeder, or online) and they advertise a pair, be sure it’s labeled as a fertile strain, or that it says the female is a carrier exhibiting an iridescent. Many folks find themselves cheated when their prize pair lays nothing but dead eggs time and time again. If you buy a pet store pair, assume they are melano.


    Yellows actually have nothing to do with the old yellow color layer and are a mutation of the extended red gene mentioned above. They are often called “non-red” yellows because they display no red anywhere. They breed nearly 100% true, with an occasional mutation. Yellows do tend to be more fragile than most, so not necessarily a good pair to start with.


    These are white-bodied fish with colorful fins. Red fins are the most common. They will breed true as to body color 100% of the time. If you are breeding the rarer iridescent Cambodians (blue or green fins) remember the rules for iridescent dominance listed above.


    Arising form several strains mentioned, starting with Cambodian and yellow and a handful of chance mutations, we arrive at white bettas. They are not albino, just true whites.

    There is argument about the nomenclature of these fish. They are called in turn pastel, opaque, super-white and the like. It’s basically the same set of genes and same principles apply.

    Common terminology has fish with pinker bodies and more shine to them (usually blue or green dusted on top for a pearl-like look) as “pastels” and fish of a darker, more solid, matte white as the true opaques.

    These are some of the rarest fish around currently, and are quite sought after. Many white strains are more fragile than other betta strains.

    WxW yields a whole spawn of white fish, BUT few of them will be perfect. Because they are still unstable strains, many will have flaws like faint red washes in the fins (these are near impossible to get out, even generations in), tiny specks of color on the bodies, or fins that are part opaque and part clear. You’ll get a spawn of beautiful fish your friends (and maybe pet store) will gladly take off your hands, but you may get one show/breeder quality fish out of every 50 fry.

    Patterned bettas:

    The basic colors breed true, but like whites, you only get a handful of perfect fish from an entire spawn.

    Marbles again throw just about anything that their colors will let them.

    Butterflies—where the fin where it touches the body is one color and a different one at the end—breed ‘true’ but very few of the spawn will have a perfect pattern. The (admittedly awful) drawing below shows how a true butterfly should be—clean color separation following perfectly the shape of the fins. Many fish will exhibit it perfectly on one fin or the tail, but not all three. A “true butterfly” has the pattern on all three fins.

    |~~~~~~~\       \
    |  red   | clear |
    |~~~~~~~/       / 


    Fin dominance is 100% true as well.

    There are many kinds of tails, some rarer than others. Breeders are working to insert them into all color lines, a daunting task to be sure. But if you can find a pair with the tails you want, they should breed true for you.

    doubletails are exactly what they sound like. They are any betta of any finnage type or coloration that literally have two tails atop each other across the lateral line. This is a wild-type mutation that has arisen in captivity time and time again but has also been seen in wild-caught pairs. They breed 100% true, but keep a lookout for fish with a bad split. The tails should separate all the way down to the body, and should have roughly the same number of rays on each lobe.

    Veiltail, ‘pet store’ tails, droop like scarves. If you were to extend the fish’s lateral line, the tail would not be symmetrical about it. This tail is not showable and not desirable anymore except for pets.

    Delta tails, which have sprung up to replace the veiltail, just means a symmetrical tail over the lateral line. They fan out in a rough triangle, much like an overhead view of a river delta. The tails are usually stronger and less droopy than the veils.

    A subset of the delta is the “half-moon”. This is a delta tail with a tail so large that it is a full 180 degrees when flared. These are very rare and usually only one or two a generation arise. “Half-suns” are the result of crowntail/halfmoon genes, with a full 180 spread and the extended rays.

    combtail is where each single ray extends slightly behind the fin membrane, creating a scalloped look. Also going out of fashion. (bad art to follow displays what the edges of the fin look like.

    FROM the combtail, however, evolved the crowntail. The rays—which usually branch at least once and are stiffer, present a look like a circlet or crown. The rays extend further from the membrane than with a crowntail. This is one of the most ‘in’ fins right now. Breeders are working on ‘triple’ and ‘quadruple’ ray, which is when that many branches are exiting together before the bit of membrane. With more rays, there evolve smaller scallops between ray pairs.
    Standard: ||__||__||__||
    quadruple: ||_||___||_||___||_||___||_||

    Unfortunately, my sources are lost to the years. This is what I remember from many books and webpages when I first researched this some six years ago. The data is widely available but this particular node is from memory, working at a fish store, and my own experience.

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