Use this table in conjustion with our Betta Fish Genetics Predictor to determine what will come out of your spawn!
The single/double tail relationship is fortunately a very simple and predictable relationship. It is simply a dominance relationship – St is dominant over Dt. So StSt, StDt/DtSt are all single tail and DtDt is double tail. Simple enough eh?
Your Typical Betta, single caudal lobe
|Double Tail||Dt||Recessive||Double tail bettas have two distinct caudal lobes, and their dorsal fins are larger. Some Dts don’t have clean splits all the way down to the caudal peduncle, these are less desirable.|
A Bettas colors are broken into four basic layers: Yellow, Red, Black, and Blue (Officially called Green) layers. The Yellow layer has no known mutations so it is unaddressed here. Unfortunately right now I don’t have any reference pictures, but i would love to get some.
Less is known about tail genetics, and prediction is iffy at best. What is known is that a gene pair controls Short Fins (Sf) or Long Fins (Lf) (Plakat = sf, normal = lf), and that Long Fins is dominant. The shape genes only apply to the Long Fins bettas, and i’ve been told all Sf bettas are Vt.
|Veil Tail||Vt||Dominant||Your run of the mill petstore betta, breeders don’t like this tail shape|
|Delta Tail||X||Recessive||The tail is shaped like a fan, variably expressive in that the arc length of the tail varies. The abbreviation X comes from the need of a short abbrevation and other breeders using Vt/xx for this, due to the fact that delta tails arise from the complete lack of Vt genes|
|SuperDelta||T||Rcessive||Between Delta and Halfmoon lays super delta|
|Halfmoon||Hm||[Multiple Inheritance]||The Lovely Halfmoon tail shape, my favourite. This gene is variably expressive, most Hm * Hm spawns produce 5%-10% HMs, some very good strains get 10%-20%. The rest are delta tails but normally very close to being HM, which clearly shows multiple inheritance is involved.|
The (in)famous Comb trait – it seems to be an incomplete dominance relationship. With single allele being slight combing and double allele being strong combing (like that found in “Crown tails” (Super Delta + Strong Comb trait))
Once again, this is based upon my observations of the behaviors of the trait. I believe my presentation here is also a symplification, I think it may be a multiple-pair true-recessive trait (unlike halfmoon which is multi-pair and has a mix of dominant and recessive traits)
While right now I conjecture that it’s the rays that extend and not the webbing that doesn’t extend all the way, some of the fish I have seen support that it’s the webbing. If this is the case then this is independant of the trait that gives halfmoons extra webbing between rays so that they can reach 180 degree spread, because it is apparently possible to have atleast 170 degree spread Crown tails, I’ve seen them, the picture for Black Orchid above is of one that we own.
|Comb trait||Ct||Incomplete Dominance||The comb trait causes rays to extend past the webbing of the betta’s fins|
|Normal trait||Nt||Incomplete Dominance||The rays do not extend past the webbing of the betta’s fins|