Mendel Squares for bettas?

[nowzem]

Can anyone tell me of a good resource for betta genetics? Most of the stuff I've seen is unreliable or not detailed. I want to know what traits are dominant. I want to know what I'll get when I breed x with x...or I want to be able to make my own Mendel squares to figure it out! I'm mainly interested in tail types and not so much colors (at least not yet!)

[DarkMoon17]

It is difficult to apply Mendalian genetics to bettas since many traits are on the same chromosome (which is something Mendal did not know when he made his thesis). However in general:
VT: Dominant (D)
Round Tail: D
Crowntail: CoDominant/Incomplete dominance: in other words, if you cross a CT with a VT/HM/SD you will get a VT/HM/SD with (not so nice) spikes
Single Tail: Semi-Dominant to Double Tail: when crossing a DT and ST you will get both tail types.
Double Tail: Recessive (R) you should not cross two DTs, only cross DT x ST
you will get some DT and some ST fry
HM and SD are basically recessive to VT and RT... HM and SD have more of a gradual inheritance pattern. If you cross SD x SD you will get a whole bunch of SDs. If you cross a SD and a HM you will get mostly SD and some HM. HM xHM will get you some HM and some SD...

Colors are MUCH more complicated. Here's a journal I wrote on it awhile back, it isn't perfect http://news.deviantart.com/article/139935/

[nowzem]

That so ROCKS! Thank you!
OK..next question.. what happens when you breed HMPK x HM (or any other for that matter)? I realize PK is more of a length and HM is more of a" spread" but I'm curious...will there be a mixture?

[indjo]

HM x PK = theoretically you should have more HM because long fins are dominant over short fin. But IME ...... it's a totally different story because not 100% of the fry will survive - so which genes actually survive to adult.

You will definitely get both; HMPK and HM plus a mix (HM with shorter fins, but not short enough to be called PK). You may also get a PK caudal but a rather large anal (undesired for shows). The "mixes" are usually a very small percentage.

[nowzem]

Thanks! That's exactly what I wanted to know! In the end, it doesn't really matter if I'm not planning to show them, I suppose! (As long as they are healthy and happy, too!)

[Dragonlady]

Someone needs to reinvent the tired old square in a 4-d model..

[nowzem]

I agree. It just doesn't work for bettas (or much else besides eye colors and pea flowers, LOL)!