Betta Splendon genetics?

I love genetics but can't find much about fish!
I was wondering if anybody could tell me which colours are dominant, recessive and co-dominant, same with fish tail type. I have a lovely blue green purple, shiny male with a tail somewhere between a delta and a comb. I would love to breed him to create crowntail of the same colour/ Is crowntail dominant?

Many thanks @JohnH.
Dr Myron Gordon (a geneticist and author of the best book on siamese fighters to date.....it was a 1950s book by the way) was certainly the person who inspired me in the very part of 1970s to get into siamese fighters and their genetics.

@Chelseasplendon95......... the genetics of siamese fighters is not always straightforward, but I see that as you mentioned the dominant, recessive and co-dominance then you may (??) have some understanding of genetics................that will be help.

Certainly Mendelian and non-Mendelian genetics are at play in siamese fighter genetics............and you can have multiple colours being dominant or acting as dominant (that is when the fun of non-Mendelian genetics kick in).

An additional bit that makes siamese fighter genetics fun is the fact that many are hybrids (inter-specific hybrids), and that the order of colour layers can change in some strains.
That later piece makes it interesting as masking of colours in important in fighter genetics.

You could have a fish that has a metallic blue dominant colour that is copper coloured but looks white............because of a white (opaque) masking. (just to wet your appetite)

In general, we need to consider the colour layers and what type of colours you have in those layers: some colours are structural (ie they are not colours and do not really exist as colours), and some colours are actual pigments.
Then you have the physical optical mixing of colours to contend with.

You have simple dominant, recessive, incomplete dominant, co-dominant alleles.....acting in different layers.
I mentioned masking effects above, but you can have moderating effects from lower layers.............much like we have in eye-colour where melanin can moderate "colours" of the iris.

You could, for example, have a fish that is expression a really super yellow colour.............but the melanin layer above that would block the yellow from vision.
Hence, you'd need a mutation where yellow is expressed and another where red, blue,and melanin are not expressed (and no top opaque layer as well).

Are you getting the picture?

But that makes everything very interesting.

Tails tend to be a bit easier..............but I really don't like some dominant tails such a double tails as they show poor choice of parents and bad breeding stock.

Also, when breeding for colour you need to take into account other biochemical problems that may come along with a certain colour/tail: eg I have found a number of biochemical and physical problems with certain colour strains that have been tough to rid eg rubbish fins and tryptophan metabolism problems with some opaque strains.

I will leave it there for the moment to allow you to come back with some specific questions rather than me write a complete thesis in a single thread

I did a talk on this at the ITFS a few years ago and was gonna hope to repeat it.............the talk was about breeding and line-breeding methods.

ian

Hopefully you do repeat it at a ITFS meeting in the future I would be very interested in that.

Regards
Craig

fishmad1234 wrote:

Hopefully you do repeat it at a ITFS meeting in the future I would be very interested in that.

Regards
Craig

I'd love to.

It was a pity I missed one of my other special topics of interest last week: killifish.
But work has to take priority.


@Chelseasplendons95............. here is a link to one of the discussions on genetics here

www.irishfishkeepers.com/forum/7-breedin...-babies?limitstart=0

ian

With having your self and Eric on this forum I don't think there is any need to ever Google a question about bettas people on here are absolutely blessed to have people like your selfs with so much knowledge on here



Regards
Craig

Hi Ian , would be good to learn a bit about betas at a meeting

Sorry for taking a while to reply, your reply is really long so there was a lot to take in after working. I'm more confused now than I was before asking! Hahaha

Genetics were my favorite topic in my agricultural science module in secondary school. I did punnet squares just for fun.

I was initially extremely confused but I just read it for the sixth time and realized it's similar to horse genetics. Horses have two colours, red and black, from there they have a huge variety of genes that effect the coat from patterning to the colour of their skin. Thank you very much.

If you ever have any other talks, I'd love to go.

Okay so basic questions first.
Which basic pigments are dominant? I'm guessing that blue and red are the very base pigments (just judging from the colours I see in pet shops). That yellow and purple are the results of a diluting gene?

Thank you for the response

Along with blue (iridescent) and red there is also a black layer but (Ian correct me if im wrong) is not as dominant as the other 2 but still does have a factor in the eventual colours

Yellow and orange bettas come from red stock and don't breed through as far as I know

A full proper purple betta hasn't been achieved yet. Any bettas you see with what looks purple colouring is just iridescent same as green

Eric

Oh @chelseaSplendons95............... you're gonna love this.

Siamese fighter genetics regarding colour are complex................so if you were confused from my post then things are looking good.

Considering a few alleles
- Spread iridescence over the body and fins is dominant.

- Opaque is dominant. (that is expression of an opaque layer on the upper layer). You can have a dominance of, say, opaque and spread iridescence [read my bit on the platinum whites in the link I gave].

- Butterfly fins (or other varigated fins) is dominant

- Extended Red is dominant. (red all over...and different tones of red at that)

- Loss of Red colour with age is dominant

- the "blue genes" give rise to incomplete dominance............these are interesting................
Let Bl = Green Iridescence allele and bl = metallic blue-green then when we join the 2 alleles we get
a) BlBl = Green (double dominant blue)
b) Blbl = Royal Blue (heterozygote blue)
c) blbl = steel blue (double recessive blue)

Yellow colour is located on the lowest colour layer..............so you need to have no expression of colours in layers above that.

ian

I didn't go into recessive alleles here, nor did I go into combinations of dominant alleles

Important recessive include:

- Cambodian (that is limited melanin)
- black (some are fatal genes)
- non-red...........this is a gene that removes red
- blonds = lowered melanin layer

I'll stop there...................

ian

Thank you very much. That makes much more sense now!
So due to incomplete dominance I'm guessing he carries blue and green, he is iridescent..... does the iridescence create the purple hue or is that another pigment?

He has patterning on his fins that I have never seen before but can't seem to photograph, almost like a snakeskin guppy!

The problem with the "blue" is that it is a structural colour in siamese fighters (and nearly all other fish)..............it is not a blue pigment....................it depends on light being reflected from it just like we get with blue eyes in humans.
Therefore the colour perceived depends on other factors such as incident light and nerve control.

Just stretching my memory, though, the only fish that I can think of at present that is coloured blue is the Mandarin (dragonet) fish (marine fish).............it has cyanophores and is not a structural blue as in siamese fighters.

ian

I'm confused all over again. haha

Purple is an interesting "colour" in that you may have an extended red with an overlay of blue iridescence......thus the actual lighting will play an important part of what apparent colour the fish will appear.

As you have a fish with a dominant or incomplete dominance, it is not easy to tell what alleles are behind that for defo..................but a bit of breeding may help reveal the truth.

Certainly breeding with a fish of recessive traits will help ascertain the genetics behind your fish.

ian

I have just seen your fish on a link on another thread...............that is blue, purple may be an artefact.

As I was saying structural colours are not really real (eg blue ion siamese fighters, but blues in Mandarin fish are blue ).

ian

Thank you so much I'll be getting photos under natural light tomorrow as the blue light seemed to drown everything out. You couldn't see his beautiful shine and colours. I'll keep a look out for a female with a similar colour and see if maybe I can figure out how to draw some purple out.

With structural colours, the colour depends very much on the lighting used to view it.

ian