Multiple Ray Branching in Bettas

I have been thinking of the factors in determining the expression of heavy branching in betta caudals (tails).

I have recently been experimenting with the 8-rays trait in HMPK bettas. Here's my male:

He is the son of a cross between a Red Dragon HMPK male from a friend and a Copper HMPK female from my line. It was a complete surprise that such a fish popped out. Well, he was worth experimenting on and try to produce more of him. From this outcross, I am guessing several factors that should be at play.

Here are my ideas:

1. [Phenotype] ray branching is not a good sign for determining 8-rays

2. A better dose of DT genes can help you out in producing 8-rays

Hypothesis 1: [Phenotype] ray branching is not a good sign for determining 8-rays

This male's mother is also spawned with a Green Red Bicolor HMPK from another friend. This male has 8-rays branching. One could easily assume that the gene is hard-wired already in the offspring. They might not show it but i thought the trait can be induced. Well, I crossed this male to a female. No 8-ray offspring was produced. In fact, there are even 2-ray offspring. I am quite disappointed.
Recently, I crossed 4-ray females back to him. I hope for better results.

Family line of cross in hypothesis 1:

Hypothesis 2: A better dose of DT genes can help you out in producing 8-rays
This 8-rays male is also crossed to a Copper HMPK half-sibling which is an F2. The cross was a Copper DTPK x Copper HMPK and it produced a sailfin male that I have never seen in my own fish room (DT-gene evdient). This cross with its half-sibling produced better and more rewarding results. Almost all the females are showing 4-ray branching at the minimum and one fish is actually turning out to be a rosetail. I can see that he'll be 8-rays at minimum but 16-rays is possible. However, there is no perfect fish. The more branching a fish has, the more X-factor fish he is. This super-branched fish is the spawn's runt.

Here is the 8-rays (or hopefully, 16-rays) from the 8-rays HMPK x Copper HMPK cross mentioned earlier

Family Line

I will see more of these crosses. Right now, I am growing out the backcross in Hypothesis 1. I am also planning several crosses with the fry.
A. F2 of the cross in Hypothesis 2
B. Cross the fish in Hypothesis 2 with the backcross of Hypothesis 1.
---I'm not sure with what to do with the F1 in Hypothesis 1 though. I'll keep some just in case.

UPDATE (05/22/2013):
Here is the best male in the backcross batch

UPDATE (10/23/2013)
A. F2 of the cross in Hypothesis 2
I see no rosetails in the rosetail's spawn!!!! OH NO!!! But, I'm assured the surviving fry have his genes.

B. Cross the fish in Hypothesis 2 with the backcross of Hypothesis 1
The backcross male featured above is crossed to a Green HMPK female. The female has 4-rays and is a sibling of the Copper Red Rosetail male. There are four survivors and they have average branching just like the F2 in Hypothesis 2.

Now, I plan on doing a cousin cross between Spawn A and Spawn B. I hope they produce some 8+ ray offspring. Here is the resulting effect:

We can see that the cross (a cousin cross) would be a really close (or inbred) one. The yellow boxes represent the Copper 8-rays HMPK. The blue boxes show that "3 out of 4 grandmothers" is the same female. Moreover, the green boxes represent the "root" female. She is the base for all the fish in this pedigree.


UPDATE (10/28/2013)
After moving some fish, I notice another backcross spawn (not the same spawn as the one with the featured male). There are three surviving fish: one copper, one platinum and one lace (AOC). They are slow growers so I'm trying to pump them to cross with other fish descended from the Copper 8-rays male.
Lately, I have seen a rosetail with late branching. This means that the rays only branch near the edge of the tail. I can see these survivors have some potential especially the platinum red. I am guessing the platinum is female and so is the copper.

UPDATE (11/03/2013)
Here is the Platinum Red female I was talking about in the previous post.

Here she is. The caudal is very promising. It shows some signs of heavy branching and possible rosetail. She is from a different backcross spawn. I am looking forward to crossing her to the offspring of the Copper Red Rosetail HMPK and an 8-ray HMPK I acquired from a friend.