Cauliflower Swordtails - Selecting and Genetics

[lewk]

Hello,

I recently saw a video of Cauliflower Swordtails and instantly fell in love. After some extensive searching, I was also able to locate a local source of them that will have a new batch available soon. 

My first question is fairly simple: What should I look for when selecting my initial stock of swordtails? On the surface, it feels like I just want to get the best looking, healthiest fish and pick the male with the best finnage and longest tail. This will be my first swordtail, though, so I don't know exactly which features are valued highest, or if there are some things that could indicate potential problems down the road. A concern that I'm having with this is the concept of an early maturing male - I don't want to choose the male that looks the best now if it's done growing and others will look better in time. 

The other question I have involves the Cauliflower gene. I do not know if the Cauliflower aspect, the ruffling of the dorsal, is tied to the Hi Fin gene or not. My understanding is that the Hi Fin displaying swordtails are all heterozygous (Hh) for the Hi Fin gene, as homozygous (HH) Hi Fins are not viable for some reason. I am curious if the (hh) low fin offspring carry the cauliflower gene, thus allowing a lowfin offspring to breed with Hi Fins (cauliflower or not) and produce cauliflower offspring. 

Any info is appreciated! 

[PineSong]

I’m currently in the process of raising swordtails for the first time myself. No experience with the cauliflower gene, so can’t help you there, but I did attend a talk at the ALA Triple Crown convention this year by the expert breeder Karl Trochu and he did stress the importance of keeping females away from all males until you have identified the best potential father. 
So far my oldest fry were born May 29 and none have a sword yet and no gonopodiums developing yet either. I am more interested in the color of mine than the sword length so I haven’t paid attention to estimated time to full sword development when I’ve watched videos or read about them but I’ll bet Karl Trochu gives that info somewhere.

[lewk]

On 9/5/2022 at 9:54 PM, PineSong said:

I’m currently in the process of raising swordtails for the first time myself. No experience with the cauliflower gene, so can’t help you there, but I did attend a talk at the ALA Triple Crown convention this year by the expert breeder Karl Trochu and he did stress the importance of keeping females away from all males until you have identified the best potential father. 
So far my oldest fry were born May 29 and none have a sword yet and no gonopodiums developing yet either. I am more interested in the color of mine than the sword length so I haven’t paid attention to estimated time to full sword development when I’ve watched videos or read about them but I’ll bet Karl Trochu gives that info somewhere.

Oh, good point. I'll have to look for information from him where I can. I did see him emphasize the importance of ensuring virgin females in the Members only video on YouTube. I still need to select my initial trio of fish from the supplier and I am not sure what to select for in that individual. They'll be about 90 days old. 

[gardenman]

When doing selective breeding you want an image in your mind of what your ideal fish will look like and how it will behave. Some cauliflower swordtails now have dorsal fins so high and heavy that the fish often have to sink to the bottom to rest as it takes a lot of effort to swim with all of that finnage. If your goal is to add even more finnage then you have to factor in the impact that might have on the fish's ability to swim. Guppy breeders got so intrigued by making larger and larger tails that they ended up with some fish who could barely swim. At ninety days you may find one or more of the females in your trio converting to being a male as they mature. Some swordtail males are very late developing. If you like the parent stock in general, I wouldn't fuss too much about the initial trio. You just want healthy fish as much as anything to start with. They'll have the genes you need to work with. Once they spawn and you have fry then you start selecting the ones you want to breed from there. You'll have a much larger selection to choose from. An initial spawn of a young female swordtail might only give you ten to twenty fry. Later spawns are more likely to give you 50-100 fry. You'll have a lot to choose from at that point. Whatever quality you're looking for will pop up at some point. You just have to identify it and continue to breed and cull to get more of that trait. 

[lewk]

On 9/6/2022 at 8:00 AM, gardenman said:

When doing selective breeding you want an image in your mind of what your ideal fish will look like and how it will behave. Some cauliflower swordtails now have dorsal fins so high and heavy that the fish often have to sink to the bottom to rest as it takes a lot of effort to swim with all of that finnage. If your goal is to add even more finnage then you have to factor in the impact that might have on the fish's ability to swim. Guppy breeders got so intrigued by making larger and larger tails that they ended up with some fish who could barely swim. At ninety days you may find one or more of the females in your trio converting to being a male as they mature. Some swordtail males are very late developing. If you like the parent stock in general, I wouldn't fuss too much about the initial trio. You just want healthy fish as much as anything to start with. They'll have the genes you need to work with. Once they spawn and you have fry then you start selecting the ones you want to breed from there. You'll have a much larger selection to choose from. An initial spawn of a young female swordtail might only give you ten to twenty fry. Later spawns are more likely to give you 50-100 fry. You'll have a lot to choose from at that point. Whatever quality you're looking for will pop up at some point. You just have to identify it and continue to breed and cull to get more of that trait. 

This all makes sense, thanks. I've seen what you're talking about with Guppies and other fish bred for finnage, and I definitely don't want that. Part of the appeal for Cauliflowers specifically for me was that I've seen many of the fish be active, and robust in spite of their magnificent dorsals.