Question on Swordtail Highfin

[Shenandoah Aquatics]

I am breeding Cauliflower Swordtails and some of the offspring are short fin. Will they carry the long-fin gene and potentially carry it on in future breeding? 

[Biotope Biologist]

The babies will not develop the fins until maturity. Depending on the breed you may see variation amongst females and males. I do not have specific experience with that breed. They are pretty though. 

[Shenandoah Aquatics]

You can see that some of the fry have short fins and some have long fin. They are around 3 months old now. The fry with long fin is very noticeable. 

[Fish Folk]

Hat tip to "Dan's Fish" YouTube Channel for info on these. 

Based on the chart below, the genetics looks like this:

Hh + hh = 50 / 50 Highfin and lowfin. 

Hh + Hh = 50 Highfin / 25 lowfin / 25 die-off (the HH genetic trait is unstable, and the fish will die)

 

[Biotope Biologist]

Well there you have it! That makes sense then that you have heterozygotes.

This would have been a way cooler experiment in a genetics class than boring snapdragons.

[Firestorm_1976]

On 3/23/2021 at 7:16 PM, Fish Folk said:

Hat tip to "Dan's Fish" YouTube Channel for info on these. 

Based on the chart below, the genetics looks like this:

Hh + hh = 50 / 50 Highfin and lowfin. 

Hh + Hh = 50 Highfin / 25 lowfin / 25 die-off (the HH genetic trait is unstable, and the fish will die)

 

Very interesting, and looks similar to hifin platies with HH being non-viable.

I have a question about lyretail swordtails for you, if I may. I have five lyretail "ladies" and no male yet. Is their lyretail-induced hifin is genetically similar to just the hifin? What would happen offspring-wise if they are bred with a regular bright-red (non-red-eye, non-hifin) male (the ladies are red eye, which I personally dislike). And what would happen if they are to be bred with a hifin red-eye (non-lyretail, since those are functionally sterile) male? 

Is breeding red eye + red eye runs chances of blindness or very poor eye sight in offspring?

Thanks so much in advance! 

On 3/23/2021 at 7:04 PM, Shenandoah Aquatics said:

I am breeding Cauliflower Swordtails and some of the offspring are short fin. Will they carry the long-fin gene and potentially carry it on in future breeding? 

Are you in the US? Once your juveniles start showing sex characteristics, is there a chance to get 1-2 hifin males from you? I am in Arizona.

[Fish Folk]

On 3/20/2024 at 12:57 PM, Firestorm_1976 said:

Very interesting, and looks similar to hifin platies with HH being non-viable.

I have a question about lyretail swordtails for you, if I may. I have five lyretail "ladies" and no male yet. Is their lyretail-induced hifin is genetically similar to just the hifin? What would happen offspring-wise if they are bred with a regular bright-red (non-red-eye, non-hifin) male (the ladies are red eye, which I personally dislike). And what would happen if they are to be bred with a hifin red-eye (non-lyretail, since those are functionally sterile) male? 

Is breeding red eye + red eye runs chances of blindness or very poor eye sight in offspring?

Thanks so much in advance! 

Are you in the US? Once your juveniles start showing sex characteristics, is there a chance to get 1-2 hifin males from you? I am in Arizona.

Genetics on multiple traits is very tricky to track. My approach is to separate desirables from undesirables, and breed until you lock in what you want. But it takes excellent breeding techniques, a bunch of tanks, a willingness to cull, and patience. Lots of patience.

I'm not patient enough to be a serious breeder 😅

[Firestorm_1976]

Thank you, Fish Folk! I only have one display tank (+ QT tank when I get new fish), so definitely not a breeder. But I wish to maintain a line of healthy next generation of swords, born and raised in my tank. With platies, the way I "cull" the "undesirables" is simply by rehoming them through a local hobbyist group :). That's why I am hesitant to get a red-eyed male, d/t concerns with impaired eye sight if bred albino to albino as the babies will not be for sale but for me to keep (at least those that I want, and I do not have a separate fry tank, so few make it to adulthood with many hungry mouthes swimming around 🙂