Hi-Fin swordtail pairs contain only one fish with Hi-Fin. The other will be Standard. In double dose, Hi-Fin is a lethal gene, so it's always best to cross a Hi-Fin with a Standard.
The swordtail fish that we ship are between 3 and 8 months old.
We are three years into this project. The goal was to increase size and vigor in domestic swordtail fish. (see project outline in our Blog). We crossed 2 wild Xiphophorus species into a domestic line and then separated the offspring into various strains by color. We then selectively bred for size and traits that we like and have been amazed at the size we are obtaining at this stage. By far the largest adult swordtail fish we've ever seen - simply magnificent fish. These fish may carry other genes, like hi-fin, various albino combinations, patterns like Koi, Neon, Green, White and maybe even others, so getting a few varieties in the offspring is common.
The Tuxedo swordtail type was developed from both wild fish and Red Alpha swordtail strains. The color is orange, not red, though some of the offspring will be more red than others, so you can select for that. Video showing some of the Tuxedo swordtail strain below:
Below video is example of swordtails and angelfish getting along fine together. Is is never any interaction between the two.