I wanted to come back to this guppy again. The photos I took a few weeks ago were “ok” but I wanted to try and get some better shots. His pale yellow “high dorsal” fin continues to develop. When I posted photos of him on July 15, I had probably placed him in a breeding group a day or two before. On about August 7 or so, to my surprise, I looked in this tank and saw about 30 fry. These dates could be off 1-3 days, so it’s not an exact science around here. To my knowledge, those females haven’t been around any other males. Then again today, I noticed maybe 5 new fry in this tank. I’ll have to wait a few weeks to confirm “who’s their daddy.” But my hope is that I’ll get a good line of these high dorsals going.


SLIDESHOW:
Alan Bias emailed me about this “crossover” event. If I’m understanding what a crossover is, it’s a shuffling of the genetic/DNA deck. So it happens before your male/female cross, in the DNA of one fish, rather than a shuffle of DNA between a male and female guppy. This gives you a random, totally unexpected outcome which isn’t considered a mutation.
Regarding the fish above, Alan says: Yes, they basically are a Vienna w/o swords and clear roundtail from female X-link. He sent 5 photos to show examples from his fishroom.





Lower 5 photos are courtesy Alan Bias. Click here to read more about crossover events.
Terry, Looks to be a crossover event. Lost his Y-link LS. Occurs about 1/2 dozen or less times a year in my stocks.
My problem is always dorsal. How to develop it?
You’ll need to make a cross with another type of fish, one that has a nice dorsal. Once you’ve successfully gotten at least one male with a good dorsal, then he becomes your breeder male x only virgin females. Then you keep pulling out the males with the best dorsals. In some lines the dorsal quickly degrades over generations, no matter what you do, and there’s nothing you can really do except start over with better fish.