In November 2025, I gave a talk to the Bucks Co. Aquarium Society in Pennsylvania. Great club! During their auction, a bag of pretty Endlers caught my eye. I purchased them and am now crossing them with my Rainbow guppies. Goal is to increase the fitness of my guppies. [Forthcoming article in ALA newsletter (American Livebearers Association) explains why.]
All the females I used for the outcrosses were non-virgins with stored sperm, so I had to carefully pick out progeny that were truly F1 hybrids. Good thing, because the first, early batches were mixed (hybrids and non-hybrids).
For the Endler male X female guppy cross (Photo), I picked out young female progeny with clear tails, a distinguishing feature of Endler females. So I was able to collect 5 nice virgin females from mating Endler males to a top Rainbow female.
For a reverse cross, I mated my best Rainbow males to Endler females (Photo). I identified hybrid females as Rainbow-sired by their darker, pigmented tails.
This is a long-term project. So far, I am pleased with the progress. When I began, I was not sure how to identify hybrid females. But now I have 5 very fine virgins from each of the 2 outcrosses. I plan to mate them to my best young Rainbow males.
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