Returning fish to the shed now that cold weather approaches, this trio of Austrolebias reicherti (Paso del Dragon) appears. They are about eight months old. For a while, I had a line from the same location where the males had a more pronounced blue hue. We managed to karyotype one of them and it turned out to be a triploid. Whether that was the cause of the colour difference we observed or not could be answered by karyotyping a bunch of wild-caught fish with colour differences. Karyotyping can be done by fin-clipping and a recapture where the regenerating fin is sampled, no fish would have to be sacrificed for this test.