Figure 3. The mating scheme. A female of the longer-living species N. kadleci was mated to a male of the short-lived species N. furzeri GRZ strain, resulting into 35 F1 individuals. Sibling mating in 13 families of the F1 gave rise to 364 F2 fish. Of these, 293 (81%) were successfully scored for phenotypes and genotyped at 16 weeks of age.