Fig. 1

Description of seven generations of natural matings and artificial insemination in experimental ponds and tanks and detection of female responders. Ponds are represented by ovals, and tanks by rectangles. The Oa species is denoted in blue and the On species in red. Purebred generations are denoted G1–G7. Lines between ovals (or rectangles) indicate parenthood and arrows denote physical relocation and re-mating of the same fish. Artificial inseminations or natural matings are indicated by black or green crosses, respectively. In generation G5, one pond and five tanks were used for mating progeny of G4 to produce the G6 generation and G6 hybrids. The numbers of known female responders in each tank are denoted by bold and italicized numerals. The unsuccessful tank mating is denoted by a rectangle covered by an “X”. A total of 46 tanks were used to mate 175 G6 female progeny to G6 males of both species: 23 tanks for On × Oa matings, and 23 for On × On matings, with 5 G6 females in each tank. The same 175 G6 Oa females were mated to both Oa and On males. The rate of detection of female responders is indicated in percentages (large red font) to the right of the year and generation annotation