YY
males were produced (i) by androgenesis from XY male parents; and (ii) by mitotic gynogenesis
from XY neofemale parents. Progeny testing of these androgenetic and gynogenetic males, and
gynogenetic females, showed that most families (i.e. sibling groups of males and in some cases
females) gave monosex progeny only, when individuals were crossed to XX fish (i.e. all-male
progeny from tested androgenetic or gynogenetic males; all-female progeny from tested gynogenetic
females).