Repeatability of female preferences in a unisexual–bisexual mating system

Background: A gynogenetic species is a hybrid species in which females must mate with males of their parental species to initiate egg development, but inheritance is strictly maternal. Question: Is the mating preference of an all-female, gynogenetic fish and its parental species repeatable? Organisms: The Amazon molly, Poecilia formosa, is a livebearing gynogenetic fish of hybrid origin. Its parental species are P. latipinna (paternal) and P. mexicana (maternal). Methods: We examined and compared the repeatability in preferences of P. formosa and female P. latipinna for larger vs. smaller P. latipinna males. We also examined the repeatability of female P. mexicana preference for large male P. mexicana. Repeatability relates variation within individuals to the variation between individuals. We related measures of consistency to individual preferences to examine whether female preferences were unanimous. Conclusions: Females of all three species showed population-level mean preferences for larger males. Repeatability of the preference was low for Amazon mollies even though they are a clonal species. The maternal parental species, P. mexicana, also showed low repeatability but females of P. latipinna showed high repeatability in preference for large males, but their preferences were not unanimous.