Do Female Western Mosquitofish,Gambusia affinis,Prefer Ornaments That Males Lack?

Abstract

Some species in the family Poeciliidae are known for extravagant male ornaments and courtship behavior (e.g., guppies), but the majority of poeciliids are characterized by coercive male copulation attempts that seem to circumvent female choice. In some lineages with male ornaments, female sensory bias may have preceded the evolution of corresponding male signals. We examined female preferences for colorful ornaments in Western mosquitofish, Gambusia affinis, in which males lack ornamentation and reproduce primarily through coercive mating attempts. We found that females exhibited a positional affinity for males that were artificially ornamented with blue coloration over males that had been treated with a transparent ornament. Females exhibited the opposite effect for males treated with red ornaments. In contrast, focal females did not exhibit behavioral discrimination between two live stimulus females or two models (silver fishing lures) with blue vs. transparent ornaments. This suggests a sexual context for female discrimination between males based on ornament color and whether an ornament was present. Because tribe Gambusiini is the basal branch of family Poeciliidae, the results of this study are consistent with the hypothesis that female responsiveness to male coloration is the ancestral poeciliid character state.

Personality differentially affects individual mate choice decisions in female and male Western mosquitofish (Gambusia affinis)

“…Even though females’ motivation to mate may decrease when fish are maintained in mixed-sex groups compared with virgins or females that had been isolated from mating partners for some time (e.g., several weeks [ 79 , 80 ], rearing or maintenance conditions do not necessarily affect individuals’ preferences for phenotypic traits of potential mating partners. Thus, studies on mate choice in mosquitofish widely used focal fish originating from mixed-sex tanks [ 36 , 81 – 83 ]. Aquaria were well equipped with plants, twigs and stones.…”

Reproductive Mode and Conflict Shape the Evolution of Male Attributes and Rate of Speciation in the Fish Family Poeciliidae

“…However, these studies quantified only copulations, not the siring of offspring, and both studies focused on species without courtship or male ornamentation. A number of additional studies have examined female preferences in species without courtship (McPeek, 1992;Basolo, 1998;Bisazza and Pilastro, 2000;MacLaren and Rowland, 2006;Casner et al, 2016). In nearly every case, females prefer a larger, more ornamented male, even when that male is not the same species as the female (Basolo, 1998).…”

Phylogenetic analysis and ontogenetic changes in the cone opsins of the western mosquitofish (Gambusia affinis)

“…To date, research has only demonstrated that the western mosquitofish possesses all four phylogenetic classes of cone opsin genes, including two sws2 genes ( sws2a and sws2b ), but exactly how many cone opsins it has remains uncertain [ 32 ]. Moreover, previous studies indicate that the western mosquitofish may display ontogenetic changes in cone opsin expression profiles because it exhibits an ontogenetic dietary shift, colors are critical to it in the mating choice of both sexes, and sex steroid estrogen influences its cone opsin expression profiles [ 32 – 36 ].…”