Female assessment of male functional fertility during mate choice in a promiscuous fish

Abstract

Sexual selection should favour females that can assess the functional fertility of available sexual partners and avoid mating with recently mated, sperm‐depleted males. Our current understanding of the sensory mechanism(s) underlying female assessment of males based on their functional fertility and avoidance of sperm‐depleted males is incomplete. Female Trinidadian guppies (Poecilia reticulata) are known to avoid mating with males that they had previously observed mating with other females. Here, we investigated experimentally the proximate sensory cues that they use to distinguish between paired size‐ and colour‐matched mated and unmated males in the absence of visual public information on their prior mating histories. When only water‐borne chemical cues from the males were available, females avoided the previously mated male and preferred the unmated one, but they chose randomly when only male visual cues (and no chemical cues) were available. They also preferred unmated over mated males when freely swimming with them in a more sensorially complex environment with multiple male cues (i.e., visual, chemical and mechanical cues) concurrently available. Females exhibited no preference for either stimulus males when both were unmated, irrespectively of the sensory environment. These novel results suggest that, in the absence of prior visual public information on the recent mating histories of males, female guppies use olfactory cues putatively emitted by mated males to avoid mating with them. The source and nature of the implicated olfactory cues and the fitness benefits gained by female guppies in sexually preferring males that have not recently mated remain unknown and warrant further research.

Multiple phenotypic traits predict male mating success in a critically endangered frog

“…These categories were calculated using the 25th, 50th, and 75th percentiles. Call rate values outside of this range are likely to present more extreme relationships than the ones presented here ◂ corroboree females to assess and choose males based on fertility (Scarponi and Godin 2018).…”

“…Critically, intrinsic genetic quality may also be associated with superior sperm performance (Locatello et al 2006), with evidence in various taxa that males of higher genetic quality have increased sperm viability, motility, and longevity (Locatello et al 2006;Evans et al 2007); these are sperm traits known to influence fertilization success. Obtaining direct fertility benefits from mate choice is likely to be particularly important to females in polygynous mating systems, where males mate consecutively with multiple females, and highly successful males risk becoming sperm depleted (Scarponi and Godin 2018). In the P. corroboree mating system males are polygynous (Kelleher et al 2021a), and in the present study the most successful males would have mated with at least three females (estimated based on female average clutch size and the total number of eggs they received throughout the entire season).…”

Phenotype-dependent social environment choice in the male Trinidadian guppy

“…For example, it has previously been shown that female guppies will avoid mating with males who have recently mated with another female (Scarponi et al 2015), a phenomenon which is seen in other species including cockroaches (Harris and Moore 2005), Drosophila (Loyau et al 2012), and in some circumstances, crayfish (Mellan et al 2014). Although female guppies can use chemical cues to assess a male's recent mating history (Scarponi & Godin 2018), such cues were not available to females in this experiment as they only had visual cues to assess the males. It therefore seems unlikely that male prior mating history would have affected female preferences observed in the current experiment.…”