Public Information Influences Sperm Transfer to Females in Sailfin Molly Males

Abstract

In animals, including humans, the social environment can serve as a public information network in which individuals can gather public information about the quality of potential mates by observing conspecifics during sexual interactions. The observing individual itself is also a part of this information network. When recognized by the observed conspecifics as an audience, his/her presence could influence the sexual interaction between those individuals, because the observer might be considered as a potential mate or competitor. One of the most challenging questions in sexual selection to date is how the use of public information in the context of mate choice is linked to the fitness of individuals. Here, we could show that public information influences mate-choice behaviour in sailfin molly males, Poecilia latipinna, and influences the amount of sperm males transfer to a female partner. In the presence of an audience male, males spent less time with the previously preferred, larger of two females and significantly more time with the previously non-preferred, smaller female. When males could physically interact with a female and were faced with an audience male, three audience females or no audience, males transferred significantly more sperm to a female partner in the presence of an audience male than with female audience or no audience and spent less time courting his female partner. This is the first study showing that public information use turns into fitness investment, which is the crucial factor to understand the role of public information in the dynamic processes in sexual selection.

Sexual selection, social information and male mate choice in a promiscuous fish

“…My current results on male guppy courtship behaviour differ from those of a recent study by Nöbel and Witte (2013), who compared the courtship behaviour of male sailfin mollies in the presence or absence of a conspecific audience. They found that male mollies spent less time following a stimulus female, but did not alter the frequency of their courtship displays, when a male audience was present compared to when either no audience was present or when the audience was comprised of three sexually mature females.…”

“…the demonstrator) can provide benefits to the copier (e.g. reduced sampling costs), there can also be associated costs with copying for both the demonstrator and copier, such as increased resource competition and risk of sperm competition (Nöbel and Witte 2013;Dubois 2015;Castellano et al 2016). When demonstrators and eavesdroppers compete for the same limited resources (e.g.…”

“…An increasing body of work, mainly on polygamous fishes, has demonstrated that the mere presence of an audience of one or more sexual competitors can influence a male's mating preference and mating tactics (e.g. Dzieweczynski et al 2005;Plath et al 2008aZiege et al 2008Ziege et al , 2009Dzieweczynski and Walsh 2010;Mautz and Jennions 2011;; Chapters 6 and 8) and sperm allocation strategy (Nöbel and Witte 2013).…”

“…To date, there has been limited empirical research on the potential effect of an audience on the use of alternative mating tactics in males (see Nöbel and Witte 2013).…”

Does Individual Variation in Male Mate Choice Copying Reflect Differences in Social Responsiveness?

“…We investigated so-called 'audience effects' [43,44] during which males alter their mate choice behavior strategically in response to rival presence [45][46][47]. Poeciliid males, when faced with a rival male during their mate choice (which may observe and later copy their mating decisions) lower their sexual effort and conceal their mate preference, or they even trick their observers by interacting with the previously non-preferred female [32,[48][49][50][51][52][53][54].…”