Behavioural and life-history regulation in a unisexual/bisexual mating system: does male mate choice affect female reproductive life histories?
Article first published online: 17 APR 2012
© 2012 The Linnean Society of London
Biological Journal of the Linnean Society
Volume 106, Issue 3, pages 598–606, July 2012
How to Cite
RIESCH, R., PLATH, M., MAKOWICZ, A. M. and SCHLUPP, I. (2012), Behavioural and life-history regulation in a unisexual/bisexual mating system: does male mate choice affect female reproductive life histories?. Biological Journal of the Linnean Society, 106: 598–606. doi: 10.1111/j.1095-8312.2012.01886.x
- Issue published online: 13 JUN 2012
- Article first published online: 17 APR 2012
- Received 21 December 2011; revised 27 January 2012; accepted for publication 27 January 2012
- frequency-dependent mate choice;
- mating preference;
- Poecilia formosa;
- sperm limitation
In theory, unisexual taxa have an advantage over ecologically similar bisexual species because unisexuals produce twice as many daughters and, thus, should quickly outcompete coexisting bisexuals in any given population. For sperm-dependent unisexual (gynogenetic) species, stable coexistence with their bisexual sperm donors can be postulated if male mate choice puts unisexual females at a disadvantage through sperm limitation, thus halving their reproductive output compared to bisexuals (‘behavioural regulation hypothesis’). We tested for a potential life-history signature of male mate choice in a system of coexisting bisexual sailfin mollies (Poecilia latipinna) and gynogenetic Amazon mollies (Poecilia formosa). Specifically, we gave P. latipinna males an opportunity to freely interact (and mate) with both types of females and, after 25 days, quantified the proportion of (1) females with sperm in their genital tract and (2) pregnant females. A higher proportion of P. latipinna females (53.7%) had sperm in their genital tract (compared to only 25.9% in P. formosa), corroborating a previous study on wild-caught fish. This translated into a higher frequency (42.6%) of P. latipinna females being pregnant (compared to 29.6% in P. formosa); however, among pregnant females, no significant differences between species in reproductive life-history traits (such as offspring number or size) were uncovered. Hence, although the findings of the present study confirm that male discrimination against unisexual females leads to reduced reproductive output in unisexuals, the observed magnitude of differences in targeted life histories between the two types of females is unlikely to be the sole factor regulating stable coexistence in this system. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 598–606.