Sperm Competition and Sexual Conflict


Sperm competition arises whenever multiple males compete to fertilize a female’s eggs. Sperm competition, however, also affects and is affected by interactions between the sexes. Female behavior influences sperm competition and multiple male paternity can lead to conflict between the sexes over mating, fertilization and parental care. We have studied how sperm competition affects and is affected by interactions between the sexes empirically in the ocellated wrasse (e.g. Alonzo et al. 2016, Alonzo 2000) and theoretically using evolutionary game theory (e.g. Requena and Alonzo 2014, Alonzo and Pizzari 2010).


Want to know more? See the papers below (or a complete list HERE)

Alonzo SH, Stiver KA+, Marsh-Rollo S. 2016. Ovarian fluid allows directional cryptic female choice despite external fertilization. Nature Communications 7:12452 (http://dx.doi.org/10.1038/ncomms12452)

Requena GS+, Alonzo SH. 2014. Female sperm use and storage between fertilization events drive sperm competition and male ejaculate allocation. Evolution 68: 3433–3444 (http://dx.doi.org/10.1111/evo.12540)

Alonzo SH, Pizzari T. 2010. Male fecundity stimulation: conflict and cooperation within and between the sexes. American Naturalist. 175(2): 174-185 (http://dx.doi.org/10.1086/649596)

Alonzo SH, Warner RR. 2000. Allocation to mate guarding or increased sperm production in a Mediterranean wrasse. American Naturalist 156(3): 266-275 (http://dx.doi.org/10.1086/303391)