page_title: Alternative mating strategy
section_title: Marine isopod (Paracerceis sculpta)
hierarchical_section_title: Alternative mating strategy / Alternative mating strategies / Female mimicry by males / Marine isopod (Paracerceis sculpta)
caption_attribution_description: English: An illustration showing the relative sizes and shapes of the different forms of Paracerceis sculpta
context_page_description: An alternative mating strategy is a strategy used by male or female animals, often with distinct phenotypes, that differs from the prevailing mating strategy of their sex. Such strategies are diverse and variable both across and within species. Animal sexual behaviour and mate choice directly affect social structure and relationships in many different mating systems, whether monogamous, polygamous, polyandrous, or polygynous. Though males and females in a given population typically employ a predominant reproductive strategy based on the overarching mating system, individuals of the same sex often use different mating strategies. Among some reptiles, frogs and fish, large males defend females, while small males may use sneaking tactics to mate without being noticed.
context_section_description: In the isopod Paracerceis sculpta there are three genetically distinct male morphs. Alpha males, which represent the largest and most common male morph, tend to defend harems in order to monopolize access to a large number of females.  This is the predominant mating strategy in this species.  Beta males are about the same size as female isopods, and they take advantage of that fact by mimicking female behaviour in order to enter harems and gain access to fertile females.  Gamma males are the smallest morph. These individuals adopt a sneaking strategy and rely on their small body size to enter harems undetected and remain in them while they seek mating opportunities. These distinct strategies, all determined by a single genetic locus, give equivalent lifetime mating success to each of the three morphs, indicating that natural selection is not acting on one morph more strongly than another.  All three alleles expressed in the population will continue to contribute to male morphology as long as the reproductive success granted by each one continues to be as beneficial as the others.
caption: Paracerceis sculpta
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