Jormalainen V, Tuomi J, Yamamura N
Satakunta Environmental Research Centre, University of Turku, FIN-28900 Pori, Finland.
Department of Ecology, Theoretical Ecology, Ecology Building, Lund University, S-223 62 Lund, Sweden.
Behav Processes. 1994 Nov;32(3):265-83. doi: 10.1016/0376-6357(94)90047-7.
Precopulatory guarding in Crustacea is usually analyzed as a male decision problem. We suggest an alternative possibility that precopula is established as a result of intersexual conflict over precopula duration. Such a conflict can be expected when the male optimum for precopula duration exceeds the female optimum. As a result, males should start precopulatory attempts earlier, while females should resist until close to receptivity. Our analysis reveals two potential sources of conflict: (1) sexual differences in survival probabilities before and during the mate-guarding; and (2) sexual differences in the probability of finding a mate. The latter is perhaps a more probable source of intersexual conflict, since male biased operational sex ratios are common in mate-guarding Crustacea. The former requires that female moulting cycle is synchronous, whereas the latter may operate in populations with asynchronous moulting cycles as well. We further studied the expected intensity of behavioural conflicts in terms of expected present and future fitness gains. In the beginning of the female moulting cycle, there is no conflict. Conflict arises as males start the guarding attempts and females are motivated to resist, and ceases with a decrease in the female's motivation to resist. Several assumptions and predictions of the model are discussed and compared with the behavioural patterns observed in the aquatic isopod Idotea baltica.
甲壳纲动物交配前的守护行为通常被作为雄性的决策问题来分析。我们提出另一种可能性，即交配前状态是两性在交配前持续时间上的冲突所导致的结果。当雄性对于交配前持续时间的最优值超过雌性的最优值时，就可以预期会出现这样的冲突。结果是，雄性应该更早地开始交配前的尝试，而雌性则应抵抗，直到接近接受交配的状态。我们的分析揭示了冲突的两个潜在来源：（1）在守护配偶期间及之前生存概率的性别差异；（2）找到配偶概率的性别差异。后者可能是两性冲突更有可能的来源，因为在守护配偶的甲壳纲动物中，雄性偏向的操作性别比很常见。前者要求雌性的蜕皮周期同步，而后者在蜕皮周期不同步的种群中也可能起作用。我们根据预期的当前和未来适合度收益，进一步研究了行为冲突的预期强度。在雌性蜕皮周期开始时，没有冲突。当雄性开始守护尝试且雌性有动机抵抗时冲突出现，并随着雌性抵抗动机的降低而停止。讨论了该模型的几个假设和预测，并与在水生等足类动物波罗的海麦秆虫中观察到的行为模式进行了比较。
