Intersexual conflict over precopula duration in mate guarding crustacea

Area of Science:

• Behavioral Ecology
• Evolutionary Biology
• Crustacean Biology

Background:

• Precopulatory guarding in Crustacea is typically viewed as a male-driven decision.
• This perspective overlooks potential conflicts arising from differing optimal precopula durations between sexes.

Purpose of the Study:

• To propose and analyze intersexual conflict over precopula duration as an alternative explanation for precopulatory guarding in Crustacea.
• To investigate the sources and dynamics of this conflict, considering factors like survival and mate-finding probabilities.

Main Methods:

• Developed a theoretical model examining intersexual conflict over precopula duration.
• Analyzed potential conflict sources: sexual differences in survival and mate-finding probabilities.
• Studied the intensity of behavioral conflicts based on fitness gains and compared model predictions with observed behaviors in *Idotea baltica*.

Main Results:

• Intersexual conflict over precopula duration is a viable alternative to male-decision models.
• Conflict intensity varies with the female's receptivity cycle, arising when males initiate guarding and ceasing as female resistance decreases.
• Sexual differences in mate-finding probability, especially with male-biased operational sex ratios, are a probable driver of conflict, applicable even with asynchronous molting.

Conclusions:

• Precopulatory guarding in Crustacea can be understood as a negotiation shaped by intersexual conflict over duration.
• The model highlights the importance of considering differing fitness optima between sexes in behavioral ecology.
• Observed behaviors in *Idotea baltica* align with the predictions of the intersexual conflict model.