The Mating System of Symbiotic Crustaceans

Abstract

This chapter proposes a conceptual model predicting the mating system of symbiotic crustaceans. It assumes that males and females have different optimal mating strategies which they attempt to attain by defending and moving between hosts, and that host characteristics and predation risk limit the behavioral options of symbiotic individuals. Five mating systems are predicted: (i) monogamy when predation risk is high, hosts are scarce, morphologically simple, and small in size; (ii) host-defense polygyny when predation risk is high, hosts are scarce, simple, and intermediate in size; (iii) pure-search polygynandry of mobile females when predation risk is low, hosts are abundant, complex, and large; (iv) pure-search polygynandry of sedentary females when predation risk is moderate to high, hosts are scarce, and extremely small; and (v) female-centered polygyny when predation risk is moderate, hosts are neither abundant nor scarce, and intermediate in size. Empirical evidence supports the model's predictions.