Abstract
In the fiddler crab Uca lactea, the relative frequencies of two mating types, surface mating and underground mating, were compared between high-density and low-density areas. The proportions of the two mating types were not different between the two sites. The proportions of wandering females and waving males were not different between the two sites. Thus, the population density of U. lactea did not influence the frequency of these mating-related behaviors or the relative frequencies of the two mating types.
