Ecological Studies on the Social Evolution in Ocypodid Crabs

在Uca dussuieri spinata中，雌性广泛分布，雄性通过试图超越竞争对手而接受雌性来竞争。这种物种的求偶和交配发生在地表或雌性防御的洞穴中。相比之下，四头龙的雄性不会进入雌性繁殖的洞穴(资源防御交配系统)，并对其进行防御。地下交配经常发生在雄性守卫的洞穴中，涉及离开洞穴并在蜂群中漫步的雌性。在这些洞穴中，交配也发生在雌性守卫并在其周围觅食的洞穴附近的表面。杜氏棘豆的表面交配已经被改造成一种有利于资源保护的一夫多妻制的模式。在越南，人们发现Ilyopax CrabsI.indqpoensis建造的早期结构通常会在邻近的洞穴附近建造一个土质结构，即路障，并进行洞穴填充，就像在韩国观察到的I。但是，洞穴填塞对维持它们的领土的效果不如在I.ningqposis建造路障。但东道主本身并没有遭受任何切实的不良影响。在这两种情况下，一些岩蟹都有自己的洞穴，而另一种则没有。在M.banzai和I.pingi中，I.pingi用M.banzai的洞穴接触它们的洞穴。同住在寄主物种洞穴中的螃蟹对同一洞穴中的居民没有表现出任何攻击行为。

Mating Systems of UcaIn Uca dussumieri spinata, females are widely dispersed, and males compete by trying to outrace rivals to receptive females. Courtship and mating in this species occur on the surface or in burrows females defend. In contrast, males of U.tetragonon court from and defend burrows to which females come for breeding (resource-defense mating systems). Underground copulations occurred frequently in the burrows males defended, and involved famales who had left their burrows and wandered through the colony. In these, matings also occurred on the surface near burrows that females defended and around which they fed. Surface copulations which occur in U.dussumieri spinata have been modified to a pattern in favor of the resource-defense polygyny in U.tetragonon.Earthen Structures Built by Ilyoplax CrabsI.ninqpoensis in Vietnam was found to commonly build an earthern structure, barricade, near its neighbor's burrow, and to perform burrow filling, as I.dentimerosa observed in Korea. But burrow filling was less effective to maintain their territories than barricade building in I.ninqpoensis.CommensalismMacrophthalmus banzai provide a home for Ilyoplax pingi in Korea and Uca dussumieri spinata for I.orientalis and others in Malaysia. But the host itself suffers no tangible ill-effects. In both cases, some Ilyoplax crabs had own burrows, and the other had not. In M.banzai and I.pingi, I.pingi contact their burrows with a burrow of M.banzai. Crabs that cohabit in burrows of the host species did not show any aggression toward inhabitants in the same burrow.