Uca pugilator

About: Uca pugilator is a research topic. Over the lifetime, 376 publications have been published within this topic receiving 12303 citations.

Independent and interactive effects of two facilitators on their habitat-providing host plant, Spartina alterniflora

Abstract: The role of habitat-providing species in facilitating associated species abundance and diversity is recognized as a key structuring force in many ecosystems. Reciprocal facilitation by associates, often involving multiple species, can be important for the maintenance of the host species. As with other multi-species interactions (e.g. multiple predator effects), non-additive relationships may be common among these associates, yet relatively few studies have examined potential interactions among multiple facilitator species. We combined field surveys and a mesocosm experiment to examine the independent and interactive effects of two co-occurring facilitator species, ribbed mussels Geukensia demissa and fiddler crabs Uca pugilator, on their host salt marsh plant species, cordgrass Spartina alterniflora. We also experimentally examined how these relationships varied across different host plant genotypes. Overall, facilitator effects increased with increasing facilitator density. There was a significant interaction between mussel and fiddler crab presence, indicating that the effects of each species on cordgrass were dependent on the presence of the other facilitator species. In addition, there were strong interactions among mussels, fiddler crabs, and plant genotype, with greater variation in the performance of individual genotypes when fiddler crabs were absent. Our work reinforces the importance of considering multiple responses when assessing the functional redundancy of co-occurring facilitators, as species are seldom completely redundant across the range of services they provide. It also highlights that the strength and direction of species interactions can vary due to genetic variation within the interacting species.

Effects of time of year and limb removal on rates of ecdysis of eyed and eyestalkless fiddler crabs, Uca pugilator

Abstract: The incidence of ecdysis among monthly samples of female Uca pugilator, both intact and eyestalkless, was determined from May, 1974 through April, 1975. Among both the intact and eyestalkless crabs the percentages of the crabs that underwent ecdysis varied during the year. During the height of the breeding season in particular, ecdyses were rare among the eyestalkless crabs and absent among the intact ones. The effects of limb removal, either followed by or preceded by eyestalk removal, on the rate of ecdysis were also determined. Eyestalkless crabs from which 4 walking legs were removed either the day before or the day after their eyestalks had been removed underwent ecdysis at a slower rate than crabs lacking only eyestalks, but faster than crabs lacking only 4 walking legs. The high incidence of precocious ecdyses induced by removing large numbers of limbs from eyed crabs appears to be due to the number of limbs removed and not to the weight or volume of limb tissue removed.