Is there a competitive relationship between the two ocypodoid crabs, Uca lactea and Ilyoplax pusilla in the habitat use and individual interactions?

Abstract

Two tidal-flat-dwelling ocypodoid crabs, Uca lactea and Ilyoplax pusilla show the similar habitat preferences with respect to intertidal height and substratum. Between populations of U. lactea co-occurring with I. pusilla and those without I. pusilla, their habitat conditions of intertidal height and substratum were compared. The habitat conditions were not significantly different between populations with I. pusilla and those without I. pusilla, suggesting the non-influence of I. pusilla on habitat use by U. lactea. Individual male U. lactea were found to be more aggressive against the neighboring conspecifics than against the neighboring I. pusilla. Less aggressiveness of U. lactea towards I. pusilla is attributable to the habitat use by U. lactea independent of the presence of I. pusilla.