In an attempt to enhance understanding of the niche relations in a space-limited environment, the patterns of microhabitat use were investigated in three coexisting epiphytes on an intertidal gastropod, Lunella coronata coreensis. Our field observations revealed clear spatial and temporal partitioning of shell microhabitats among epiphytes, with the species-specific epiphyte, Pseudocladophora conchopheria, occupying wider micro-niches of hosts in varied sizes than other two epiphytes. Microhabitat utilization patterns were also variable between the two non-species-specific epiphytes. 3-dimensional host shell morphology with temporal variability may create heterogeneous microhabitats on shell surfaces that could allow spatial and temporal niche segregation of epiphytes even on small spatial scale. These results may help us consider the advantages of being species-specific in organisms utilizing limited resources.