Most mud snail species of the family Potamididae face extinction in Japan, as c. 40% of their habitats (= tidal flats) have been lost during the last century. While Cerithidea rhizophorarum is designated as a ‘near-threatened’ species by central and local governments, it was found in as many as 69 of 157 tidal flats (Ministry of the Environment 2007), presumably due to its wide habitat (sediment) preference. The present study investigated the distribution and recruitment of C. rhizophorarum in relation to two contrasting habitat structures, mud and coarse sand, in a major tidal flat of central Japan. I report on new information generated by sediment manipulation experiments and consideration will be given to the species’ variable strategy in efficiently utilizing different habitat characteristics.