Acanthamoeba astronyxis strains, isolated from intertidal belts of Sagar Island (21°30′ to 21°50′ N and 88°04′ to 88°08′ E) facing Bay of Bengal, were cultured in saline distilled water agar medium supplemented with Escherichia coli as food bacterium. Population growth in bay water agar, cerophyl bay water agar and soil extract distilled water agar were compared with special reference to devised saline distilled water agar medium. The overall growth showed little variation over ranges of media salinity (5-30‰). However, greater values were encountered in media of intermediate range. Isolate from mangrove litter-soil of highest high tide belt (strains) grew more efficiently in cerophyl bay water agar and soil extract distilled water agar media while mid-littoral and lowest low tide isolates preferred bay water agar and saline distilled water agar media more. © 1987 Indian Academy of Sciences.