This study is devoted to microevolutionary processes in populations of marine snails of subgenus Neritrema (Gastropoda, Littorinidae). We analyzed the microhabitat distribution of 5 cryptic species of molluscs (Littorina saxatilis (Olivi, 1792); Littorina arcana Hannaford Ellis, 1978; Littorina compressa Jeffreys, 1865; Littorina obtusata (Linnaeus, 1758); Littorina fabalis (Turton, 1825)) within the intertidal zone and potentially related morphological and physiological characteristics. The data was collected at two geographic locations (Saltstraumen, Norwegian Sea, 66°58'10.2"N 13°58'26.5"E, collection dates 29.06-5.07.2019; Varangerfjord, Barents Sea, 70°04'03.9"N 29°58'40.1"E, collection dates 09.07-12.07.2019). Additional information may be found in the mentioned paper.