Most species of the hydraenid beetle genus Ochthebius are associated with fresh water habitats e.g. creek margins. One clade, the vandykei group, succeeded in a very different habitat, fissures and crevices of the supralittoral coastal rocks on both sides of the northern Pacific. One species of this group is known from the North American coasts while seven species were described from the Asian coasts (Jäch & Delgado 2014: https://www.zobodat.at/pdf/KOR_84_2014_0081-0100.pdf). Interestingly, there have been no records of this group from Sakhalin and adjacent islands (e.g., Moneron), although one species, O. yoshitomii (https://www.zin.ru/animalia/coleoptera/images/kv_mak/Neochtebius_granulosus_B_km.jpg; misidentified on the photo as O. granulosus) is common on the coasts of Hokkaido and the Kuril Islands. In summer of 2021 an expedition of the Natural History Museum explored the coastal insect fauna of Sakhalin and samples of the vandykei group were collected at multiple localities. They will be analyzed by the FEZ group Master student Liepa Adomaityte.