Freshwater Fishes of the Kuril Islands and Adjacent Regions

Fishes were collected in freshwater habitats during six consecutive summers (1994-1999) on the 30 major islands of the Kuril Archipelago as part of a joint U. S., Russian, and Japanese biotic survey and inventory, which has come to be known as the International Kuril Island Project (IKIP). A total of 39,269 specimens, representing eight families, 12 genera, and 28 species (including two previously undescribed species, 11 new records for the Archipelago, and 33 new records for various islands), was analyzed in the context of published literature on the freshwater fish faunas of the Kuril Islands and adjacent regions, namely Kamchatka, Hokkaido, and Sakhalin. The geologic history of the Archipelago is reviewed in light of present-day fish distributions. As expected, species diversity, as compared to that of Kamchatka and Hokkaido, falls off abruptly as one moves centrally from both the northern and southern ends of the Archipelago, the number of species dropping to zero on some of the central islands. It appears that differences in island size, and therefore available habitat, are the primary determinant of diversity, coupled with the secondary effects of former connections between landmasses and distance from adjacent source biotas.