2012 Volume 6 Pages 71-80
The author conducted a survey of the distribution of Lefua echigonia and Cottus spp. in three river systems in the vicinity of Lake Izunuma: the Eai, Kyu-Hasama and Hasama. In addition to the three aforementioned river systems, Lefua echigonia was also surveyed in the Naruse, Kinryu and Ichinono rivers. Based on this survey, it was confirmed that Lefua echigonia is distributed with its northern-most range limit in some tributaries of the Hasama. As for Cottus nozawae, it was confirmed to populate three tributaries of the Hasama. It is unknown whether Cottus pollux (large-egg type) still occurs in the upper Hasama after the Iwate-Miyagi Nairiku Earthquake in 2008, but Cottus nozawae is found in its original habitats even after the earthquake. The author reports that the Nagasaki river, a tributary of the Hasama, is an unusual river in Miyagi Prefecture in the sense that it is a shared environment for both Lefua echigonia and Cottus nozawae.
