Theromyzon tessulatum

Geographic distribution. Palaearctic and Nearctic regions. Irtysh River area: the Bukhtarma water reservoir (N 49 º 36 ′ 58 ′′ / E 83 º 31 ′ 33 ′′; N 49 º 37 ′ 01 ′′ / E 83 º 34 ′ 18 ′′). Ecology. This is a widespread but rare species. It can be found in swamped coastal areas. It prefers stagnant water. Feeds on the blood of vertebrates. Most likely hosts are fishes, water birds or amphibians. FAMILY: PISCICOLIDAE Johnston, 1865 (synonym Ichthyiobdellidae Leuckart, 1863) Species: Piscicola geometra (Linnaeus, 1758) Geographic distribution. Holarctic region. Irtysh River area: the Shulbinsk water reservoir (N 50 º 22 ′ 53 ′′ / E 81 º 06 ′ 13 ′′), the Bukhtarma water reservoir (N 49 º 36 ′ 58 ′′ / E 83 º 31 ′ 33 ′′; N 49 º 37 ′ 01 ′′ / E 83 º 34 ′ 18 ′′; N 49 º 37 ′ 39 ′′ / E 83 º 27 ′ 21 ′′). Ecology. A widespread fish parasite. It was detected both in fish and in the free-living state (on various substrates). This species does not occur in mountain streams. FAMILY: ERPOBDELLIDAE Blanchard, 1894 Species: Erpobdella octoculata (Linnaeus, 1758) Geographic distribution. Widespread Palaearctic species. Irtysh River area: the Irtysh River (N 50 º 25 ′ 26 ′′ / E 80 º 12 ′ 34 ′ '; N 52 º 16 ′ 52 ′′ / E 76 º 56 ′ 06 ′′; N 52 º 18 ′ 33 ′′ / E 76 º 53 ′ 00 ′′; N 52 º 19 ′ 17 ′′ / E 76 º 53 ′ 22 ′′), the Semipalatinka channel (N 50 º 24 ′ 06 ′′ / E 80 º 14 ′ 36 ′′), the Shulbinsk water reservoir (N 50 º 22 ′ 53 ′′ / E 81 º 06 ′ 13 ′′; N 50 º 23 ′ 35 ′′ / E 81 º 05 ′ 36 ′′; N 50 º 223 ′ 53 ′′ / E 81 º 06 ′ 13 ′′), the Bukhtarma water reservoir (N 49 º 36 ′ 58 ′′ / E 83 º 31 ′ 33 ′′), and Lake Bolshoe (N 50 º 43 ′ 16 ′′ / E 79 º 40 ′ 49 ′′). Ecology. This is the most abundant species of the plain river areas.