(also called the Bol’shoi Ik), a river in the Bashkir and Tatar ASSR’s; left tributary of the Kama. Length, 571 km; basin area, 18,000 sq km. It flows primarily within the Bugul’ma-Belebei Elevation and is fed mainly by snow. The average water discharge at the village of Nagaibakovo is 45.5 m³/sec. The Ik freezes in late November and thaws in mid-April. The main tributaries are the Dymka, Mellia, and Menzelia on the left and the Usen’ on the right. The river is navigable for 100 km from the mouth. The city of Oktiabr’skii is located on the river. There is petroleum extraction in the river basin. [10–349 -1]