Lake of Neuchatel is the bigest lake entirely in Switzerland. Geneva lake is shared with France and Konstance lake is shared with Germany. The lake receives the Orbe River, the Arnon, the Areuse, and the Mentue. The canal of Thielle drains the lake into Lake Biel-Bienne and is part of regulation system for the lakes and the rivers of the Seeland region. Lake Neuchâtel was the home of the now extinct species of deepwater trout Salvelinus neocomensis.