4633 Acipenser dauricus Georgi, 1775 Acipenseridae Sturgeons Acipenseriformes Chondrostei Kaluga Asia: Amur basin, ascending far up to the Argun, Shilka, and Onon. In the Amur Liman to the Amur estuary in the Sea of Okhotsk. Adults inhabit some lakes, like Orel Lake above Nikolaevsk. Also in the Ussuri and Sungari, China. Four populations are recognized in the Amur River basin: one lives in the estuary and coastal brackish waters of the Sea of Okhotsk and Sea of Japan, second is found in the lower Amur, third in the middle Amur, and fourth in the lower reaches of the Zeya and Bureya rivers in the Russian river banks (Ref. 40142). Two ecological morphs are present in the estuary population, the 'freshwater' and the 'brackish' water forms (Ref. 40142).