Middendorffinaia mongolica, formerly Middendorffinaia shadini, is a species of unionid mussel endemic to South Primorye, Russia.

Its specific name honours Russian zoologist Vladimir Zhadin.

[5] Middendorffinaia shadini inhabits the river Razdolnaya, its tributaries Rakovka, Olenevka, Komarovka and Kiparisovka, as well as rivers Artemovka, Barabashevka and some parts of the rivers Tesnaya and Gladkaya.

[6] Middendorffinaia shadini is listed in the Red Book of Russia and, particularly, in the Red Book of Primorsky Krai.

[6] Middendorffinaia shadini is sensitive to water pollution and soil contamination.