Saimaa ringed seal

The Saimaa ringed seal (Pusa saimensis, Finnish: saimaannorppa) is a species of seal. It is among the most endangered seals in the world, having a total population of only about 500 individuals. The only existing population of these seals is found in Lake Saimaa, Finland. It has lived in complete isolation from other ringed seal populations for around 9,500 years, and have diverged into a morphologically and ecologically different species or subspecies. The population is descended from ringed seals that were separated from the rest when the land rose after the last ice age. This seal, along with the Baikal seal, the Ladoga seal, and the Ungava seal, is one of the few living freshwater seals. The Saimaa ringed seal was previously considered a subspecies of ringed seal called Pusa hispida saimensis, but in 2025 was classified as its own species after genetic research revealed its closest living relatives being ringed seals from arctic North America, rather than Baltic and Ladogan ringed seals as was previously thought, and having diverged as far back as 60 000 years ago to form its own evolutionary branch.