The Baikal seal, Lake Baikal seal, or Nerpa, is a species of earless seal endemic to Lake Baikal in Siberia. Like the Caspian seal, they are related to the Arctic ringed seal. The Baikal Seal is the smallest of the true seals and is the only exclusively freshwater pinniped species. Baikal seals are the longest-lived of seals and they feed their young on milk twice as long as other seals .