South Korea is home to a wide variety of native mammals and birds. Some of these, such as the endangered baikal teal, live primarily in the local biome, while others, such as whales, only visit the waters near South Korea seasonally.
Whales are some of South Korea's most spectacular visitors. The whale species that can be found within a few miles of the coast are humpback, sperm and gray whales. Inland, South Korea has river- and lake-dwelling fish, some of which live nowhere else on Earth. Among these are the Somjiny bitterling, the Korean stumpy bullhead, several species of loach and the black shiner.
South Korea has four native species of salamander, notably the Korean crevice salamander. This species is unusual in being the only lungless salamander species known to be endemic to Asia. The adults breathe directly through their skin, not with lungs as the Korean clawed salamander does.
The striped field mouse is common to East Asia, but South Korea has its own variant, the Jeju striped field mouse, which some naturalists have suggested should be classified as its own species. South Korea also has a number of native invertebrates including a katydid (Sphagniana monticola), a moth (Pyrausta nigrimaculata) and a longhorned beetle (Demonax seoulensis).