Korean Crevice Salamander

This is a relatively small (42 mm snout-vent length on average) salamander that superficially resembles members of the North American genus Plethodon. It is moderately robust with a well-defined, moderately broad head. The nasolabial groove is relatively inconspicuous but lies in a swollen protuberance on the upper lip. Eyes are relatively small but protuberant. The tongue is attached at front but in an anesthetized specimen it is highly protuberant. The tongue pad it rounded and lack posterior flaps. The relatively rounded snout is prominent, and nostrils are small. There are 14 to 15 costal grooves. The tail is about the same length as the snout-vent length or slightly longer. The tail is round basally but may be slightly laterally compressed towards the posterior. It tapers to a sharp point. Limbs and digits are relatively short. When the limbs are appressed along the trunk, from three to four costal folds are left uncovered. The digits are relatively short and have rounded tips. The fifth toe is noticeably shorter than the fourth. Digits have slight basal webbing. Teeth are small, undifferentiated and weakly bicuspid. There are roughly 45-50 maxillary teeth and 15-20 vomerine teeth. A large, paired patch of paravomerine teeth (total about 150) is present on palate. General coloration is dark, especially along the flanks, but with a dorsal reddish or brownish stripe that extends from the tip of the snout and all along the body and tail. The stripe is most vivid in the pelvic and tail base region. The venter is gray, lighter than the flanks.Discovery of this plethodontid salamander in Korea was a great surprise. It is the only Asian plethodontid known. Although it resembles members of the genus Plethodon in general morphology, its internal anatomy and sequences of nuclear genes (RAG-1) show that it is distinct and not a particularly close relative of Plethodon. In the morphology of its ankle it resembles Aneides, and in its DNA sequence it is shown to be a sister taxon of a clade including Aneides and the desmognathine pletodontids. At present little information is available concerning its general biology or conservation status.This species was discovered 34 years before its description; a specimen has been found in the collection of the Institute for Amphibian Biology, Hiroshima University, Japan, that was collected in 1971 from Mt. Gyeryong by a joint Korean-Japanese team (Nishikawa 2009).Karyotype is 2N=28, with all 14 chromosomes bi-armed and no heteromorphic sex chromosomes. C-banding shows that heterochromatin is concentrated mainly at the centromeres. The genome is large; around 53.5 pg (Sessions et al. 2008).

The species is known from the middle portion of the Korean Peninsula in the country of South Korea. It is known from a number of localities in that region. It occurs on damp, mossy slopes and in rock slides, and is associated with limestone. The relatively young forests (ca. 50 years) of hardwoods and pines in which the species is found are widely distributed and the range may be larger than presently known. Individual salamanders have been found under small rocks and pieces of limestone, and among rocky substrate on a generally fine-grained soil base.

This species is thought to be exclusively terrestrial because it occurs in woodland habitats away from streams and ponds. It appears to be relatively abundant locally but no studies have been undertaken as yet.

The Korean crevice salamander (Karsenia koreana) is a species of lungless salamander. It dwells under rocks in limestone forest areas of the Korean peninsula. It was discovered by Stephen J. Karsen, an American science teacher working in Daejeon, South Korea, in 2003, and described in 2005. Although plethodontid salamanders comprise seventy percent of salamander species worldwide, Karsenia koreana is the first member of this taxon known from Asia. Like other plethodontids, it lacks lungs and breathes through its moist skin. It is the only species in the genus Karsenia.