The Korean crevice salamander (''Karsenia koreana'') is a species of

lungless salamander Plethodontidae, or lungless salamanders, are a family of salamanders. Most species are native to the Western Hemisphere, from British Columbia to Brazil, although a few species are found in Sardinia, Europe south of the Alps, and South Korea. In ...

. It dwells under rocks in

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

forest areas of the

Korean peninsula Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

. It was discovered by Stephen J. Karsen, an American science teacher working in

Daejeon Daejeon () is South Korea's fifth-largest metropolis, with a population of 1.5 million as of 2019. Located in the central-west region of South Korea alongside forested hills and the Geum River, the city is known both for its technology and ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

, in 2003, and described in

2005 File:2005 Events Collage V2.png, From top left, clockwise: Hurricane Katrina in the Gulf of Mexico; the Funeral of Pope John Paul II is held in Vatican City; "Me at the zoo", the first video ever to be uploaded to YouTube; Eris was discovered in ...

. Although

plethodontid Plethodontidae, or lungless salamanders, are a family of salamanders. Most species are native to the Western Hemisphere, from British Columbia to Brazil, although a few species are found in Sardinia, Europe south of the Alps, and South Korea. In ...

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''.

Systematics and biogeography

Cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

analysis using

Bayesian analysis Bayesian inference is a method of statistical inference in which Bayes' theorem is used to update the probability for a hypothesis as more evidence or information becomes available. Bayesian inference is an important technique in statistics, and ...

of molecular data places ''Karsenia koreana'' as

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

containing ''

Aneides Climbing salamanders is the common name for plethodontid (lungless) salamanders of the genus ''Aneides''. It contains 10 species native to North America, distributed between the Pacific Coast (7 species), Sacramento Mountains (1 species), and App ...

'' and the desmognathine salamanders. This implies that plethodontid salamanders may have had a worldwide range 60 to 100 million years ago. As the global climate cooled, New World taxa thrived while Old World populations declined. Other plants and animals currently found in Asia and North America share close relationships, showing a similar pattern of

biogeography Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

Description

Males measure and females in snout–vent length. The habitus is moderately robust. The head is relatively broad. The eyes are small and moderately protuberant. There are 14–15

costal groove The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi-r ...

s. The tail is round basally but becomes in some individuals laterally compressed towards its tip. Complete tail (i.e., non-regenerated) is about as long as the snout–vent length. The species is darkly pigmented. There is a broad dorsal stripe of variable color (reddish to yellowish brown, tan, or dark brown) and distinctness (prominent and bright to obscure). The lateral surfaces are uniformly dark but have an obscure overlay of small, whitish speckles. The ventral surfaces are pale with moderately large, whitish flecks that are absent along the midline.

Habitat and conservation

The species occurs in damp talus slopes and rockslides of limestone in young forests dominated by ''

Pinus densiflora ''Pinus densiflora'', also called the Japanese red pine, the Japanese pine, or Korean red pine, is a species of pine tree native to East Asia. Distribution and habitat ''P. densiflora'' has a home range that includes Japan, the Korean Peninsula, ...

'' and ''

Quercus mongolica ''Quercus mongolica'', commonly known as Mongolian oak, is a species of oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The commo ...

'', mostly under small stones. Although the species is considered locally common, and reasonably widespread (as of 2006, it was known from more than 20 sites), it has not been well studied in the field. Thus, its natural history, population dynamics, and reproductive behavior remain unknown.

References

{{Taxonbar, from=Q1325600 Plethodontidae Endemic fauna of Korea Amphibians of Korea Amphibians described in 2005 Taxa named by David B. Wake