Schistura oedipus

(Kottelat, 1988) Kottelat 1990

Schistura oedipus
Schistura oedipus pink morph. Photograph by Paul Loiselle.
CypriniformesCobitoidei Nemacheilidae


Nemacheilus oedipus  Kottelat 1988




Holotype: AMS I.25986‑002 70.4mm SL

Paratype: AMS I.25986‑001 74.3mm SL


Type locality: Tham Nam Lang, Pang Ma Pha District, Mae Hong Son Province, Thailand (19o31'N, 98o09'E).

Known also from Tham Mae La Na, where it coexists with Cryptotora thamicola, Tham Plah (= Tham Hud), Tham Ban Pok Kut, Ban Nong Pha Cham and “Christmas Cave” (Richard Borowsky pers. comm.).


Within Tham Mae La Na this species lives in gour pools while its co-inhabitant, Cryptotora thamicola, is found in water cascading over flowstone. A population estimate suggests that there are 104-105 individuals, a large population for a subterranean fish (Trajano, Mugue, Krejca, Vidthayanon, Smart and Borowsky 2002).  


Nemacheilus reidi is postulated as a sister species of this species although it is pointed out that the relationships of the fish fauna of Thailand are very poorly known (Kottelat 1988). Data on pigmentation and behaviour collected by Trajano, Mugue, Krejca, Vidthayanon, Smart and Borowsky (2002) suggest that this species is a neo stygobite.

Conservation Status

[VU D2:3.1:2011]

(Vidthayanon, C. 2011. Schistura oedipus. The IUCN Red List of Threatened Species 2011: Downloaded on 14 July 2017). This species is only known from subterranean streams in caves of Pang Mapha karst formation in north-western Thailand. Given the nature of the hydrological system and the likely limited extent of occurrence (considered to be much less than 2,000 km²), the species is assessed as Vulnerable (D2). Current and potential threats are tourism development and degradation of the surrounding watershed and water quality. R (IUCN 1990), R (IUCN 1993).

Museum Holdings

As above only.

Key References

Kottelat, M. Journal Article 1988 Two species of cavefishes from northern Thailand in the genera Nemachilus and Homaloptera (Osteichthyes, Homalopteridae)
Kottelat, M. Journal Article 1990 New species and populations of cave nemacheilines in south and south-east Asia (Osteichthyes, Balitoridae)
Deharveng, L. and Bedos, A. Book Section 2001 Thailande
Borowsky, R. and Mertz, L. Journal Article 2001 Genetic differentiation among populations of cave fish Schistura oedipus (Cypriniformes: Balitoridae)
Borowsky, R.L. and Vidthayanon, C. Journal Article 2001 Nucleotide diversity in populations of balitorid cave fishes from Thailand
Trajano, E., Mugue, N., Krejca, J., Vidthayanon, C., Smart, D. and Borowsky, R. Journal Article 2002 Habitat, distribution, ecology and behaviour of cave balitorids from Thailand (Teleostei: Cypriniformes)
Kottelat, M. Journal Article 2012 Draconectes narinosus, a new genus and species of cave fish from an island of Halong Bay, Vietnam (Teleostei: Nemacheilidae).
Duboue, E.R. and Borowsky, R. Journal Article 2012 Altered rest-activity patterns evolve via circadian independent mechanisms in cave adapted balitorid loaches
Brancelj, A., Boonyanusith, C., Watiroyram, S. and Sanoamuang, L. Journal Article 2013 The groundwater-dwelling fauna of Southeast Asia
Ellis, M. Journal Article 2018 The recorded fauna of the limestone caves of Thailand to April 2018
Ellis, M. Journal Article 2020 The caves of northern Thailand
Marak, W.K. and Singh, Y.L. Journal Article 2023 Osteology of incomplete lateral lined schisturid loaches of Meghalaya: a comparative account
Schistura oedipus gold morph. Photograph by Paul Loiselle.
Schistura oedipus regenerating melanin. Photograph by Paul Loiselle.