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Reptiles of Thailand

Species of Thailand

Checkered keelback

Thai: งูลายสอใหญ่, ngu lai sor yai

Binomial name: Fowlea piscator, Johann Gottlob Theaenus Schneider, 1799

The checkered keelback or Asiatic water snake (Xenochrophis piscator) is a common species of nonvenomous snake found in Asia.


This snake's eyes are rather small, and shorter than its distance from the nostril in the adult. Its rostral scale is visible from above. The internasal scales are much narrowed anteriorly and subtriangular, with the anterior angle truncated and as long as the prefrontal scales. The frontal scale is longer than its distance from the end of the snout, and as long as the parietals or a little shorter. The loreal is nearly as long as it is deep. There is one preocular and three (rarely four) post-oculars. Its temporals are 2+2 or 2+3. There are normally nine upper labials, with the fourth and fifth entering the eye and five lower labials in contact with the anterior chin-shields, which are shorter than the posterior. Scales are arranged in 19 rows, strongly keeled, with outer rows smooth. Ventrals are at 125–158, anal divided, with subcaudals at 64–90. Coloration is very variable, consisting of dark spots arranged quincuncially and often separated by a whitish network, or of black longitudinal bands on a pale ground, or of dark cross bands, with or without whitish spots. Two oblique black streaks, one below and the other behind the eye, are nearly constant, lower parts white, with or without black margins to the shields.

A rare case of autotomy is reported from Vietnam.


This snake is found in or near freshwater lakes or rivers. It feeds mainly on small fish and water frogs.


The species is found in Afghanistan, Bangladesh, Pakistan, Sri Lanka, India, Myanmar, Nepal, Thailand, Laos, Cambodia, Vietnam, West Malaysia, China (Zhejiang, Jiangxi, Fujian, Guangdong, Hainan, Guangxi, Yunnan), Taiwan, and Indonesia (Sumatra, Java, Borneo, Celebes = Sulawesi)

type locality: "East Indies"

Local names

  • Assamese – ঢোঁৰা সাপ
  • Bengali - ঢোঁড়া সাপ
  • Odia - ଧଣ୍ଡ ସାପ
  • Gujarati – dendu saap
  • Hindi – Dendu saap
  • Indonesia - Bandotan tutul
  • Kannada - ನೀರು ಹಾವು
  • Marathi - दिवड
  • Malayalam - നീർക്കോലി
  • Tamil - கண்டங்கண்டை நீர்க்கோலி (Kandangkandai Neerkoli)
  • Telugu - నీరు కట్టు(neeru kattu)

Other references

  • Dutt, Kalma 1970 Chromosome Variation in Two Populations of Xenochrophis piscator Schn. from North and South India (Serpentes, Colubridae). Cytologia 35: pp. 455–464
  • Schneider, J. G., 1799 Historiae Amphibiorum narturalis et literariae. Fasciculus primus, continens Ranas. Calamitas, Bufones, Salamandras et Hydros. Jena, 266 S.

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Scientific classification

Fowlea piscator

Common names

  • German:
    • Gewöhnliche Fischnatter
    • Fischernatter
  • English:
    • Asiatic water snakes
    • Checkered keelback
  • Thai:
    • งูลายสอใหญ่, ngu lai sor yai
    • งูสา, ngu saa


  • Xenochrophis piscator melanzostus, Johann Ludwig Christian Gravenhorst, 1807

    Range: Indonesia (Borneo Java, Sulawesi?, Sumatra), India (Andaman and Nicobar Islands).

  • Xenochrophis piscator piscator, Johann Gottlob Theaenus Schneider, 1799

    Range: Bangladesh, Bhutan, India, Myanmar, Pakistan, People's Republic of China (including Hainan), Sri Lanka, Taiwan and Thailand.


  • Fowlea piscator, Jayaditya Purkayastha et al. (2019)
  • Natrix piscator, Ramesh Singh et al. (2016)
  • Xenochorpis piscator, Fellows (in error) (2015)
  • Xenochrophis piscator, Van Stanley Bartholomew Wallach et al. (2014)
  • Xenochrophis piscator, T.S.N. Murthy (2010)
  • Xenochrophis piscator, Tanya Chan-Ard et al. (1999)
  • Xenochrophis piscator, Merel J. Cox et al. (1998)
  • Xenochrophis piscator, E. V. Malnate & Sherman Anthony Minton (1965)
  • Natrix piscator, Michael Wilmer Forbes Tweedie (1954)
  • Natrix piscator, Malcolm Arthur Smith (1943)
  • Nerodia (Tropidonotus) piscator, Frank Wall (1921)
  • Tropidonotus piscator, Frank Wall (1908)
  • Natrix piscator, Leonhard Hess Stejneger (1907)
  • Tropidonotus piscator lateralis, Frank Wall (1907)
  • Tropidonotus piscator punctatus, Frank Wall (1907)
  • Tropidonotus piscator, George Albert Boulenger (1893)
  • Tropidonotus quincunciatus, John Anderson (1871)
  • Tropidonotus quincunciatus, William Theobald (1868)
  • Amphiesma flavipunctatum, Edward Hallowell (1861)
  • Tropidonotus quincunciatus, Albert Charles Lewis Günther (1859)
  • Tropidonotus quincunciatus, André Marie Constant Duméril, Gabriel Bibron & Auguste Duméril (1854)
  • Tropidonotus quincunciatus, Hermann Schlegel (1837)
  • Col. quincunciatus, Hermann Schlegel (1837)
  • Coluber funebris, Hermann Schlegel (1837)
  • Coluber sinuatus, Hermann Schlegel (1837)
  • Coluber bengalensis, John Edward Gray (1835)
  • Coluber bengalensis, John Edward Gray (1834)
  • Coluber rectangulus, John Edward Gray (1834)
  • Natrix piscator, Blasius Merrem (1820)
  • Coluber anostomosatus, François Marie Daudin (1803)
  • Coluber umbratus, François Marie Daudin (1803)
  • Coluber braminus, François Marie Daudin (1803)
  • Coluber mortuarius, François Marie Daudin (1803)
  • Coluber dora, François Marie Daudin (1803)
  • Hydrus piscator, Johann Gottlob Theaenus Schneider (1799)
  • Hydrus palustris, Johann Gottlob Theaenus Schneider (1799)

Conservation status

Not Evaluated

Not Evaluated

Xenochrophis piscator (head)

Xenochrophis piscator (head)

Creative Commons Attribution-ShareAlike 4.0 International Thai National Parks

Xenochrophis piscator

Xenochrophis piscator

Creative Commons Attribution-ShareAlike 4.0 International Thai National Parks

Xenochrophis piscator (ready to shed)

Xenochrophis piscator (ready to shed)

Creative Commons Attribution-ShareAlike 4.0 International Thai National Parks

Xenochrophis piscator

Xenochrophis piscator

Creative Commons Attribution-ShareAlike 4.0 International Thai National Parks

Distribution map of Checkered keelback, Fowlea piscator in Thailand

Range map of Fowlea piscator in Thailand

Important note; our range maps are based on limited data we have collected. The data is not necessarily accurate or complete.

Special thanks to Ton Smits, Parinya Pawangkhanant, Ian Dugdale and many others for their contribution for range data.

It is free to use this map on various media. See the creative common license terms by clicking "CC" icon below the map. But remember, again; the map may not be accurate or complete.

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