Thai National Parks

Species of Thailand

Checkered keelback

Fowlea piscator, Johann Gottlob Theaenus Schneider, 1799

(In Thai: งูลายสอใหญ่, ngu lai sor yai)

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)

Conservation status

Not Evaluated

Not Evaluated


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Fowlea piscator
Fowlea piscator
Xenochrophis piscator (head)
Xenochrophis piscator
Xenochrophis piscator (ready to shed)
Xenochrophis piscator

Range Map

Distribution map of Checkered keelback, Fowlea piscator in Thailand
  • Bang Khen District, Bangkok
  • Doi Inthanon National Park
  • Doi Saket District, Chiang Mai
  • Hang Dong District, Chiang Mai
  • Hua Hin District, Prachuap Khiri Khan
  • Huai Kha Khaeng Wildlife Sanctuary
  • Kaeng Krachan National Park
  • Khao Yai National Park
  • Khun Tan District, Chiang Rai
  • Ko Chang District, Trat
  • Kui Buri National Park
  • Mae On District, Chiang Mai
  • Mae Ramat District, Tak
  • Mae Sariang District, Mae Hong Son
  • Mae Sot District, Tak
  • Mae Taeng District, Chiang Mai
  • Mueang Chiang Mai District, Chiang Mai
  • Mueang Lampang District, Lampang
  • Na Haeo District, Loei
  • Nang Rong District, Buriram
  • Pak Thong Chai District, Nakhon Ratchasima
  • Pang Sida National Park
  • Phu Kradueng National Park
  • Phu Luang Wildlife Sanctuary
  • Sai Yok District, Kanchanaburi
  • Sakaerat Environmental Research Station
  • Salawin National Park
  • San Sai District, Chiang Mai
  • Song District, Phrae
  • Tha Song Yang District, Tak
  • Tha Yang District, Phetchaburi
  • Thung Chang District, Nan
  • Thung Yai Naresuan Wildlife Sanctuary
  • Umphang District, Tak
Range map of Fowlea piscator in Thailand