Thai National Parks

Reptiles of Thailand

Species of Thailand

Crab-eating water snake

Thai: งูปลาหัวเทา, ngu plaa hua thao

Binomial name: Fordonia leucobalia, Hermann Schlegel, 1837

The aquatic snake Fordonia leucobalia is known by the common names crab-eating water snake and white-bellied mangrove snake. It is a common resident of mangrove swamps and tropical tidal wetlands from Southeast Asia to the coasts of Northern Australia.

Individual F. leucobalia reach up to a meter in length, and are brown or gray in color with a white belly. There is significant color variation. Some have spots. The anatomy reflects the snake's water-living lifestyle: the eyes are located atop the head, and the nostrils have valves that close when the snake dives.

The snake eats small prey that live in its habitat, such as frogs and small fish, and it specializes in crabs, hence its name. Like other homalopsines, F. leucobalia bears live young.

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Scientific classification

Fordonia leucobalia

Common names

  • German: Krebs-Wassertrugnatter
  • English:
    • Crab-eating (water) snake
    • White-bellied mangrove snake
  • Thai:
    • งูปลาหัวเทา, ngu plaa hua thao
    • งูกินเปี้ยว, ngu gin pieow


  • Fordonia leucobalia, John C. Murphy & Harold K. Voris (2014)
  • Fordonia leucobalia, Nguyen Van Sang et al. (2009)
  • Fordonia leucobalia, Harold Cogger (2000)
  • Fordonia leucobalia, Merel J. Cox et al. (1998)
  • Fordonia leucobalia, Ulrich Manthey & Wolfgang Grossmann (1997)
  • Fordonia leucobalia, Malcolm Arthur Smith (1943)
  • Fordonia varabilis, William John Macleay (1878)
  • Fordonia papuensis, William John Macleay (1877)
  • Fordonia bicolor, William Theobald (1868)
  • Hemiodontus chalybaeus, Giorgio Jan (1863)
  • Hemiodontus leucobalia, André Marie Constant Duméril & Gabriel Bibron (1854)
  • Fordonia unicolor, John Edward Gray (1849)
  • Fordonia leucobalia, John Edward Gray (1842)
  • Homalopsis leucobalia, Hermann Schlegel (1837)

Conservation status

Least Concern (IUCN3.1)

Least Concern (IUCN3.1)

No photo for this species yet

Distribution map of Crab-eating water snake, Fordonia leucobalia in Thailand
  • Ko Samui District, Surat Thani
  • Krabi Coast
  • Phuket Coast
  • Satun Coast
  • Trang Coast

Range map of Fordonia leucobalia 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 and Parinya Pawangkhanant for their help with many range data.

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