• VENOM: Very mild - no known danger

  • PREVALENCE: Not common

  • ACTIVE PERIOD: Active both day and night

  • KEY ID FEATURES: Olive to brown body with black markings, white belly with black stripes, ~60 cm when mature

  • BEHAVIOR: Aquatic, may be found near marsh water, not aggressive but can bite and if handled

  • OTHER: Can be mistaken with other water snakes but not easily confused with venomous species



Mangrove Water Snakes are dark brown or olive with black markings on top and white to yellow bellies with black stripes running horizontally. They have a rounded head with strong jaws helpful for hunting fish. Nostrils and eyes evolved on top of the head due to their aquatic nature. Generally not exceeding 60 cm when mature. Smooth scales and soft feel to the underbelly. Though technically venomous, reactions are rare in humans and usually consist of minor localized swelling and in more extreme cases mild nausea or dizziness.


Active both day and night Mangrove Water Snakes come out to hunt fish in mangrove and tidal water bodies. Active periods may coincide with tides. Not quick to bite or musk when approached or handled and despite being mildly venomous they are not considered dangerous to humans though it should be noted that envenomations can cause mild symptoms including nausea and localized swelling. 


Found largely Lantau near marshes and tidal mud flats the Mangrove Water Snake is a less common snakes to encounter in Hong Kong.


NO SNAKE SHOULD EVER BE HANDLED BY ANYONE BUT EXPERTS: Can be mistaken for some other aquatic snakes but generally not confused with dangerously venomous species.


IMPORTANT: Most snakes can be found to have significant variance in coloration and pattern even within the same species. There can also be extreme differences in appearance from juveniles to adults so it is important to never assume you have properly identified a snake.