I (together with Ria Tan, Chan Kwok Wai, and Charlene Yeong) visited a freshwater pond in Sungei Buloh Wetland Reserve on 19 May 2006, at about 8 pm, and found that the Puff-faced Water Snakes (Homalopsis buccata) are particularly abundant. They are probably the only other snakes in Singapore, besides the Dog-faced Water Snakes (Cerberus rynchops), to appear in high densities. These nocturnal snakes are more or less confined to freshwater habitats, such as rivers, ponds, and canals (Lim & Lee, 1989; Lim & Lim, 1992; Cox et al., 1998). We sighted both juveniles and adults, which have slightly different scale colourations and patterns. Females give birth to 2-20 young of about 230 mm in a litter (Lim & Lee, 1989; Cox et al., 1998). This species can grow to a little over 1 m in length (Lim & Lee, 1989; Lim & Lim, 1992; Cox et al., 1998).
We also witnessed an adult and a juvenile fighting over a prey (Tilapia?)! The tinier one, as expected, lost the tug-of-war. Puff-faced Water Snakes are also known to consume frogs (Cox et al., 1998). Due to their appetite for freshwater fish, these snakes are considered pests in ornamental fish farms (Lim & Lee, 1989; Lim & Lim, 1992).
There are mixed accounts on the temperament of this mildly-venomous species. Lim & Lee (1989) claimed that it has a vicious temper and will bite severely if roughly handled. But according to Lim & Lim (1992), this is one gentle snake!
Puff-faced Water Snake inhabits most of Southeast Asia, including southern Thailand, Malaysia, and Singapore (Cox et al., 1998).
From left to right: Front of head; Left side of head; Dorsal side of head; Ventral side of head; Dorsal side of body; Ventral side of body; Ventral side of tail and anal plate.
* All photographs from Mr Chan Kwok Wai.
REFERENCES
Cox, M. J., van Dijk, P. P., Nabhitabhata, J. & Thirakhupt, K., 1998. A photographic guide to snakes and other reptiles of Peninsula Malaysia, Singapore and Thailand. New Holland Publishers (UK) Ltd, p. 12.
Lim, F. L. K. & Lee, M. T. M., 1989. Fascinating Snakes of Southeast Asia – an Introduction. Tropical Press, Kuala Lumpur, p. 30.
Lim, K. K. P. & Lim, F. L. K., 1992. A Guide To The Amphibians & Reptiles Of Singapore. Singapore Science Centre, p. 147.
I (together with Ria Tan, Chan Kwok Wai, and Charlene Yeong) visited a freshwater pond in Sungei Buloh Wetland Reserve on 19 May 2006, at about 8 pm, and found that the Puff-faced Water Snakes (Homalopsis buccata) are particularly abundant. They are probably the only other snakes in Singapore, besides the Dog-faced Water Snakes (Cerberus rynchops), to appear in high densities. These nocturnal snakes are more or less confined to freshwater habitats, such as rivers, ponds, and canals (Lim & Lee, 1989; Lim & Lim, 1992; Cox et al., 1998). 
We also witnessed an adult and a juvenile fighting over a prey (Tilapia?)! The tinier one, as expected, lost the tug-of-war. Puff-faced Water Snakes are also known to consume frogs (Cox et al., 1998). Due to their appetite for freshwater fish, these snakes are considered pests in ornamental fish farms (Lim & Lee, 1989; Lim & Lim, 1992). 
