Fig. 1. Dorsal view of entire carcass of the Rainbow Water Snake.
Fig. 2. View of the snake’s head and anterior section, showing the large wound in the neck.
Photographs by Ivan W.M. Kwan
Rainbow Water Snake (Enhydris enhydris) at Sungei Buloh Wetland Reserve
Location, date and time: Singapore Island, Sungei Buloh Wetland Reserve, pond at Wetland Centre; 14 November 2014; 0940 hrs.
Observation: A fresh carcass measuring about 40 cm total length was found at the edge of the pond (Fig. 1). Apart from a large wound in the neck region (indicated by an arrow in Fig. 2), no other external injury was
Remarks: The carcass has been collected and deposited in the Zoological Reference Collection (ZRC) of the Lee Kong Chian Natural History Museum at the National University of Singapore. It is not known what caused the wound on the subject, or if it had succumbed from the injury. The Rainbow Water Snake is believed to be a recent introduction to Singapore, possibly imported as accidental stowaways among aquatic and marsh vegetation by plant nurseries in the area (Lim & D’Rozario, 2009). It has been recorded from the north-western corner of Singapore Island since 2008 by Lim & D’Rozario (2009), Chua (2010: 101, misidentified as Xenopeltis unicolor) and Baker & Thomas (2013).
Baker, N. & N. Thomas, 2013. Rainbow Mud Snakes at Kranji Marsh. Singapore Biodiversity Records. 2013: 47.
Chua E. K., 2010. Wetlands in a City. The Sungei Buloh Wetland Reserve. Simply Green, Singapore. 176 pp
Lim, K. K. P. & V. D’Rozario, 2009. The Rainbow Mud Snake, Enhydris enhydris (Schneider) [Reptilia: Squamata: Homalopsidae] in Singapore. Nature in Singapore. 2: 9–12.
Fig. 1. Dorsal view of ZRC 2.7085.
Fig. 2. Ventral view of ZRC 2.7085, with the retrieved food item, a Clarias leiacanthus.
Photographs by Tan Heok Hui
A food item of the Blackwater Mud Snake (Phytolopsis punctata)
Location, date and time: Singapore Island, Central Catchment Nature Reserve, Nee Soon swamp forest; 22 November 2014.
Observation: A large adult female example of 63.5 cm snout-vent length and 72.0 cm total length was found dead in a submerged trap used for an on-going biodiversity survey. Upon dissection, a Forest Walking Catfish (Clarias leiacanthus) of 13.6 cm standard length (from snout tip to tail base) was retrieved. The pectoral spine of the ingested catfish had pierced through the gut wall of the snake, but not yet through the skin. The snake is presumed to have died either from asphyxiation or from the puncture of its gut wall by its ingested prey.
Remarks: The occurrence of the Blackwater Mud Snake in Singapore is first recorded by Thomas et al. (2014) based on two smaller examples obtained at the same general area. The natural history of this apparently rare species is virtually unknown, except it is typically associated with acid-water and peat swamps (Murphy, 2007: 162, as Enhydris punctata). Clarias leiacanthus appears to be the first recorded food item of this snake. The present specimen, catalogued as ZRC.2.7085, is deposited in the Zoological Reference Collection of the Lee Kong Chian Natural History Museum at the National University of Singapore.
Murphy, J. C., 2007. Homalopsid snakes: Evolution in the mud. Krieger Publishing Company, Malabar, Florida, USA. 249 pp.
Thomas, N., T. Li, W. Lim & Y. Cai, 2014. New record of the blackwater mud snake in Singapore. Singapore Biodiversity Records. 2014: 309-310.
This week, I’ll be featuring some of the many specimens representing Singapore wildlife that were on display at VivoCity last weekend as part of the Festival of Biodiversity.
Three species of water snakes that can be found in Singapore’s mangroves:
Upper Left: Crab-eating Water Snake (Fordonia leucobalia); This snake hunts crabs that are sometimes too large for it to swallow whole. In these cases, it will coil around the crab, pins it down against the mud, and then pulls the crab’s legs off and swallows them one after another. If the crab’s body is still too large to be swallowed, it will be left behind. This is one of the few snakes that actually breaks its prey into smaller pieces first, instead of swallowing the entire animal whole.
Lower Left: Yellow-lipped Water Snake (Gerarda prevostiana); This snake also hunts crabs, except that it specifically targets crabs that have just moulted and are still relatively soft-bodied. After the crab is caught, the snake coils around it and uses its mouth to simply tear the soft-shelled crab into smaller pieces, swallowing each chunk whole. The crab is completely helpless and can’t defend itself, as the exoskeleton hasn’t hardened yet.
Right: Dog-faced Water Snake (Cerberus schneiderii); This snake feeds on fishes, which it catches by either lying in wait amongst mangrove roots and waiting for a fish to swim past, or by carefully inspecting any holes and crevices for small fish hiding within. The venom that this snake produces plays a role in quickly subduing and immobilising the fishes that it hunts.
These are some of the stories about Singapore’s wildlife that were shared at the Festival of Biodiversity 2014, which was held over the weekend.