Banded Krait (Bungarus fasciatus)

Norman Lim sighted a Banded Krait (Bungarus fasciatus) on 21 May 2006, 11.25 pm on an offshore island. The snake was swimming from water and moving onto land, near the mangroves. This is unusual as it is a terrestrial species and is usually found in dry and forested areas (Lim & Lim, 1992; Cox et al., 1998). According to Lim & Lee (1989), Banded Kraits feed exclusively on other snakes, namely baby pythons, whip snakes, rat snakes and bronzebacks. However, Cox et al. (1998) claimed that they also feed on small mammals and lizards. These venomous snakes seem to be sluggish and docile in the day, but become active and aggressive at night (Lim & Lee, 1989; Cox et al., 1998).

Banded Kraits can grow up to 2 m (Lim & Lee, 1989; Lim & Lim, 1992; Cox et al., 1998), and has been recorded to live for over 11 years in captivity (Lim & Lee, 1989). They lay 4-14 eggs, and hatchlings are 25-40 cm (Lim & Lee, 1989; Cox et al., 1998). One individual in the Madras Snake Farm, India, was reported to have laid 12 eggs in early April, 6 of which hatched 61 days later (Lim & Lee, 1989).

This species occurs throughout Thailand, Malaysia, Singapore, and nearby regions (Cox et al., 1998).

From left to right: Left side of head; Left side of body; Dorsal side of tail.

* All photographs from Mr Norman Lim

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.

Updated Checklist of Singapore Snakes

The National Biodiversity Reference Centre has launched! I found and downloaded the "Reptile List". It is reviewed by Kelvin Lim (co-author of "A Guide To The Amphibians & Reptiles of Singapore") and updated on March 2006, so I suppose it can be considered to be the most updated and reliable checklist of Singapore snakes. There is now a total of 61 species. Many species are omitted while a few are included. There are also changes in scientific name of some species. Compare this to previous checklists.

Typhlopidae (Blind Snakes)
Ramphotyphlops braminus (Common Blind snake) (Daudin, 1803)
Typhlops muelleri (White-bellied Blind Snake) Schlegal, 1839

Cylindrophiidae (Bob-tailed Pipe Snakes)
Cylindrophis rufus (Red-tailed Pipe Snake) (Laurenti, 1768)

Xenopeltidae (Sunbeam Snakes)
Xenopeltis unicolor (Sunbeam Snake) Reinwardt, 1827

Pythonidae (Pythons)
Python reticulatus (Reticulated Python) (Schneider, 1801)

Acrochordidae (File Snakes)
Acrochordus granulatus (Banded File Snake) (Schneider, 1799)

Colubridae (Colubrid Snakes)
Ahaetulla fasciolata (Speckle-headed Whip Snake) (Fischer, 1885)
Ahaetulla prasina (Oriental Whip Snake) (F. Boie, 1827)
Boiga cynodon (Dog-toothed Cat Snake) (H. Boie, 1827)
Boiga dendrophila (Mangrove Snake or Gold-ringed Cat Snake) (F. Boie, 1827)
Boiga jaspidea (Jasper Cat Snake) (Duméril, Bibron & Duméril, 1854)
Calamaria lumbricoidea (Variable Reed Snake) H. Boie, 1827
Calamaria schlegeli (Pink-headed Reed Snake) (Duméril, Bibron & Duméril, 1854)
Cantoria violacea (Cantor’s Water Snake) (Girard, 1858)
Cerberus rynchops (Dog-faced Water Snake) (Schneider, 1799)
Chrysopelea paradisi (Paradise Tree Snake) H. Boie, in F. Boie, 1827
Chrysopelea pelias (Twin-barred Tree Snake) (Linnaeus, 1758)
Coelognathus flavolineatus (Common Malayan Racer) (Schlegal, 1837)
Coelognathus radiatus (Copperhead Racer) (F. Boie, 1827)
Dendrelaphis caudolineatus (Striped Bronzeback) (Gray, 1834)
Dendrelaphis cyanochloris (Blue Bronzeback) (Wall, 1921)
Dendrelaphis formosus (Elegant Bronzeback) (F. Boie, 1827)
Dendrelaphis pictus (Painted Bronzeback) (Gmelin, 1789)
Dryocalamus subannulatus (Malayan Bridle Snake) (Dumeril, Bibron & Duméril, 1854)
Dryophiops rubescens (Keel-bellied Whip Snake) (Gray, 1834)
Fordonia leucobalia (Crab-eating Water Snake) (Schlegal, 1837)
Gerarda prevostiana (Gerard’s or Yellow-lipped Water Snake) (Eydoux & Gervais, 1837)
Gongylosoma baliodeira (Orange-bellied Ringneck) F. Boie, 1827
Gonyosoma oxycephalum (Red-tailed Racer) (F. Boie, 1827)
Homalopsis buccata (Puff-faced Water Snake) (Linnaeus, 1758)
Lycodon capucinus(House Wolf Snake) (Linnaeus, 1758)
Lycodon subcinctus (Banded Wolf Snake) Boie, 1827
Macropisthodon rhodomelas (Blue-necked Keelback) (H. Boie, 1827)
Oligodon octolineatus (Striped Kukri Snake) (Schneider, 1801)
Oligodon purpurascens (Brown Kukri Snake) (Schlegal, 1837)
Oligodon signatus (Barred Kukri Snake) (Günther, 1864)
Pareas margaritophorus (White-Spotted Slug Snake) (Jan, 1866)
Psammodynastes pictus (Painted Mock Viper) Günther, 1858
Pseudorabdion longiceps (Dwarf Reed Snake) (Cantor, 1847)
Pytas carinata (Keeled Rat Snake) (Günther, 1858)
Pytas fusca (White-bellied Rat Snake) Gunther, 1864
Pytas korros (Indo-chinese Rat Snake) (Schlegal, 1837)
Sibynophis melanocephalus (Black-Headed Collared Snake) (Gray, 1834)
Xenelaphis hexagonotus (Malaysian Brown Snake) (Cantor, 1847)
Xenochrophis maculatus (Spotted Keelback) (Edeling, 1865)
Xenochrophis trianguligerus (Triangle Keelback) (F. Boie, 1827)
Xenochrophis vittatus (Striped Keelback) (Linnaeus, 1754)

Elapidae (Cobras, Coral Snakes, Kraits & Sea Snakes)
Aipysurus eydouxii (Marbled Sea Snake) (Gray, 1849)
Astrotia stokesii (Stoke’s Sea Snake) (Gray, 1846)
Bungarus fasciatus (Banded Krait) (Schneider, 1801)
Calliophis bivirgata (Blue Malayan Coral Snake) (F. Boie, 1827)
Calliophis intestinalis (Banded Malayan Coral Snake) (Laurenti, 1768)
Enhydrina schistosa (Beaked Sea Snake) (Daudin, 1803)
Hydrophis cyanocinctus (Blue-banded Sea Snake) (Daudin, 1803)
Hydrophis fasciatus (Western-banded Sea Snake) (Schneider, 1799)
Lapemis curtus (Short Sea Snake) Shaw, 1802
Laticauda colubrina (Yellow-lipped Sea Krait) (Schneider, 1799)
Naja sumatrana (Equatorial Spitting Cobra) F. Müller, 1887
Ophiophagus hannah (King Cobra) (Cantor, 1836)

Crotalidae (Pit-vipers)
Trimeresurus wagleri (Wagler’s Pit-viper) (H. Boie, 1827)
Trimeresurus purpureomaculatus (Shore or Mangrove Pit-viper) (Gray, 1830)

Shore Pit Viper (Trimeresurus purpureomaculatus)

This Shore Pit Viper (Trimeresurus purpureomaculatus) crossed our (Me, Chan Kwok Wai, and Norman Lim) path in Pasir Ris Park Mangrove Swamp on 7 May 2006 at about 9 pm. This is an arboreal species (Lim & Lee, 1989; Lim & Lim, 1992) and is often observed on low bushes (Cox et al., 1998) but was, surprisingly, moving on soft mud on that day. They spend much of their time coiled up in trees and shrubs where they ambush small mammals and birds (Lim & Lee, 1989). These nocturnal snakes also feed on lizards, frogs, and other small animals (Cox et al., 1998). In captivity, this viper will take mice and day-old chicks (Lim & Lee, 1989).

These venomous snakes have a reputation of being bad-tempered and quick to strike (Lim & Lee, 1989; Lim & Lim, 1992; Cox et al., 1998). Fortunately, the one we encountered did not show any of that nature.

Shore Pit Vipers give live birth to 7 to 15 young of about 24 cm in length (Lim & Lee, 1989; Cox et al., 1998). Lim & Lee (1989) reported that captive snakes from Thailand gave birth in the months of April and May. An adult reaches a length of about 1 m (Lim & Lee, 1989; Lim & Lim, 1992).

This species inhabits southern Thailand, Peninsula Malaysia, Singapore, Tenasserim and Sumatra (Cox et al., 1998).

From left to right: Front of head; Dorsal side of head; Left side of body.

* 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.

You can HISSS too!

You can Help in Saving Singapore Snakes by doing the 3 Ss!

SHOOT ... do not KEEP
We either love or hate snakes. Those who love snakes are always tempted to keep them as pets. Try keeping photographs instead. Shoot them with your cameras!



SHOO ... do not KILL
Singaporeans always ask "Can eat or not?" whenever we see anything that moves. For snakes, we are more concerned about "Got poison (=venom) or not?". Some of us are too trigger-happy and prefer to adopt a "kill first, find out later" policy when it comes to snakes. We must know that few snakes in Singapore are venomous enough to harm or kill us, and most snakes are so shy that they will 'run' for their life with a simple shoo.

SLOG
Click here to understand what this is all about.

Cantor's Water Snake (Cantoria violacea)

The first time I met this beautiful snake was back in 2001, while helping Harold Voris and Daryl Karns in their survey of homalopsine snakes in Pasir Ris Park Mangrove Swamp. I chanced upon this species again at the same place on 4 September 2005, 12.25 am. It has a very slender elongate body and can reach lengths of 120 cm (Rooij, 1917). This species has a wide distribution and is found in Burma, Thailand, Peninsula Malayasia, Singapore, Sumatra, Borneo, and Timor (Rooij, 1917; Frith & Boswell, 1978). The diet records of this species was first published only in 2002, about 145 years after its description! Voris and Murphy (2002) discovered that Cantoria violacea feeds on the giant mangrove snapping shrimp Alpheus microrhychus. Incredibly, there is almost nothing else we know about this snake!

From left to right: Dorsal side of head; Left side of head; Dorsal side of body.

* All photographs from Mr Lim Swee Cheng

REFERENCES

De Rooij, N., 1917. The reptiles of the Indo-Australian archipelago (II Ophidia). EJ Brill Ltd. Leiden, p. 190-191.

Frith, C. B. & Boswell, J., 1978. Cantor's Water Snake, Cantoria violaecea Girard; a Vertebrate New to the Fauna of Thailand. Natural History Bulletin of Siam Society (Bangkok) 27: 187-189.

Voris, H.K. and J. C. Murphy. 2002. The prey and predators of homalopsine snakes. Journal of Natural History, 36(13):1621-1632.

Brahminy Blind Snake (Ramphotyphlops braminus)

We (Me, Chan Kwok Wai and Lim Swee Cheng) were on an open field near International Business Park on 7 May 2006 at about 4pm, when Kwok Wai lifted a small rock and found a pair of these tiny snakes. Ever since then, we realised that Brahminy Blind Snakes (Ramphotyphlops braminus), indeed, can be found on soil under rocks pretty easily. In fact, these creatures are so common in flowerpots that they are also known as Flowerpot Blind Snakes. That is how this species is being transported to all over the world, including places (e.g. Hawaii) that do not have any native snakes. According to Cox et al. (1998), This species is found throughout Thailand, Peninsula Malaysia, Singapore, Africa, the Middle East, the remainder of tropical Asia and parts of eastern temperate Asia, islands across the Pacifics, Mexico, and the United States. These snakes occur from sea level up to 1,640 m (Cox, et al., 1998).

The most interesting fact about Brahminy Blind Snakes is that it is the only known parthenogenetic snake species; all individuals are females and males are unknown (Lim & Lim, 1992; Cox, et al., 1998)! Females produce clutches of 1-7 eggs, measuring 2 x 6 mm, without fertilization; all eggs develop into females (Lim & Lee, 1989; Cox, et al., 1998).

According to Lim and Lee (1989), Brahminy Blind Snakes feed on soft-bodied insects. Lim and Lim (1992) claimed that they feed on minute soil-dwelling invertebrates. Cox et al. (1998) claimed that these snakes feed mainly on the larvae of ants and termites.

These non-venomous snakes are very common, nocturnal, and the adults can reach up to only 15 cm in length (Lim & Lee, 1989; Lim & Lim, 1992; Cox et al., 1998).






From left to right: Dorsal side of head; Left side of head; Dorsal side of body; Ventral side of body; Dorsal side of tail' Ventral side of trail

* Photographs from Mr Chan Kwok Wai and Lim Swee Cheng

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.

Checklist of Singapore Snakes

Lim and Lee (1989) listed 57 species of snakes that can be found in Singapore. The checklist of Singapore snakes compiled by Lim and Chou (1990) increased the total number of species to 93, by adding another 37 species to the list in Lim and Lee (1989) and omitting the dubious record Enhydris plumbea. Lim and Lim (1992) have a similar list, but with an additional species (Enhydris enhydris), further increasing the total number of snake species in Singapore to 94. The conservation status of 14 snakes were listed in Wee and Ng (1994).

() – doubtful records; _ – almost certainly introduced; R – rare; V – vulnerable.

Boidea (Pythons)
Python reticulatus (Reticulated Python) (Schneider, 1801) 1, 2, 3
Python curtus (Short or Blood Python) Schlegal, 1872 (1), 2, 3

Acrochordidae (File Snakes)
Acrochordus granulatus (Banded File Snake) (Schneider, 1799) 1, 2, 3
Acrochordus javanicus (Javan File Snake or Elephant Trunk Water Snake) Hornstedt, 1787 (1), 2, 3

Xenopeltidae (Sunbeam Snakes)
Xenopeltis unicolor (Sunbeam Snake or Iridescent Earth Snake) Reinwardt, 1827 1, 2, 3

Aniliidae (Pipe Snakes)
Cylindrophis rufus (Red-tailed Pipe Snake) (Laurenti, 1768) 1, 2, 3

Typhlopidae (Blind Snakes)
Ramphotyphlops braminus (Common Blind snake) (Daudin, 1803) 1, 2, 3
Typhlops muelleri (White-bellied or Diard’s Blind Snake) Schlegal, 1839 1, 2, 3
Typhlops lineatus (Striped Blind Snake) Boie, 1827 2, 3

Colubridae (Colubrine Snakes)
Elaphe flavolineata (Common Malayan Racer) (Schlegal, 1837) 1, 2, 3
Elaphe radiata (Copperhead Racer) (F. Boie, 1827) 1, 2, 3
Elaphe porphyracea (Red Mountain Racer) (Cantor, 1839) 2, 3
Elaphe taeniura (Striped Racer or Cave-dwelling Rat Snake) Cope, 1861 (1), 2, 3
Gonyosoma oxycephala (Red-tailed Racer) (F. Boie, 1827) 1, 2, 3, V
Pytas korros (Indo-chinese Rat Snake) (Schlegal, 1837) 1, 2, 3
Pytas mucosus (Banded Rat Snake) (Linnaeus, 1766) (1), (2), 3
Pytas carinatus (Keeled Rat Snake) (Günther, 1858) 1, 2, 3
Zaocys fuscus (White-bellied Rat Snake) Gunther, 1864 2, 3
Sibynophis melanocephalus (Black-Headed Collared Snake) (Gray, 1834) 1, 2, 3
Lycodon aulicus (House Snake) (Linnaeus, 1758) 1, 2, 3
Lycodon subcinctus (Banded Wolf Snake) Boie, 1827 2, 3, R
Dryocalamus subannulatus (Saddled Tree snake) (Dumeril, Bibron & Duméril, 1854) 2, 3, V
Oligodon octolineatus (Striped Kukri Snake) (Schneider, 1801) 1, 2, 3
Oligodon purpuracens (Brown Kukri Snake) (Schlegal, 1837) 1, 2, 3, V
Oligodon signatus (Barred Kukri Snake) (Günther, 1864) 2, 3, V
Calamaria lumbricoidea (Variable Reed Snake) H. Boie, 1827 1, 2, 3
Calamaria albiventer (Red-bellied Reed Snake) (Gray, 1835) 2, 3
Calamaria schlegeli schlegeli (Pink-headed Reed Snake) (Duméril, Bibron & Duméril, 1854) 1, 2, 3
Calamaria prakkei (Prakke’s Reed Snake) Lidth de Jeude, 1893 (2), 3
Pseudorhabdion longiceps (Dwarf Reed Snake) (Cantor, 1847) 1, 2, 3
Liopeltis baliodeirus (Orange-bellied Ringneck) F. Boie, 1827 1, 2, 3, V
Liopeltis tricolor (Tricoloured Ringneck) (Schlegal, 1837) 2, 3
Dendrelaphis pictus (Painted Bronzeback) (Gmelin, 1789) 1, 2, 3
Dendrelaphis formosus (Elegant Bronzeback) (F. Boie, 1827) 1, 2, 3
Dendrelaphis caudolineatus (Striped Bronzeback) (Gray, 1834) 1, 2, 3
Xenelaphis hexagonotus (Malayan Brown Snake) (Cantor, 1847) 1, 2, 3
Chrysopelea paradisi (Paradise Tree Snake) H. Boie, in F. Boie, 1827 1, 2, 3
Chrysopelea pelias (Twin-barred Tree Snake) (Linnaeus, 1758) 1, 2, 3, V
Gonyophis margaritatus (Rainbow Tree Snake) (Peters, 1871) 2, 3
Ahaetulla prasina (Oriental Whip Snake) (F. Boie, 1827) 1, 2, 3
Ahaetulla fasciolata (Speckle-headed Whip Snake) (Fischer, 1885) 2, 3, V
Dryphiops rubescens (Keel-bellied Whip Snake) (Gray, 1834) 1, 2, 3, V
Boiga dendrophila (Mangrove Snake or Gold-ringed Cat Snake) (F. Boie, 1827) 1, 2, 3
Boiga cynodon (Dog-toothed Cat Snake) (H. Boie, 1827) 1, 2, 3, V
Boiga jaspidea (Jasper Cat Snake) (Duméril, Bibron & Duméril, 1854) 1, 2, 3, V
Boiga drapiezii (White-spotted Cat Snake) (Boie, 1827) (1), 2, 3
Psammodynastes pictus (Painted Mock Viper) Günther, 1858 2, 3, V
Cerberus rynchops (Dog-faced Water Snake) (Schneider, 1799) 1, 2, 3
Homalopsis buccata (Puff-faced Water Snake) (Linnaeus, 1758) 1, 2, 3
Fordonia leucobalia (Crab-Eating Snake) (Schlegal, 1837) 2, 3
Enhydris enhydris (Rainbow Water Snake) (Schneider, 1799) (1), 3
Gerarda prevostiana (Gerard’s Water Snake) (Eydoux & Gervais, 1837) 2, 3
Cantoria violacea (Cantor’s Water Snake) (Girard, 1858) 2, 3
Bitia hydroides (Keel-bellied Water Snake) Gray, 1842 2, 3
Xenochrophis piscator (Chequered Keelback) (Schneider, 1799) (1), 2, 3
Xenochrophis vittatus (Striped Keelback) (Linnaeus, 1754) (1), 2, 3
Xenochrophis trianguligerus (Triangle Keelback) (F. Boie, 1827) 2, 3
Xenochrophis maculatus (Spotted Keelback) (Edeling, 1865) 2, 3, V
Amphiesma petersi (Peter’s Keelback) (Boulenger, 1893) 2, 3
Rhabdophis subminiatus (Red-necked Keelback) (Schlegal, 1837) (1), 2, 3
Macropisthodon rhodomelas (Blue-necked Keelback) (H. Boie, 1827) 1, 2, 3

Elapidae (Cobras, Kraits & Coral Snakes)
Naja sumatrana (Black Spitting Cobra) F. Müller, 1887 1, 2, 3
Ophiophagus hannah (King Cobra) (Cantor, 1836) 1, 2, 3, V
Bungarus fasciatus (Banded Krait) (Schneider, 1801) 1, 2, 3
Bungarus candidus (Malayan Krait) (Linnaeus, 1758) 1, 2, 3
Maticora bivirgata (Blue Malayan Coral Snake) (F. Boie, 1827) 1, 2, 3
Maticora intestinalis (Banded Malayan Coral Snake) (Laurenti, 1768) 1, 2, 3
Calliophis gracilis (Spotted Coral Snake) Gray, 1835 2, 3

Hydrophiidae (Sea Snakes)
Laticauda colubrina (Amphibious Sea Snake) (Schneider, 1799) 1, 2, 3
Aipysurus eydouxii (Marbled Sea Snake) (Gray, 1849) 2, 3
Enhydrina schistosa (Beaked Sea Snake) (Daudin, 1803) 1, 2, 3
Leioselasma cyanocincta (Blue-banded Sea Snake) (Daudin, 1803) 1, 2, 3
Leioselasma spiralis (Tiger Sea Snake) (Shaw, 1802) 2, 3
Thalassophis anomalus (Anomalous Sea Snake) Schmidt, 1852 2, 3
Kolpophis annandalei (Annandale’s Sea Snake) (Laidlaw, 1901) 2, 3
Kerilia jerdoni (Jerdon’s Sea Snake) (Gray, 1849) 2, 3
Praescutata viperina (Olive Sea Snake) (Schmidt, 1852) 1, 2, 3
Acalyptophis peronii (Eyelash Sea Snake) (Duméril, 1853) 2, 3
Hydrophis klossi (Kloss’s Sea Snake) Boulenger, 1912 2, 3
Hydrophis fasciatus (Barred Sea Snake) (Schneider, 1799) 2, 3
Hydrophis melanosoma (Black-banded Sea Snake) Günther, 1864 2, 3
Hydrophis caerulescens (Blue Sea Snake) (Shaw, 1802) 2, 3
Hydrophis brookii (Brooke’s Sea Snake) Günther, 1872 2, 3
Hydrophis ornatus (Ornate Sea Snake) (Gray, 1842) 2, 3
Hydrophis torquatus (Grey Sea Snake) Günther, 1864 2, 3
Lapemis curtus (Short Sea Snake) Shaw, 1802 2, 3
Astrotia stokesii (Stoke’s Sea Snake) (Gray, 1846) 2, 3
Microcephalophis gracilis (Small-headed Sea Snake) (Shaw, 1802) 2, 3
Pelamis platyurus (Yellow-bellied Sea Snake) (Linnaeus, 1766) 2, 3

Viperidae (Vipers)
Trimeresurus wagleri (Wangler’s Pit Viper) (H. Boie, 1827) 1, 2, 3
Trimeresurus purpureomaculatus (Shore or Mangrove Pit Viper) (Gray, 1830) 1, 2, 3
Trimeresurus sumatranus (Sumatran Pit Viper) (Raffles, 1822) (1), 2, 3
Trimeresurus popeiorum (Pope’s Pit Viper) Smith 1937 (2), 3
Trimeresurus monticola (Mountain Pit Viper) Günther, 1864 (2), 3


References:

1. Lim, F. L. K. & Lee, M. T. M., 1989. Fascinating Snakes of Southeast Asia – an Introduction. Tropical Press, Kuala Lumpur, p. 115-117.

2. Lim, K. K. P. & Chou, L. M., 1990. The herpetofauna of Singapore. In: Chou, L. M. & Ng, P. K. L. (Ed.), Essays in Zoology. Papers commemorating the 40th Anniversary of the Department of Zoology, National University of Singapore, p. 53-55.

3. Lim, K. K. P. & Lim, F. L. K., 1992. A Guide To The Amphibians & Reptiles Of Singapore. Singapore Science Centre, p. 144-149.

4. Ng., P. K. L. & Wee, Y. C., 1994. The Singapore Red Data Book – Threatened Plants & Animals Of Singapore. The Nature Society (Singapore), p. 331.