Cerberus rynchops 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Homalopsidae

Scientific Name: Cerberus rynchops
Species Authority: (Schneider, 1799)
Common Name(s):
English Asian Bockadam, Bockadam Snake, Dog-faced Water Snake, New Guinea Bockadam
Cerberus rhynchops (Schneider, 1799) [orth. error]
Homalopsis rhynchops (Schneider, 1799)
Hydrus rynchops Schneider, 1799
Python rhynchops (Schneider, 1799)
Taxonomic Notes: Based on morphology and DNA evidence, there are possible grounds for dividing this species into three: a South Asian species extending from India to Phuket, a Southeast Asian species from Phuket to Philippines and Indonesia, and a Palau species occurring in Palau exclusively.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2010
Date Assessed: 2009-02-15
Assessor(s): Murphy, J.
Reviewer(s): Livingstone, S.R., Elfes, C.T., Polidoro, B.A. & Carpenter, K.E. (Global Marine Species Assessment Coordinating Team)
This species has a wide distribution and is abundant in many of its localities across the range. This species thrives in human areas such as fishing villages. There has been historic collection of this species for skins but this apparently no longer happens. This species has therefore been listed as Least Concern.

Geographic Range [top]

Range Description: This species as currently defined occurs in coastal South Asia, peninsular India, Sri Lanka, Bangladesh, Myanmar, the Andaman Islands, eastward to the coastal areas of the Indochinese and Malaysian Peninsulas, southwards into Indonesia and eastwards to Palau and Micronesia (Murphy 2007).
Countries occurrence:
Australia; Bangladesh; Cambodia; India; Indonesia; Malaysia; Myanmar; Palau; Philippines; Singapore; Sri Lanka; Thailand; Timor-Leste; Viet Nam
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This species is abundant in many localities across its range (Murphy 2007). It is particularly abundant in areas of human fishing and fish cleaning activities (Murphy 2007). Jayne et al. (1988) had an 80,000 m² study site at Muar, Peninsular Malaysia, and estimated 374-1,396 individuals. The sub-adult population was estimated to be one to three snakes per linear metre of shoreline.
Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: The species inhabits a variety of coastal habitats including mangrove forests, mudflats, tidal creeks, estuaries, rivers and sometimes coral reefs. It is most frequently found in salt and brackish waters but may venture into freshwater. It also appears to be tolerant of human activity. This species is nocturnal (Murphy 2007). The species feeds mostly on small fish and possibly crustaceans (Heatwole 1999). The South Asian populations feed on frogs (A. Lobo pers. comm. 2009).
Systems: Freshwater; Marine

Use and Trade [top]

Use and Trade: This species was historically traded and used for skins in the Philippines. It is currently no longer used for this purpose in the Philippines, but it is unclear whether harvests occur in Indonesia.

Threats [top]

Major Threat(s): This species has historically been collected for its skin in the Philippines (Gaulke 1998). But, it is no longer being collected for skins in the Philippines (J. Gatus pers. comm. 2009). In 1993 it was reported that 775,000 skins were found in the leather trade in Indonesia (Lilley 1993). It is unclear if there is continued use of the species for leather in Indonesia.

Conservation Actions [top]

Conservation Actions: This species is listed on Appendix II of CITES. In India, this species is protected under the Indian Wildlife Act (1972), due to its historic trade as skin.

Classifications [top]

1. Forest -> 1.7. Forest - Subtropical/Tropical Mangrove Vegetation Above High Tide Level
suitability: Marginal  
5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
suitability: Suitable  
9. Marine Neritic -> 9.6. Marine Neritic - Subtidal Muddy
suitability: Suitable  
9. Marine Neritic -> 9.10. Marine Neritic - Estuaries
suitability: Suitable  
12. Marine Intertidal -> 12.4. Marine Intertidal - Mud Flats and Salt Flats
suitability: Suitable  
12. Marine Intertidal -> 12.7. Marine Intertidal - Mangrove Submerged Roots
suitability: Suitable  
15. Artificial/Aquatic & Marine -> 15.3. Artificial/Aquatic - Aquaculture Ponds
suitability: Suitable  

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
  Included in international legislation:Yes
  Subject to any international management/trade controls:Yes
5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.1. Intentional use: (subsistence/small scale)
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.2. Intentional use: (large scale)
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

♦  Wearing apparel, accessories
 National : ✓  International : ✓ 

Bibliography [top]

Gaulke, M. 1998. Utilization and conservation of lizards and snakes in the Philippines. Mertensiella 9: 137-142.

Heatwole, H. 1999. Sea Snakes. Krieger Publishing Company, Malabar, Florida.

IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.4). Available at: (Accessed: 27 October 2010).

Jayne B.C., Voris, H.K, Heang, K.B. 1988. Diet, feeding behavior, growth, and numbers of a population of Cerberus rynchops (Serpentes:Homalopsinae) in Malaysia. Fieldiana, Zoology, New Series 50: 3-15.

Karns, D.R., Voris, H.K. and Goodwin, T.G. 2002. Ecology of Australasian rear-fanged water snakes (Serpentes: Homalopsinae) in the Pasir Ris Mangrove Forest, Singapore. The Raffles Zoological Bulletin 50(2): 487-498.

Lilley, G. 1993. The use of reptiles as a product. The Reptilian Magazine 1: 12-14.

Murphy, J.C. 2007. Homalopsid Snakes: Evolution in the Mud. Krieger Publishing Company, Malabar, Florida.

Citation: Murphy, J. 2010. Cerberus rynchops. The IUCN Red List of Threatened Species 2010: e.T176680A7282653. . Downloaded on 28 November 2015.
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