Hydrophis platurus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Elapidae

Scientific Name: Hydrophis platurus (Linnaeus, 1766)
Common Name(s):
English Yellow-bellied Sea Snake, Pelagic Sea Snake
French Serpent marin jaune
Spanish Serpiente Marina Amarilla
Anguis platura Linnaeus, 1766
Pelamis platura (Linnaeus, 1766)
Pelamis platurus (Linnaeus, 1766) [orth. error]
Taxonomic Notes: Previously known as Pelamis platura. Sanders et al. (2012), in a phylogeny of the hydrophines, showed that Pelamis was nested within Hydrophis, necessitating the transfer of P. platurus to Hydrophis. The placement within Hydrophis was confirmed by Rezaie-Atagholipour et al. (2016).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2017
Date Assessed: 2009-02-15
Assessor(s): Guinea, M., Lukoschek, V., Cogger, H., Rasmussen, A., Murphy, J., Lane, A., Sanders, K. Lobo, A., Gatus, J., Limpus, C., Milton, D., Courtney, T., Read, M., Fletcher, E., Marsh, D., White, M.-D., Heatwole, H., Alcala, A., Voris, H. & Karns, D.
Reviewer(s): Livingstone, S.R., Elfes, C.T., Polidoro, B.A. & Carpenter, K.E. (Global Marine Species Assessment Coordinating Team)
This is the most widely distributed sea snake species. There are some threats, but none thought to be major and the population is most likely stable. This species is listed as Least Concern.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is very widespread in the tropical parts of the Pacific and Indian Oceans between the 18-20º C isotherms (Dunson and Ehlert 1971, Graham et al. 1971). It is known from the coasts of eastern Africa, north to the Arabian Gulf, east along the Asian coast of the Indian Ocean to the Pacific Ocean, northward to Japan and eastward to the western coasts of the Americas (Heatwole 1999).

Currents occasionally carry the snakes into temperate waters, but these are almost certainly far from their breeding and feeding waters.
Countries occurrence:
American Samoa; Australia; Bahrain; Bangladesh; Cambodia; China; Christmas Island; Cocos (Keeling) Islands; Colombia; Costa Rica; Djibouti; Ecuador (Ecuador (mainland), Galápagos); El Salvador; Eritrea; Fiji; French Polynesia; Guatemala; Honduras; India (Andaman Is., Nicobar Is.); Indonesia; Iran, Islamic Republic of; Iraq; Japan; Kenya; Kiribati; Korea, Democratic People's Republic of; Korea, Republic of; Kuwait; Madagascar; Malaysia; Mauritius; Mayotte; Mexico; Micronesia, Federated States of ; Mozambique; Myanmar; Nauru; New Caledonia; Niue; Oman; Pakistan; Palau; Panama; Papua New Guinea; Philippines; Pitcairn; Qatar; Réunion; Samoa; Seychelles; Singapore; Solomon Islands; Somalia; South Africa; Sri Lanka; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Tokelau; Tonga; Tuvalu; United Arab Emirates; United States (Hawaiian Is.); United States Minor Outlying Islands (Howland-Baker Is., Johnston I., US Line Is.); Vanuatu; Viet Nam; Wallis and Futuna; Yemen
FAO Marine Fishing Areas:
Indian Ocean – western; Indian Ocean – eastern; Pacific – southeast; Pacific – western central; Pacific – eastern central; Pacific – northwest; Pacific – southwest
Additional data:
Lower depth limit (metres):10
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Although there is no specific population information about the species, it is thought to be stable.

This is a fairly common species throughout the waters of the Indian sub-continent, occasionally washed ashore during rough weather, which is probably due to its pelagic habits. For the same reason, it is also rarely encountered as bycatch in fishing operations (A. Lobo pers. comm.).

Kropach (1975) marked 961 individuals of this species in the Bay of Panama over a one year period. None were recaptured during the period. About a year later, one was recaptured in the Bay of Panama and three were collected off the coast of Mexico.

Estimating population size for this species is difficult, as the range is very broad over several oceans. In addition, the distribution pattern of Hydrophis platurus is very clumped. Visual surveys from boats are probably the most suitable technique for estimating population size. The unique habits and colouration of H. platurus mean that it is unlikely to be confused with other species (Marsh et al. 1993).
Current Population Trend:Stable
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:The species is the most pelagic of the sea snakes, occurring in the open ocean well away from coasts and reefs. However, a small individual (total length = 230 mm) found in a mangrove swamp (Minton 1966) suggests that the species may occasionally occur in inter-tidal habitats. This species eats only fish (Klawe 1963) that mistakenly seek shelter beneath the motionless snake that resembles drifting wood. Consequently they forage to a depth of only about 2 m (Kropach 1975). This species is usually found in the 0-10 m range of the water column (Cogger 2007). This is the only marine snake not associated with the benthic community (Marsh et al. 1993).

In the open ocean, the snakes often occur in large numbers in association with long lines of debris. These "slicks" form in calm seas and consist variously of debris, foam and scum brought together by converging water currents. In some areas, such as the Gulf of Panama in the eastern Pacific Ocean, the slicks can vary in width from 1 to 300 m and stretch for many kilometres. Several thousand snakes may be associated with a single slick. It is not clear whether the snakes actively swim to the slicks or whether they are carried into them passively (Kropach 1971, 1975). The only obvious activity that is performed by the snakes in the slicks is feeding and knotting. Other activities that might benefit from large aggregations, such as mating, have not been observed. Females are significantly larger than males (Kropach 1975).

The minimum snout-vent length at birth is about 22 cm and sexual maturity is reached as a length of 50 cm and 62.5 cm for males and females respectively (Marsh et al. 1993).

Congregatory:Congregatory (and dispersive)

Threats [top]

Major Threat(s): There are no known major threats to this species. Minor threats may include bycatch in squid fisheries (M. Guinea pers. comm. 2009), ghost fishing nets, and pollution, including oil spills.

Conservation Actions [top]

Conservation Actions: There are no species-specific conservation measures in place.

No sea snake species is currently listed by CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora).

Amended [top]

Amended reason: This species was originally assessed under the genus Pelamis, but it is now transferred to Hydrophis, hence the need for this amended assessment. The species' name in the text has also been updated.

Classifications [top]

9. Marine Neritic -> 9.1. Marine Neritic - Pelagic
10. Marine Oceanic -> 10.1. Marine Oceanic - Epipelagic (0-200m)

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.4. Unintentional effects: (large scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

9. Pollution -> 9.2. Industrial & military effluents -> 9.2.1. Oil spills
♦ timing:Past, Unlikely to Return    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

Bibliography [top]

Cogger, H. 2007. Marine Snakes. In: T. Vickey and S. Keable (eds), Description of Key Species Groups in the East Marine Region, pp. 80-94. Australian Museum.

Dunson, W.A. and Ehlert, G.W. 1971. Effects of temperature, salinity, and surface water flow on distribution of the sea snake Pelamis. Limnology and Oceanography 16(6): 845-853.

Graham, J.B., Rubinoff, I. and Hecht, M.K. 1971. Temperature physiology of the sea snake Pelamis platurus: an index of its colonization potential in the Atlantic Ocean. Proceedings of the National Academy of Sciences 68: 1360-1363.

Greer, A.E. 2006. Encyclopedia of Australian Reptiles. Available at:

Guinea, M.L. 2007. Marine Snakes: Species Profile for the North-western Planning Area. Report for the Department of the Environment, Water, Heritage and the Arts. Charles Darwin University, Darwin, NT.

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).

IUCN. 2017. The IUCN Red List of Threatened Species. Version 2017-2. Available at: (Accessed: 14 September 2017).

Klawe, W.L. 1963. Inter-American Tropical Tuna Commission Bulletin 6: 447-540.

Kropach, C. 1971. Another color variety of the sea snake Pelamis platurus from Panama Bay. Herpetologica 27(3): 326-327.

Kropach, C. 1975. The yellow-bellied sea snake, Pelamis, in the eastern Pacific. In: W.A. Dunson (ed.), The Biology of Sea Snakes, pp. 185-213. University Park Press, Baltimore, Maryland.

Marsh, H., Corkeron, P.J., Limpus, C.J., Shaughnessy, P.D. and Ward, T.M. 1993. Conserving marine mammals and reptiles in Australia and Oceania. In: C. Moritz and J. Kikkawa (eds), Conservation Biology in Australia and Oceania, pp. 225-244. Surrey, Beatty & Sons, Chipping Norton.

Minton, S.A. 1966. A contribution to the herpetology of West Pakistan. Bulletin of the American Museum of Natural History 134: 27-184.

Rezaie-Atagholipour, M., Ghezellou, P., Hesni, M.A., Dakhteh, S.M.H., Ahmadian, H. and Vidal, N. 2016. Sea snakes (Elapidae, Hydrophiinae) in their westernmost extent: an updated and illustrated checklist and key to the species in the Persian Gulf and Gulf of Oman. ZooKeys 622: 129–164. doi: 10.3897/zookeys.622.9939.

Sanders, K.L., Lee, M.S.Y., Mumpuni, Bertozzi, T. and Rasmussen, A.R. 2012. Multilocus phylogeny and recent rapid radiation of the viviparous sea snakes (Elapidae: Hydrophiinae). Molecular Phylogenetics and Evolution 66(3): 575-591.

Citation: Guinea, M., Lukoschek, V., Cogger, H., Rasmussen, A., Murphy, J., Lane, A., Sanders, K. Lobo, A., Gatus, J., Limpus, C., Milton, D., Courtney, T., Read, M., Fletcher, E., Marsh, D., White, M.-D., Heatwole, H., Alcala, A., Voris, H. & Karns, D. 2017. Hydrophis platurus (amended version of 2010 assessment). The IUCN Red List of Threatened Species 2017: e.T176738A115883818. . Downloaded on 19 June 2018.
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