Venom effects and medical significance are different from toxicity rankings. Do not handle a snake on the basis of this summary.
A comparatively large head and robust hindbody distinguish the body form from extremely thin-necked sea snakes. Broad dark bars or diamond-shaped blotches cross a pale upper surface. Its atlas account links 3 named island or island-group records to the source literature.
OccurrenceSupported
Islands named3
Natural history5 sourced topics
References3
Literature updated 2026-10-07 · Editorial review pending
Coastal island outlines are geographic context, not a mapped marine range.
Appearance & identification
A comparatively large head and robust hindbody distinguish the body form from extremely thin-necked sea snakes. Broad dark bars or diamond-shaped blotches cross a pale upper surface.
Species-level database summary; literature review, not expert validation.
The cited account does not establish population-wide variation or the conditions at every Philippine locality.
Reproduction
The species account records live-bearing reproduction, using the term ovoviviparous. A verified Philippine litter-size range and reproductive calendar are not established here.
Reproductive mode reported for this named species.
Mode alone does not establish litter or clutch size, seasonal timing, or captive husbandry requirements.
Ecology & habitat
The account records a marine habitat. Island names on the map identify reported coastal areas; they are not land occupancy or a boundary of the species’ marine range.
Species-level database summary; literature review, not expert validation.
The cited account does not establish population-wide variation or the conditions at every Philippine locality.
Taxonomic context
Hydrophis ornatus is retained in the atlas’s dated checklist under Elapidae. The authority is (GRAY 1842). Earlier names and the original source notes are preserved below for comparison.
Literature documented · Checklist identity and nomenclatural trail
Checklist verified 2026-09-05; not a newly revised taxonomic backbone.
Historical names can cover different biological concepts; synonyms should not be used to transfer records automatically.
Across the archipelago
Where this species is recorded
PhilippinesN ↑
Coastal records: blue outlines
Blue outlines locate coastal records, not land occupancy or marine range boundaries.
Philippine distribution
Documented places
Manila Bay, Panay and Gigantes Sur.
3 named islands / island groups
Select an island to read its distribution record and sources. Uncoloured islands are not evidence of absence.
Distribution record & sources
Indian Ocean (Pakistan, Sri Lanka, India (Kerala), Indonesia (Borneo), Papua New Guinea, Malaysia, Vietnam, Myanmar,
South Chinese Sea (China: Coasts of Guangxi, Guangdong, Hainan, Taiwan, Shandong), Japan (Ryukyu),
Persian Gulf (Oman, United Arab Emirates, Iran) through Indian Ocean
Indoaustralian Archipelago, Philippines, Gulf of Thailand,
Australia (Western Australia, Northern Territory, Queensland, New South Wales)
New Caledonia/Loyalty Islands, Solomon Islands [McCoy 2000]
godeffroyi: Vietnam, Japan,
maresinensis: Japan, China; Type locality: “Ishigaki Shima, Ryu Kyu Archipelago”
Type locality: not given
Venomous · Effects not yet summarised in this atlas
Observe from a distance. Do not handle, corner or capture a snake to identify it. An incomplete venom account is not evidence that a species is safe to handle.
After a suspected snakebite, keep the person still and arrange urgent medical care. Avoid tight tourniquets, cutting, suction and unproven remedies. Do not wait to identify the snake before seeking help.
Distribution reviewed against cited source (p. 464). Manila Bay, Panay and Gigantes Sur.
Islands named
Luzon, Panay, Gigantes Sur
Range noteCountry/island text is not a range polygon or locality record.
Source distribution statement
Indian Ocean (Pakistan, Sri Lanka, India (Kerala), Indonesia (Borneo), Papua New Guinea, Malaysia, Vietnam, Myanmar,
South Chinese Sea (China: Coasts of Guangxi, Guangdong, Hainan, Taiwan, Shandong), Japan (Ryukyu),
Persian Gulf (Oman, United Arab Emirates, Iran) through Indian Ocean
Indoaustralian Archipelago, Philippines, Gulf of Thailand,
Australia (Western Australia, Northern Territory, Queensland, New South Wales)
New Caledonia/Loyalty Islands, Solomon Islands [McCoy 2000]
godeffroyi: Vietnam, Japan,
maresinensis: Japan, China; Type locality: “Ishigaki Shima, Ryu Kyu Archipelago”
Type locality: not given
Knowledge coverage
EndemismResearch pending
EcologyLiterature documented
VenomVenomous Effects not yet summarised in this atlasDetailed research: Research pending
Venomous!
Synonymy: According to GOLAY et al. 1993, Hydrophis ornatus godeffroyi has been synonymized with Hydrophis ornatus ornatus. COGGER 2000 questions the validity of ocellatus without giving specific reasons. By contrast, Hydrophis ornatus ocellatus has been treated as valid species more recently, but does not occur in Australia (Rasmussen et al. 2014).
Habitat: marine.
Distribution: For a map see Sindaco et al. 2013. Not in Hong Kong fide Francis 2021
Type species: Aturia ornata GRAY 1842: 61 is the type species of the genus Aturia GRAY 1842, now considered as a synonym of Hydrophis.
Genome: Ludington et al. 2023.
References attached to this record
2026
The Reptile Database — species checklist, 17 June 2026
Hydrophis ornatus — The Reptile Database species account
Uetz, P.; Hallermann, J. et al. (editors)
Public species fields consulted for bounded biological summaries. Primary sources quoted within the database were not independently examined unless explicitly stated. The catalogue name may differ from the current source title.