THE CENTER FOR NORTH AMERICAN HERPETOLOGY

Reptilia    Squamata (part-snakes)    Hydrophiidae  

Yellow-bellied Seasnake
Hydrophis platurus (Linnaeus, 1766)
HY-droh-fiss — PLAH-tur-us

SSAR 9th Edition Comments:
 Bessesen and Galbreath (2017, ZooKeys 686: 109–123) described a localized subspecies of H. platurus in Costa Rica that differs from the nominate race in size, coloration, locality, and habits. The nominate race occurs in the U.S. (Boundy, Jeff, Frank T. Burbrink, and Sara Ruane. 2025. Squamata (excluding lizards) – Snakes. Pages 38-54 in Kirsten E. Nicholson (Editor), Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding, 9th Edition. Society for the Study of Amphibians and Reptiles, Lawrence, Kansas. 87 pp.)

Range maps are based on curated specimens and provided gratis by CNAH.
(Created by Travis W. Taggart; Version: 2023.12.12.07.27.10)
Download GeoJSON polygon range file: - 4.72 MB

Province/State Distribution:
United States: California Hawaii

Taxonomic Etymology:
A pelagic sea snake with a distinctive flattened tail for swimming.
Hydrophis — From Greek hydro- (ὕδωρ), “water,” and ophis (ὄφις), “snake.” Refers to the aquatic (marine) lifestyle of the genus—“water snake.”
platurus — From Greek platys (πλατύς), “flat,” and oura (οὐρά), “tail.” Refers to the laterally compressed, paddle-like tail that aids in swimming—“flat-tailed.”

First instance(s) of published English names:
Bicolor Sea Snake (Hydrus platurus: Van Denburgh, John. 1922. The Reptiles of Western North America: An Account of the Species Known to Inhabit California and Oregon, Washinton, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora, and Lower California. Volume I. Lizards. California Academy of Sciences, San Francisco. 556pp.); Yellow-bellied Sea Snake (Pelamydrus platurus: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.);

Taxon Links:

  
Catalog of American Amphibians and Reptiles
  
The Reptile Database
  
NatureServe
  
iNaturalist
  
GenBank
  
USGS - Nonindigenous Aquatic Species Database

Selected References:
1766 Linné, Carl von (=Linneaus). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species cum characteribus, differentiis, synonymis, locis. Tomus I. [The system of nature through the three kingdoms of nature, according to classes, orders, genera, species with characters, differences, synonyms, places. Volume I.] Laurentii Salvii, Stockholm, Holmiae, Editio duodecima, reformata (12th Edition). 1-532pp.
1980 Pickwell, George V. and Wendy A. Culotta. Pelamis, P. platurus. Catalogue of American Amphibians and Reptiles (255):1-4
1983 Pickwell, George V., Robert L. Bezy, and John E. Fitch. Northern occurrences of the sea snake, Pelamis platurus, in the eastern Pacific, with a record of predation on the species. California Fish and Game 69(3):172-177
1999 Nardi, Irma, Renata Batistoni, Silvia Marracci, and Benedetto Lanza. Repetitive DNA components of the large Hydromantes genome: Phylogenetic and molecular aspects. Herpetologica 55(2):131-139
2013 Sanders, Kate L., Michael S.Y. Lee, Mumpuni, Terry Bertozzi, and Arne R. Rasmussen. Multilocus phylogeny and recent rapid radiation of the viviparous sea snakes (Elapidae: Hydrophiinae). Molecular Phylogenetics and Evolution 66:575-591
2017 Bessesen, Brooke L. and Gary J. Galbreath. A new subspecies of sea snake, Hydrophis platurus xanthos, from Golfo Dulce, Costa Rica. ZooKeys 686(2017):109-123

THE CENTER FOR NORTH AMERICAN HERPETOLOGY — Accessed: Friday 05 December 2025 15:55 CT