Yellow-bellied sea snake

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Yellow-bellied sea snake
Yellow-bellied sea snake

Least Concern  (IUCN 3.1)[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Hydrophis
Species:
H. platurus
Binomial name
Hydrophis platurus
(Linnaeus, 1766)
Yellow-bellied sea snake range[2]
Synonyms
List
  • Anguis platura Linnaeus, 1766
  • Hydrus bicolor
    Schneider
    , 1799
  • Hydrophis platuraLatreille, 1801
  • Pelamis platurosDaudin, 1803
  • Pelamis bicolorDaudin, 1803
  • Hydrophis pelamis Schlegel, 1837
  • Pelamis ornata Gray, 1842
  • Pelamis platurusStoliczka, 1872
  • Hydrus platurusBoulenger, 1890
  • Pelamydrus platurusSchmidt & Davis, 1941
  • Pelamis platura – Böhme, 2003[3][4]
Yellow form from the Golfo Dulce on the Pacific coast of Costa Rica

The yellow-bellied sea snake (Hydrophis platurus) is a

tropical oceanic waters around the world except for the Atlantic Ocean. For many years, it was placed in the monotypic genus Pelamis, but recent molecular evidence indicates it lies within the genus Hydrophis
.

Taxonomy

In 1766, Linnaeus published the original description of the yellow-bellied sea snake, naming it Anguis platura (Anguis meaning snake). In 1803, François Marie Daudin created the new genus Pelamis and assigned this species to it, referring to it as Pelamis platuros. In 1842, Gray described what he thought was a new species and called it Pelamis ornata (subsequently P. ornata became a synonym of P. platura). The commonly used genus name Pelamis is derived from the Ancient Greek word for "tunny fish", which presumably refers to the habitat or what Daudin thought they ate. The specific name platurus is a combination of the Ancient Greek words platys "flat" and oura "tail", referring to the flattened tail. The word Pelamis is a feminine noun and means young or small tunny fish. In 1872, Stoliczka introduced the name Pelamis platurus (still the most used scientific name by scientists today), but used the incorrect ending -us instead of -a which a feminine noun requires.[5] A few recent examples exist of scientists' beginning to use the grammatically correct name Pelamis platura, e.g., Bohme 2003 and the Reptile Database with its page headed Pelamis platura (Linnaeus, 1766), which includes an extensive synonymy of the different scientific names which have been used for the yellow-bellied sea snake.[6] The same rules apply for the most recent taxonomic name of Hydrophis platurus.

To further complicate the

phylogenetic relationships.[7]

Other common names are yellowbelly sea snake or pelagic sea snake.[citation needed]

Evolution

Sea snakes are a monophyletic group (Hydrophiinae) that diverged from the front-fanged Australasian venomous snakes (Elapidae) about 10 million years ago.[8][9] The yellow-bellied sea snake is a part of the rapidly radiating Hydrophis group.[10]

Description

cutaneous gas exchange for prolonging dive times.[12][13][14] This species can uptake up to 33% of its oxygen requirements through the skin while diving and swimming at the surface of the water.[15] Sea snakes also have a special salt gland located in the lower jaw that was formerly believed to filter out salt from the surrounding seawater[16] but has been found not to be used for that purpose, as sea snakes drink fresh water only.[17]

See
snake scales
for terminology used here

Morphology

The body of this snake is compressed, with the posterior less than half the diameter of the neck; the body scales are juxtaposed, subquadrangular in shape, and in 23–47 rows around the thickest part of the body; ventral scales, 264–406 in number, are very small and, if distinct, divided by a latitudinal groove, but usually are indistinguishable from adjacent body scales. The head is narrow, with an elongated snout; head shields are entire, nostrils are superior, and nasal shields are in contact with one another; the prefrontal scale is in contact with second upper labial; one or two preoculars, two or three postoculars, and two or three small anterior temporals are present; seven or eight upper labials are found, with four or five below the eye, but separated from the border by a subocular. Colors of the snake are variable, but most often distinctly bicolored, black above, yellow or brown below, with the dorsal and ventral colors sharply demarcated from one another; ventrally, there may be a series of black spots or bars on the yellow or brown background, or the yellow may extend dorsally so there is only a narrow middorsal black stripe, or a series of black crossbars.[18] Total length for males is up to 720 mm (28 in), for females up to 880 mm (35 in); tail length for males is up to 80 mm (3.1 in), females up to 90 mm (3.5 in).

Distribution and habitat

Hydrophis platurus xanthos

The yellow-bellied sea snake is one of the most widely distributed snakes in the world.[19] It is completely pelagic and is often observed on oceanic drift lines, using surface currents and storms to move around the ocean.[20] Their distribution appears to be largely determined by favourable water temperatures, oceanic currents and recent formation of land bridges that have blocked farther dispersal.

The yellow-bellied sea snake has an extensive distribution covering the entire tropical

Southwest Australia, including records at beaches near metropolitan areas.[24] It is also reported from Christmas Island and Cocos (Keeling) Islands (Australia).[25]

The yellow-bellied sea snake requires a minimum of 16–18 °C (60.8 to 64.4 °F) to survive, long-term.

El Niño, among other severe weather events, possibly creating unusually strong, new ocean currents that transport the snakes far off-course.[30][31][32] In October 2015, beached yellow-bellied sea snakes were reported and photographed on beaches in Ventura County, California, well outside their normal range, for the first time in 30 years.[30] A few months later, in January 2016, a stranded individual was found in Coronado, California, washed-up on Coronado Beach's north end (better known as Dog Beach), just south of Naval Air Station North Island (NASNI). The specimen was subsequently transported to and examined at the Scripps Institute of Oceanography, La Jolla.[33]

The yellow-bellied sea snake is the only sea snake to have been found in the Atlantic Ocean, although only in limited circumstances. The yellow-bellied sea snake's occurrence into the Atlantic is not considered a part of its native range, but rather a dispersal from its native Pacific range.[34]

The yellow-bellied sea snake has been found in all the countries of Africa's eastern coast and all eastern islands, like Djibouti, Eritrea, Kenya, Madagascar, Mauritius, Mayotte, Mozambique, Réunion, Seychelles, Somalia, South Africa and Tanzania.[25] On the African Atlantic coast they have been reported to occur in the Benguela Current, with specimens found along the coasts of South Africa and Namibia.[35][36]

The yellow-bellied sea snake has also been found in the Colombian Caribbean four separate times, making it the only sea snake to be found in the Caribbean Sea. However these occurrences are believed to be the result of human activity, be it ship discharge, intentional release or via the Panama Canal, as it is not considered a part of their native range. This is due to the land bridge between North and South America (Isthmus of Panama), which formed from about 10 million years ago to 3 million years ago[37] (i.e., continental drift), acting as a dispersal barrier and preventing entry into the Caribbean Sea from the Pacific Ocean. The man-made Panama Canal has not made a crossing of the isthmus possible presumably because it is fresh water.[38]

Due to the wide distribution of the species and relative lack of dispersal barriers, it has been assumed that individuals from different localities represent a single breeding population (i.e., high gene flow). However, a study that used haplotype networks in two populations from Costa Rica suggests that shallow genetic population structure exists, which reflects variation in colour patterns (brown and yellow in Golfo de Papagayo and completely yellow in Golfo Dulce).[39]

Behaviour

Contrary to past beliefs, sea snakes require fresh water to survive and the yellow-bellied sea snake drinks precipitation that forms on the surface of sea water.[40] This species has been reported to survive severe dehydration of up to 7 months during seasonal drought.[41]

Yellow-bellied sea snakes breed in warm waters; they are

ovoviviparous with a gestation period around 6 months. According to Ditmars, females bear live young in tidal pools.[42] They move poorly on land due to their smaller belly scales that form a ventral keel.[13] They are sometimes observed in large aggregations of thousands on the surface of the water in oceanic drift lines, which has been proposed as a strategy to catch prey.[43] They hunt by floating on the surface of the water to attract pelagic fish that are seeking shelter; prey are captured via a backwards swimming motion and rapid lunge of the jaws.[20] The ability to swim backwards is an unusual and distinguishing characteristic of this species.[24] Heatwole proposed that these snakes find their prey by sensing the vibration generated by fish movement.[44]

Venom

The venom of this species is highly potent, like that of other

sea snakes.[45] Bites are rare and the most common victims are fishermen who try to get them out of fishing nets.[46] The subcutaneous LD50 of the venom is 0.067 mg/kg and the venom yield per bite is 1.0–4.0 mg.[47][48] Yellow-bellied sea snake venom contains several different neurotoxins and two other isotoxins.[49]

Antivenom

Sea snake venom can cause damage to skeletal muscle with consequent

Enhydrina schistosa) antivenom.[50][51] If that preparation is not available, tiger snake or polyvalent antivenom should be used. No deaths have been recorded from bites in Australian waters.[52][53] The E. schistosa antivenom was tested specifically on Pelamus platurus, and it effectively neutralised the venom.[54]

Cited references

  1. doi:10.2305/IUCN.UK.2017-2.RLTS.T176738A115883818.en. Retrieved 12 November 2021.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  2. ^ 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". IUCN Red List of Threatened Species. 2010: e.T176738A115883818.
  3. ^ Boulenger, G.A. 1896. Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ)... Trustees of the British Museum (Natural History). London. pp. 266–268.
  4. ^ The Reptile Database. www.reptile-database.org.
  5. .
  6. ^ Pelamis platura at the Reptarium.cz Reptile Database. Accessed May 2008
  7. S2CID 207552237
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  13. ^ .
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  16. .
  17. ^ "The Sad Tale of the Thirsty, Dehydrated Sea Snake". Phenomena. 18 March 2014. Archived from the original on March 19, 2014.
  18. ^ (M.A. Smith, 1943: 476–477, gives more complete descriptions of the color pattern variants).
  19. PMID 22087300
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  20. ^ a b Heatwole, Harold (1993). Fauna of Australia: Family Hydrophiinae. Canberra: AGPS. p. 15.
  21. .
  22. ^ Palermo, Elizabeth (December 28, 2015). "Venomous Sea Snake Washes Up on California Beach, Surprising Scientists". Scientific American. Retrieved 2016-03-30.
  23. ^ Liptow, J. (1999). "Pelamis platura". Animal Diversity Web. University of Michigan. Retrieved 17 December 2022.
  24. ^ .
  25. ^ a b Guinea, M. (15 February 2009). "IUCN Red List of Threatened Species: Hydrophis platurus". IUCN Red List of Threatened Species.
  26. ^ Dunson and Ehlert 1971.
  27. Fairfax New Zealand
    . 4 January 2012. Retrieved 26 April 2012.
  28. ^ Natural History Information Centre. "Natural History Questions". Auckland, New Zealand: Auckland War Memorial Museum. Q. Are there any snakes in New Zealand?. Archived from the original on 29 November 2014. Retrieved 26 April 2012.
  29. Wikidata Q58629017
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  30. ^ a b "Blame El Niño for poisonous sea snake found on Ventura County beach". Los Angeles Times. 17 October 2015. Retrieved 2015-10-25.
  31. ^ "Yellow-bellied Sea Snake – Australian Museum". australianmuseum.net.au. Retrieved 2016-03-30.
  32. ^ "El Nino brings sea snake to California's coast". CNN. 17 October 2015. Retrieved 2015-10-25.
  33. ^ "Yellow-bellied Sea Snake from Coronado Beach, Coronado, San Diego, California". iNaturalist. 12 January 2016.
  34. ^ Harvey B Lillywhite, Coleman M Sheehy, Harold Heatwole, François Brischoux, David W Steadman; "Why Are There No Sea Snakes in the Atlantic?", BioScience, Volume 68, Issue 1, 1 January 2018, Pages 15–24, https://doi.org/10.1093/biosci/bix132
  35. JSTOR 1442198
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  36. ^ Also see references in The Living Shores of Southern Africa, Margo and George Branch, pp. 130–131, Macmillan South Africa (Publishers), Johannesburg and "Snake versus Man" Johan Marais, pp. 50–51, C. Struik Publishers, Cape Town.
  37. ^ "North and South America Came Together Much Earlier Than Thought: Study". NBC News. Retrieved 2016-03-30.
  38. ^ Hernández-Camacho, J.I. & Álvarez-León, Ricardo & Renjifo-Rey, J.M.. (2006). Pelagic sea snake Pelamis platurus (Linnaeus, 1766) (Reptilia: Serpentes: Hydrophiidae) is found on the Caribbean Coast of Colombia. Mem. Fund. La. Salle Cien. Nat.. 164. 143-152.
  39. PMID 22659201
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  40. .
  41. .
  42. ^ Schmidt, K.P. & D.D. Davis. 1941. Field Book of Snakes of the United States and Canada. G.P. Putnam's Sons. New York. p. 280.
  43. S2CID 86115673
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  44. .
  45. ^ "SnakeBiteTemplate3.pmd" (PDF).
  46. ISSN 1477-8939
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  47. ^ LD50 value of venomous snakes Archived 2012-02-01 at the Wayback Machine
  48. ^ [1] LD stands for "Lethal dose".
  49. ^ Mori, Nobuhiro & Ishizaki, Hiroyuki & Tu, Anthony. (1989). "Isolation and Characterization of Pelamis platurus (Yellow-bellied Sea Snake) Postsynaptic Isoneurotoxin". The Journal of Pharmacy and Pharmacology. 41. 331-4. 10.1111/j.2042-7158.1989.tb06466.x.
  50. .
  51. .
  52. ^ https://www.flyingdoctor.net/IgnitionSuite/uploads/docs/snakebite.pdf Management of snake bites in Australia and Papua New Guinea. Accessed May 2008
  53. ^ http://www.emedicine.com/emerg/topic543.htm Accessed May 2008
  54. ^ http://www.ajtmh.org/cgi/content/abstract/23/1/135 Published 1973. Accessed May 2008.

Other sources

  • Ditmars, R.L. 1936. The Reptiles of North America. Doubleday, Doran & Co. New York. 476 pp.
  • Hecht, M. K.; Kropach, C.; Hecht, B. M. (1974). "Distribution of the yellow-bellied sea snake Pelamis platurus, and its significance in relation to the fossil record". Herpetologica. 30: 387–395.
  • Kropach, C. 1975 The yellow-bellied sea snake, Pelamis, in the eastern Pacific. pp. 185–213 in: Dunson, W., ed., The Biology of Sea Snakes. Univ. Park Press, Baltimore, xi + 530 pp.
  • Smith, M.A. 1943. The Fauna of British India, Ceylon and Burma, including the Whole of the Indo-Chinese Sub-region. Reptiles and Amphibians. Vol. III. – Serpentes. Taylor & Francis. London. 583 pp.

External links