''Aipysurus duboisii'', also known commonly as Dubois' sea snake and the reef shallows sea snake, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

of highly

venomous snake Venomous snakes are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow or g ...

in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...

Hydrophiinae Hydrophiinae is a subfamily of venomous snakes in the family Elapidae. It contains most sea snakes and many genera of venomous land snakes found in Australasia, such as the taipans (''Oxyuranus''), tiger snakes (''Notechis''), brown snakes ('' ...

of the family

Elapidae Elapidae (, commonly known as elapids ; grc, ἔλλοψ ''éllops'' "sea-fish") is a family of snakes characterized by their permanently erect fangs at the front of the mouth. Most elapids are venomous, with the exception of the genus Emydoce ...

. Its geographic range includes

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

and the northern, eastern and western coastal areas of

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

, that is the

Coral Sea The Coral Sea () is a marginal sea of the South Pacific off the northeast coast of Australia, and classified as an interim Australian bioregion. The Coral Sea extends down the Australian northeast coast. Most of it is protected by the Fre ...

Arafura Sea The Arafura Sea (or Arafuru Sea) lies west of the Pacific Ocean, overlying the continental shelf between Australia and Western New Guinea (also called Papua), which is the Indonesian part of the Island of New Guinea. Geography The Arafura S ...

Timor Sea The Timor Sea ( id, Laut Timor, pt, Mar de Timor, tet, Tasi Mane or ) is a relatively shallow sea bounded to the north by the island of Timor, to the east by the Arafura Sea, and to the south by Australia. The sea contains a number of reefs ...

and

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by ...

. It lives at depths up to 80 meters (262 feet) in

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of Colony (biology), colonies of coral polyp (zoology), polyps held together by calcium carbonate. Most coral reefs are built from stony corals, wh ...

flats, sandy and

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...

y sediments which contain

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and '' Chlorophyta'' (green) macroalgae. Seaweed species such as ...

, invertebrates and corals or

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throu ...

s that can serve as shelter. It preys upon

moray eel Moray eels, or Muraenidae (), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are f ...

s and various fish that live on the seafloor, up to 110 cm (3.6 feet) in size. ''A. duboisii'' is

viviparous Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the ...

, giving birth to live young rather than laying eggs.''Aipysurus duboisii'' Bavay, 1869
SeaLifeBase site: UBC - Canada It displays medium aggressiveness, i.e., will bite if provoked, but not spontaneously. The fangs are 1.8 mm long, which are relatively short for a snake, and the venom yield is 0.43 mg. ''Aipysurus duboisii'' is a

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of dayli ...

species, meaning that it is most active at

dawn Dawn is the time that marks the beginning of twilight before sunrise. It is recognized by the appearance of indirect sunlight being scattered in Earth's atmosphere, when the centre of the Sun's disc has reached 18° below the observer's ...

and

dusk Dusk occurs at the darkest stage of twilight, or at the very end of astronomical twilight after sunset and just before nightfall.''The Random House College Dictionary'', "dusk". At predusk, during early to intermediate stages of twilight, enou ...

. It is the most venomous sea snake, and one of the top three most venomous snakes in the world. Fry, Bryan, Deputy Director, Australian Venom Research Unit, University of Melbourne (March 9, 2002)
50 – list of the available data and sorted by route of injection "">"Snakes Venom LD₅₀ – list of the available data and sorted by route of injection "
venomdoc.com. (archived) Retrieved October 14, 2013.The Australian venom research unit (August 25, 2007)

.

University of Melbourne The University of Melbourne is a public research university located in Melbourne, Australia. Founded in 1853, it is Australia's second oldest university and the oldest in Victoria. Its main campus is located in Parkville, an inner suburb ...

. Retrieved October 14, 2013.

Etymology

The specific name, ''duboisii'', is in honor of

Belgian Belgian may refer to: * Something of, or related to, Belgium * Belgians, people from Belgium or of Belgian descent * Languages of Belgium, languages spoken in Belgium, such as Dutch, French, and German *Ancient Belgian language, an extinct languag ...

naturalist

Charles Frédéric Dubois Charles Frédéric Dubois (28 May 1804 – 12 November 1867) was a Belgian naturalist. He was the author of ''Planches colorées des oiseaux de l’Europe'' ("Color plates of the birds of Europe") and ''Catalogue systématique des Lépidoptères ...

Description

Adults of ''A. duboisii'' grow up to 148 cm (4.86 feet) in total length (including tail) but usually to around 80 cm (2.6 feet). The head is slightly wider than the neck with

nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

s on its upper part and nasals contacting each other. Eyes are separated from

supralabial scales In reptiles, the supralabial scales, also called upper-labials, are those scales that border the mouth opening along the upper jaw. They do not include the median scaleWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates ...

by a row of large subocular scales. Dorsal scales are usually smooth, but sometimes have a small keel or small knobs. Individuals vary significantly in color and body pattern. The tail is relatively long; the chin and throat have lighter color than rest of the body.

Venom

The

acute toxicity Acute toxicity describes the adverse effects of a substance that result either from a single exposure or from multiple exposures in a short period of time (usually less than 24 hours). To be described as ''acute'' toxicity, the adverse effect ...

snake venom Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is injected by unique fangs during a bite, whereas some species are a ...

is conventionally tested on laboratory animals and is evaluated in terms of the

median lethal dose In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is ...

(LD₅₀), that is, the dose required to kill half the members of a tested population divided by the weight of the tested animal. The LD₅₀ depends on the animal. Rabbits are about twice as sensitive to sea snake venom as mice, and fish and frogs are even more susceptible. The LD₅₀ for

subcutaneous injection Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion. A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, c ...

of ''A. duboisii'' venom into mice is 0.044 mg/kg of body weight. This makes ''A. duboisii'' the most venomous sea snake tested, and the third most venomous snake overall, behind the inland taipan (''Oxyuranus microlepidotus'', LD₅₀=0.025 mg/kg) and the

eastern brown snake The eastern brown snake (''Pseudonaja textilis''), often referred to as the common brown snake, is a species of highly venomous snake in the family Elapidae. The species is native to eastern and central Australia and southern New Guinea. It ...

(''Pseudonaja textilis'', LD₅₀=0.036 mg/kg).Heatwole, p. 115.Gopalakrishnakone P (1994)
''Sea Snake Toxinology''
Singapore: National University of Singapore Press. . p. 98.

References

Bibliography

* Heatwole, Harold (1999)
''Sea Snakes''
Australian Natural History Series. Sydney: University of New South Wales Press. 148 pp. . {{Taxonbar, from=Q2707083 duboisii Snakes of Australia Reptiles of Indonesia Snakes of New Caledonia Reptiles of Papua New Guinea Reptiles described in 1869 Snakes of New Guinea Taxa named by Arthur René Jean Baptiste Bavay

Etymology

Description

Venom

See also

References

Bibliography