''Rhabdophis'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

s in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Natricinae The Natricinae are a subfamily of colubroid snakes, sometimes referred to as a family (Natricidae). The subfamily comprises 36 genera. Members include many very common snake species, such as the European grass snakes, and the North American wa ...

of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Colubridae Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...

Species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

in the genus ''Rhabdophis'' are generally called keelback snakes, and are found primarily in

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

. The best-known species is '' Rhabdophis tigrinus''; few other species have been studied in detail.

Toxicity

Colubrid snakes are often thought of as completely harmless, but there are a handful of notable exceptions, including some species of ''Rhabdophis''. Bites from both ''Rhabdophis tigrinus'' and ''Rhabdophis subminiatus'' have caused cases of severe envenomation. There are several reports of fatal bites from ''R. tigrinus''. Between 1971 and 2020, 5 of 43 ''R. tigrinus'' bites in Japan were fatal, all of which occurred in cases not treated with antivenom. Antivenom is manufactured by the Japan Snake Institute and is an effective treatment for ''R. tigrinus'' bites, but is an unapproved drug. The venom is highly hemorrhagic. While the term "poisonous snake" is often incorrectly used for a wide variety of

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 ...

s, some species of ''Rhabdophis'' are in fact poisonous as well as venomous. Many species of ''Rhabdophis'' have specialized nuchal glands on the back of the neck that are used to store cardiotonic steroids (bufadienolides) sequestered from their diet, mostly from toads but also from firefly larvae. ''Rhabdophis'' are resistant to the toxic effects of these chemicals. This is different from their venom, which is produced in oral glands and is not known to contain bufadienolides or other sequestered toxins. Female ''Rhabdophis tigrinus'' can pass sequestered chemicals to their offspring, both by deposition in egg yolk and by transfer across the egg membranes within the oviduct, late in gestation.

Recent taxonomic changes

In 2018, ''Balanophis ceylonensis'' and three of the four species in the genus ''Macropisthodon'' were reassigned to ''Rhabdophis'' on the basis of three genes indicating a common ancestor for all species possessing nuchal glands. At least two species, ''“R”. conspicillatus'' and ''“R”. chrysargos'', are more distantly related and might be assigned to other genera in the future. The same analysis suggested that ''Rhabdophis'' might contain several undescribed species.

Species

These

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

are recognized as being valid:. www.reptile-database.org. *'' Rhabdophis adleri'' *'' Rhabdophis akraios'' – Singalang keelback *'' Rhabdophis angeli'' – Angel's keelback *'' Rhabdophis auriculatus'' – white-lined water snake *'' Rhabdophis barbouri'' – Barbour's water snake Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Rhabdophis barbouri'', p. 16; ''R. swinhonis'', p. 258). *'' Rhabdophis bindi'' – Bindee keelback *'' Rhabdophis callichroma'' – Bavi keelback *'' Rhabdophis callistus'' – Boettger's keelback *'' Rhabdophis ceylonensis'' – Sri Lanka blossom krait, Sri Lanka keelback *'' Rhabdophis chiwen'' – Chiwen keelback *'' Rhabdophis chrysargoides'' – Javanese keelback, Günther's keelback *'' Rhabdophis chrysargos'' – specklebelly keelback *'' Rhabdophis confusus'' *'' Rhabdophis conspicillatus'' – red-bellied keelback *'' Rhabdophis flaviceps'' – orangeneck keelback, orange-lipped keelback, yellow-headed keelback *'' Rhabdophis guangdongensis'' – Guangdong keelback *'' Rhabdophis helleri'' – Heller’s red-necked keelback *'' Rhabdophis himalayanus'' – orange-collared keelback *'' Rhabdophis hmongorum'' – H’mong keelback snake *'' Rhabdophis leonardi'' – Burmese keelback, Leonard's keelback *'' Rhabdophis lineatus'' – zigzag-lined water snake *'' Rhabdophis murudensis'' – Muruden keelback, Gunung Murud keelback *'' Rhabdophis nigrocinctus'' – black-striped keelback *'' Rhabdophis nuchalis'' – Hubei keelback *'' Rhabdophis pentasupralabialis'' *'' Rhabdophis plumbicolor'' – green keelback, lead keelback *'' Rhabdophis rhodomelas'' – blueneck keelback, blue-necked keelback *'' Rhabdophis siamensis'' *'' Rhabdophis subminiatus'' – red-necked keelback *'' Rhabdophis swinhonis'' – Swinhoe's grass snake *'' Rhabdophis tigrinus'' – tiger grooved-neck keelback, tiger keelback, Japanese grass snake, ''yamakagashi'' ''

Nota bene ( ; plural: ) is the Latin language, Latin phrase meaning ''note well''. In manuscripts, ''nota bene'' is abbreviated in upper-case as NB and N.B., and in lower-case as n.b. and nb; the editorial usages of ''nota bene'' and ''notate bene'' fi ...

'': A binomial authority in parentheses indicates that the species was originally described in a genus other than ''Rhabdophis''.

References

External links

Animal Diversity Web list of species of ''Rhabdophis''

Toxicity

Recent taxonomic changes

Species

References

External links

Further reading