rhabdophis

{{Automatic taxobox

| image = Rhabdop submin 080217-4693 ipb.jpg

| image_caption = Rhabdophis subminiatus

| taxon = Rhabdophis

| authority = Fitzinger, 1843

| subdivision_ranks = Species

| subdivision = 30, see text.

}}

Rhabdophis is a genus of snakes in the subfamily Natricinae of the family Colubridae. Species in the genus Rhabdophis are generally called keelback snakes, and are found primarily in Southeast Asia. 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.{{cite journal |last1=Mittleman |first1=M. |last2=Goris |first2=R. |title=Envenomation from the bite of the Japanese colubrid snake Rhabdophis tigrinus (Boie) |journal=Herpetologica |date=1974 |volume=30 |pages=113-119 |url=https://www.jstor.org/stable/3892025}}{{cite journal |last1=Smeets |first1=R. |last2=Melman |first2=P. |last3=Hoffmann |first3=J. |last4=Mulder |first4=A. |title=Severe coagulopathy after a bite from a ‘harmless’ snake (Rhabdophis subminiatus) |journal=Journal of Internal Medicine |date=1991 |volume=230 |pages=351-354 |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2796.1991.tb00455.x}}{{cite journal |last1=Hoffmann |first1=J. |last2=Vijgen |first2=M. |last3=Smeets |first3=R. |last4=Melman |first4=P. |title=Haemostatic effects in vivo after snakebite by the red-necked keelback (Rhabdophis subminiatus) |journal=Blood Coagulation & Fibrinolysis |date=1992 |volume=3 |pages=461-464 |url=https://journals.lww.com/bloodcoagulation/abstract/1992/08000/haemostatic_effectsin_vivoafter_snakebite_by_the.13.aspx}}{{cite journal |last1=Sawai |first1=Y. |last2=Honma |first2=M. |last3=Kawamura |first3=Y. |last4=Saki |first4=A. |last5=Hatsuse |first5=M. |title=Rhabdophis tigrinus in Japan: pathogenesis of envenomation and production of antivenom |journal=Toxin Reviews |date=2002 |volume=21 |pages=181-201 |url=https://www.tandfonline.com/doi/full/10.1081/TXR-120004746}} There are several reports of fatal bites from R. tigrinus.{{cite journal |last1=Mittleman |first1=M. |last2=Goris |first2=R. |title=Death caused by the bite of the Japanese colubrid snake Rhabdophis tigrinus (Boie)(Reptilia, Serpentes, Colubridae) |journal=Journal of Herpetology |date=1978 |volume=12 |pages=109-111 |url=https://www.jstor.org/stable/1563518}}{{cite journal |last1=Ogawa |first1=H. |last2=Sawai |first2=Y. |title=Fatal bite by yamakagashi (Rhabdophis tigrinus) |journal=The Snake |date=1986 |volume=18 |pages=53-54}} Between 1971 and 2020, 5 of 43 R. tigrinus bites in Japan were fatal,{{cite journal |last1=Hifumi |first1=T. |last2=Sakai |first2=A. |last3=Yamamoto |first3=A. |last4=Morokuma |first4=K. |last5=Otani |first5=N. |last6=Takahashi |first6=M. |last7=Ato |first7=M. |title=Rhabdophis tigrinus (yamakagashi) bites in Japan over the last 50 years: a retrospective survey |journal=Frontiers in Public Health |date=2022 |volume=9 |pages=775458 |url=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2021.775458/full}} all of which occurred in cases not treated with antivenom. Antivenom is manufactured by the Japan Snake Institute {{cite web |title=Anti-Yamakagashi Antivenom |url=https://www.antivenoms.toxinfo.med.tum.de/productinfo/ANTI-YAMAKAGASHI_ANTIVENOM.html |website=MAVIN Poison Center Munich |access-date=22 December 2024}} and is an effective treatment for R. tigrinus bites,{{cite journal |last1=Morokuma |first1=K. |last2=Kobori |first2=N. |last3=Fukuda |first3=T. |last4=Uchida |first4=T. |last5=Sakai |first5=A. |last6=Toriba |first6=M. |last7=Ohkuma |first7=K. |last8=Nakai |first8=K. |last9=Kurata |first9=T. |last10=Takahashi |first10=M. |title=Experimental manufacture of equine antivenom againt yamakagashi (Rhabdophis tigrinus) |journal=Japanese Journal of Infectious Diseases |date=2011 |volume=64 |issue=5 |pages=397-402 |url=https://www.jstage.jst.go.jp/article/yoken/64/5/64_64.397/_article/-char/ja/}}{{cite journal |last1=Hifumi |first1=T. |last2=Sakai |first2=A. |last3=Yamamoto |first3=A. |last4=Murakawa |first4=M. |last5=Ato |first5=M. |last6=Shibayama |first6=K. |last7=Kato |first7=H. |last8=Koido |first8=Y. |last9=Inoue |first9=J. |last10=Abe |first10=Y. |title=Effect of antivenom therapy of Rhabdophis tigrinus (yamakagashi snake) bites |journal=Journal of Intensive Care |date=2014 |volume=2 |issue=1 |pages=44 |url=https://link.springer.com/article/10.1186/s40560-014-0044-5}} but is an unapproved drug. The venom is highly hemorrhagic.{{cite journal |last1=Zotz |first1=R.B. |last2=Mebs |first2=D. |last3=Hirche |first3=H. |last4=Paar |first4=D. |title=Hemostatic changes due to the venom gland extract of the red-necked keelback snake (Rhabdophis subminiatus) |journal=Toxicon |date=1991 |volume=29 |pages=1501-1508 |url=https://www.sciencedirect.com/science/article/abs/pii/004101019190006D}}{{cite journal |last1=Chowdhury |first1=A. |last2=Lewin |first2=M.R. |last3=Carter |first3=R.W. |last4=Casewell |first4=N.R. |last5=Fry |first5=B.G. |title=Keel venom: Rhabdophis subminiatus (red-necked keelback) venom pathophysiologically affects diverse blood clotting pathways |journal=Toxicon |date=2022 |volume=218 |pages=19-24 |url=https://www.sciencedirect.com/science/article/pii/S0041010122002513}}

While the term "poisonous snake" is often incorrectly used for a wide variety of venomous snakes, 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 {{cite journal |last1=Mori |first1=A. |last2=Burghardt |first2=G.M. |last3=Savitzky |first3=A.H. |last4=Roberts |first4=K.A. |last5=Hutchinson |first5=D.A. |last6=Goris |first6=R.C. |title=Nuchal glands: a novel defensive system in snakes |journal=Chemoecology |date=2012 |volume=22 |pages=187-198 |url=https://link.springer.com/article/10.1007/s00049-011-0086-2}} that are used to store cardiotonic steroids (bufadienolides) sequestered from their diet,{{cite journal |last1=Hutchinson |first1=D. |last2=Mori |first2=A. |last3=Savitzky |first3=A.H. |last4=Burghardt |first4=G.M. |last5=Wu |first5=X. |last6=Meinwald |first6=J. |last7=Schroeder |first7=F.C. |title=Dietary sequestration of defensive steroids in nuchal glands of the Asian snake Rhabdophis tigrinus |journal=Proceedings of the National Academy of Sciences USA |date=2007 |volume=104 |pages=2265-2270 |url=https://www.pnas.org/doi/abs/10.1073/pnas.0610785104}} mostly from toads but also from firefly larvae.{{cite journal |last1=Yoshida |first1=T. |last2=Ujiie |first2=R. |last3=Savitzky |first3=A.H. |last4=Jono |first4=T. |last5=Inoue |first5=T. |last6=Yoshinaga |first6=N. |last7=Aburaya |first7=S. |last8=Aoki |first8=W. |last9=Takeuchi |first9=H. |last10=Ding |first10=L. |last11=Chen |first11=Q. |last12=Cao |first12=C. |last13=Tsai |first13=T.-S. |last14=de Silva |first14=A. |last15=Mahaulpatha |first15=D. |last16=Nguyen |first16=T.T. |last17=Tang |first17=Y. |last18=Mori |first18=N. |last19=Mori |first19=Anna |title=Dramatic dietary shift maintains sequestered toxins in chemically defended snakes |journal=Proceedings of the National Academy of Sciences USA |date=2020 |volume=117 |pages=5964-5969 |url=https://www.pnas.org/doi/abs/10.1073/pnas.1919065117}} Rhabdophis are resistant to the toxic effects of these chemicals.{{cite journal |last1=Mohammadi |first1=S. |last2=Gompert |first2=Z. |last3=Gonzalez |first3=J. |last4=Takeuchi |first4=H. |last5=Mori |first5=A. |last6=Savitzky |first6=A.H. |title=Toxin-resistant isoforms of Na+/K+-ATPase in snakes do not closely track dietary specialization on toads |journal=Proceedings of the Royal Society B: Biological Sciences |date=2016 |volume=283 |pages=20162111 |url=https://royalsocietypublishing.org/doi/full/10.1098/rspb.2016.2111}} 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.{{cite journal |last1=Hutchinson |first1=D.A. |last2=Savitzky |first2=A.H. |last3=Mori |first3=A. |last4=Meinwald |first4=J. |last5=Schroeder |first5=F.C. |title=Maternal provisioning of sequestered defensive steroids by the Asian snake Rhabdophis tigrinus |journal=Chemoecology |date=2008 |volume=18 |pages=181-190 |url=https://link.springer.com/article/10.1007/s00049-008-0404-5}}

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.{{cite journal |last1=Takeuchi |first1=H. |last2=Savitzky |first2=A.H. |last3=Ding |first3=L. |last4=de Silva |first4=A. |last5=Das |first5=I. |last6=Nguyen |first6=T.T. |last7=Tsai |first7=T.-S. |last8=Jono |first8=T. |last9=Zhu |first9=G.-X. |last10=Mahaulpatha |first10=D. |last11=Tang |first11=Y. |last12=Mori |first12=A. |title=Evolution of nuchal glands, unusual defensive organs of Asian natricine snakes (Serpentes: Colubridae), inferred from a molecular phylogeny |journal=Ecology & Evolution |date=2018 |volume=8 |pages=10219-10232 |url=https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.4497}} 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 are recognized as being valid:{{EMBL genus|genus=Rhabdophis}}. www.reptile-database.org.

Rhabdophis adleri {{small|Zhao, 1997}}
Rhabdophis akraios {{small|Doria, Petri, Bellati, Tiso & Pistarino, 2013}} – Singalang keelback
Rhabdophis angeli {{small|(Bourret, 1934)}} – Angel's keelback
Rhabdophis auriculatus {{small|(Günther, 1858)}} – white-lined water snake
Rhabdophis barbouri {{small|(Taylor, 1922)}} – Barbour's water snakeBeolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. {{ISBN|978-1-4214-0135-5}}. (Rhabdophis barbouri, p. 16; R. swinhonis, p. 258).
Rhabdophis bindi {{small|Das, E.N. Smith, Sidik, Sarker, Boruah, N.G. Patel, Murthy & Deepak, 2021}} – Bindee keelback
Rhabdophis callichroma {{small|(Bourret, 1934)}} – Bavi keelback
Rhabdophis callistus {{small|(Günther, 1873)}} – Boettger's keelback
Rhabdophis ceylonensis {{small|(Günther, 1858)}} – Sri Lanka blossom krait, Sri Lanka keelback
Rhabdophis chiwen {{small|Z. Chen, Ding, Q. Chen & Piao, 2020}} – Chiwen keelback
Rhabdophis chrysargoides {{small|(Günther, 1858)}} – Javanese keelback, Günther's keelback
Rhabdophis chrysargos {{small|(Schlegel, 1837)}} – specklebelly keelback
Rhabdophis confusus {{small|David & G. Vogel, 2021}}
Rhabdophis conspicillatus {{small|(Günther, 1872)}} – red-bellied keelback
Rhabdophis flaviceps {{small|(A.M.C. Duméril, Bibron & A.H.A. Duméril, 1854)}} – orangeneck keelback, orange-lipped keelback, yellow-headed keelback
Rhabdophis guangdongensis {{small|Zhu, Wang, Takeuchi & Zhao, 2014}} – Guangdong keelback
Rhabdophis helleri {{small|(Schmidt, 1925)}} – Heller’s red-necked keelback
Rhabdophis himalayanus {{small|(Günther, 1864)}} – orange-collared keelback
Rhabdophis hmongorum {{small|(Kane, Tapley, La & Nguyen, 2023)}} – H’mong keelback snake
Rhabdophis leonardi {{small|(Wall, 1923)}} – Burmese keelback, Leonard's keelback
Rhabdophis lineatus {{small|(W. Peters, 1861)}} – zigzag-lined water snake
Rhabdophis murudensis {{small|(M.A. Smith, 1925)}} – Muruden keelback, Gunung Murud keelback
Rhabdophis nigrocinctus {{small|(Blyth, 1856)}} – black-striped keelback
Rhabdophis nuchalis {{small|(Boulenger, 1891)}} – Hubei keelback
Rhabdophis pentasupralabialis {{small|Jiang & Zhao, 1983}}
Rhabdophis plumbicolor {{small|(Cantor, 1839)}} – green keelback, lead keelback
Rhabdophis rhodomelas {{small|(H. Boie, 1827)}} – blueneck keelback, blue-necked keelback
Rhabdophis siamensis {{small|(Mell, 1931)}}
Rhabdophis subminiatus {{small|(Schlegel, 1837)}} – red-necked keelback
Rhabdophis swinhonis {{small|(Günther, 1868)}} – Swinhoe's grass snake
Rhabdophis tigrinus {{small|(H. Boie, 1826)}} – tiger grooved-neck keelback, tiger keelback, Japanese grass snake, yamakagashi

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

References

External links

[http://animaldiversity.ummz.umich.edu/site/accounts/classification/Rhabdophis.html Animal Diversity Web list of species of Rhabdophis]
[https://web.archive.org/web/20050425013545/http://www.omne-vivum.com/c/38882.htm Omne vivum list of species]