{{Short description|Species of snake}} {{Speciesbox | image = | image_caption = | status = VU | status_system = IUCN3.1 | status_ref = <ref name="Halim-2024" /> | genus = Trimeresurus | species = nebularis | authority = Vogel, David and [[Olivier Sylvain Gérard Pauwels|Pauwels]], 2004 }} [[File:Trimeresurus_nebularis_au_parc_de_Bako_(Malaisie).jpg|thumb| ]] [[File:Cameron_Highlands_Pit_Viper_(Trimeresurus_nebularis)_(Photo_by_Xavier_MALLERET)_(24622319436).jpg|thumb| ]]
'''''Trimeresurus nebularis''''' (also known as the '''Cameron Highlands pit viper''' or the '''clouded pit viper''') is a species of [[pit viper]] found in the [[Cameron Highlands District]] of west [[Malaysia]] and [[Thailand]].<ref name="Vogel-2004">{{Cite journal|last1=Vogel|first1=Gernot|last2=David|first2=Patrick|last3=Pauwels|first3=Olivier S. G.|date=2004-11-15|title=A review of morphological variation in Trimeresurus popeiorum (Serpentes: Viperidae: Crotalinae), with the description of two new species|url=https://www.biotaxa.org/Zootaxa/article/view/zootaxa.727.1.1|journal=Zootaxa|language=en|volume=727|issue=1|pages=1–63|doi=10.11646/zootaxa.727.1.1|issn=1175-5334|url-access=subscription}}</ref>
== Taxonomy == ''Trimeresurus nebularis'' was described in 2004. Previously, ''Trimeresurus'' from this area were considered part of ''[[Craspedocephalus gramineus|Trimeresurus gramineus]]'' or ''[[Trimeresurus popeiorum]]''.<ref name="The Reptile Database" /> ''Trimeresurus nebularis'' is part of the subgenus ''Popeia''.<ref>{{Cite journal |last1=Mirza |first1=Zeeshan A. |last2=Lalremsanga |first2=H. T. |last3=Bhosale |first3=Harshal |last4=Gowande |first4=Gaurang |last5=Patel |first5=Harshil |last6=Idiatullina |first6=Sabira S. |last7=Poyarkov |first7=Nikolay A. |date=2023 |title=Systematics of <i>Trimeresurus popeiorum</i> Smith, 1937 with a revised molecular phylogeny of Asian pitvipers of the genus <i>Trimeresurus</i> Lacépède, 1804 sensu lato |url=https://evolsyst.pensoft.net/article/97026/ |journal=Evolutionary Systematics |volume=7 |issue=1 |pages=91–104 |doi=10.3897/evolsyst.7.97026 |doi-access=free |issn=2535-0730}}</ref>
=== Etymology === The name ''Trimeresurus nebularis'' comes from the Latin word nebularis which means "from the clouds". This refers to the [[Cloud forest|cloud forests]] that the species inhabits.<ref name="The Reptile Database">{{Cite web |title=Trimeresurus nebularis |url=https://reptile-database.reptarium.cz/species?genus=Trimeresurus&species=nebularis&search_param=((search='Trimeresurus+nebularis')) |access-date=2025-04-15 |website=The Reptile Database}}</ref>
== Description == Males can be around {{Convert|100|cm|in|abbr=on}} in length and females can reach around {{Convert|95|cm|in|abbr=on}} in total length.<ref name="The Reptile Database" /><ref name="Halim-2024">{{Cite news |last=Nur Hazwanie Binti Abd Halim, Nurfarhana Hizan Binti Hijas, Ahmad Khaldun Ismail, Indraneil Das & Kaviarasu Munian |title=Trimeresurus nebularis Vogel, David & Pauwels, 2004 |url=https://www.mybis.gov.my/art/399 |archive-url=https://web.archive.org/web/20240418225449/https://www.mybis.gov.my/art/399 |archive-date=2024-04-18 |access-date=2025-03-24 |work=Malaysia Biodiversity Information System (MyBIS) |language=en |url-status=live }}</ref><ref>{{Cite journal |last=Smedley |first=N. |date=1931 |title=Amphibians and reptiles from the Cameron Highlands, Malay Peninsula |url=https://lkcnhm.nus.edu.sg/wp-content/uploads/sites/11/app/uploads/2017/06/06brm105-123.pdf |journal=Bulletin of the Raffles Museum |volume=6 |pages=105–123}}</ref> The body of ''T. nebularis'' is cylindrical and bright green. Males have a white or blue ventro-lateral stripe.<ref name="Vogel-2004" /> The [[Pupil|pupils]] are vertical and usually have a yellowish-green [[Iris (anatomy)|iris]].<ref name="Vogel-2004" /> Both males and females usually have blue upper lips.<ref name="The Reptile Database" /> The scales around the throat/chin area are yellowish green while the upper scales are greenish-blue.<ref name="Halim-2024" /> The tail is a brown rust color on its vertebral region and has a distinct line in between. The rust color and the green [[Anatomical terms of location|lateral]] color makes it distinguishable from other pit vipers.<ref name="Halim-2024" />
== Reproduction == Like other ''Trimeresurus'', this species is [[Ovoviviparity|ovoviviparous]]. Males have long hemipenes with no spines.<ref name="The Reptile Database" />
== Distribution and habitat == ''T. nebularis'' is restricted to high elevations above {{Convert|1000|m|ft|abbr=on}}.<ref name="Halim-2024" /> ''T. nebularis'' resides in both [[Thailand]] and [[Malaysia]] in the central part of the [[Titiwangsa Mountains|Titiwangsa Range]] in the [[Cameron Highlands]]. It has also been seen in [[Fraser's Hill|Fraser’s Hill]] along with the [[Genting Highlands]] in the [[Pahang|Pahang State]] in Malaysia.<ref name="Tan-2019">{{Cite journal |last1=Tan |first1=Choo Hock |last2=Tan |first2=Kae Yi |last3=Shan Ng |first3=Tzu |last4=Quah |first4=Evan S.H. |last5=Khaldun Ismail |first5=Ahmad |last6=Khomvilai |first6=Sumana |last7=Sitprija |first7=Visith |last8=Hong Tan |first8=Nget |date=6 February 2019 |title=Venomics of Trimeresurus (Popeia) nebularis, the Cameron Highlands Pit Viper from Malaysia: Insights into Venom Proteome, Toxicity and Neutralization of Antivenom |journal= Toxins|volume=11 |issue=2 |page=95 |doi=10.3390/toxins11020095 |pmid=30736335 |doi-access=free |pmc=6410072 }}</ref>
== Venom == The venom of ''T. nebularis'' under [[SDS-PAGE|sodium dodecyl sulfate-polyacrylamide gel electrophoresis]] showed a complex mixture that consisted of a wide range of [[Protein|proteins]].<ref name="Tan-2019" /> Some of the proteins include [[metalloproteinase]], [[C-type lectin]]/lectin-like proteins and [[serine protease|serine proteases]].<ref name="Tan-2019" /> A total of 44 proteins were identified in the venom, forty of those proteins were grouped into 9 different families of [[Toxin|toxins]]. The venom can potentially cause [[coagulopathy]] if they bite a human, impairing the coagulation process of blood and causing bleeding.<ref name="Halim-2024" /> Although epidemiological data are absent, ''T. nebularis'' is one of the leading causes of snakebite envenomation within its range.<ref>{{Cite book |last=Ismail |first=A.K. |title=Clinical Toxinology in Asia Pacific and Africa |date=2015 |publisher=Springer |location=Dordrecht |pages=71–102 |chapter=Snakebite and Envenomation Management in Malaysia}}</ref>
== Vulnerability == This species is listed as vulnerable by the IUCN. If threats against the animal continue, it may progress to a more severe rating on the list.<ref name="Halim-2024" />
== References == {{Reflist}}
{{Taxonbar|from=Q5094604}}
[[Category:Trimeresurus|nebularis]] [[Category:Taxa named by Olivier Sylvain Gérard Pauwels]]
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