View source for Northern green anaconda

{{Short description|Disputed species of snake}}
{{good article}}
{{Use dmy dates|date=February 2024}}
{{Merge to |Green anaconda|date=August 2024|discuss=Talk:Northern_green_anaconda#Latest_paper_just_out,_synonymizing_akayima_with_murinus_-_next_steps?}}
{{Speciesbox
| name = Northern green anaconda
| image = Anaconda (Eunectes akayima).jpg
| image_caption = ''Eunectes akayima'' in the [[Venezuelan Llanos]]
| genus = Eunectes
| species = akayima
| authority = Rivas ''et al.'', 2024
}}

The '''northern green anaconda''' ('''''Eunectes akayima''''') is a disputed [[Boidae|boa]] species found in northern [[South America]] and the [[Caribbean]] island of [[Trinidad]]. It is closely related to ''[[Eunectes murinus]]'', the (southern) green anaconda, from which it was claimed to be genetically distinct in 2024. It is one of the [[List of largest snakes|heaviest and longest]] snakes in the world, with one specimen reported by a newspaper to have been {{convert|6.3|m}} long. Like all boas, it is a [[venom|non-venomous]] [[Constriction|constrictor]].
''E. akayima'' is estimated to have diverged from its closest relative between 5 and 20 million years ago, originally separated by the [[Vaupés Arch]]. Today, specimens of ''E. akayima'' are known from the [[Orinoco basin]] and surrounding regions, ranging from [[Ecuador]] to [[Trinidad]]. Its range is still mostly separate from that of ''E. murinus'', although they partially overlap around [[French Guiana]], with no clear geographical barrier. While allegedly separated through [[mitochondrial DNA]] markers, the two species are indistinguishable in morphology.

The anacondas in the region have been known for centuries as ''akayima'' by the local [[Kalina people|Carib people]], and this became the formal scientific name proposed for the species. Later studies raised [[International Code of Zoological Nomenclature|nomenclatural]] issues about the description, while also calling into question the validity of the clades recovered through mitochondrial DNA, casting doubt on the validity of ''E. akayima'' as a separate species.

== History ==

=== Previous proposals ===
Before the discovery of ''E. akayima'', several proposals were made to split a new species or [[subspecies]] from the [[green anaconda]] (''Eunectes murinus''), such as ''Eunectes gigas'' (Latreille, 1801), or ''Eunectes barbouri'' (Dunn and Conant, 1936).<ref name=SAL98>{{Cite journal |last1=Dirksen |first1=Lutz |last2=Böhme |first2=Wolfgang |date=31 December 1998 |title=Studien an Anakondas 2: Zum taxonomischen Status von Eunectes murinus gigas (LATREILLE, 1801) (Serpentes: Boidae), mit neuen Ergebnissen zur Gattung Eunectes W AGLER, 1830 |url=http://www.salamandra-journal.com/index.php/home/contents/1998-vol-34/622-dirksen-l-w-boehme/file |journal=Salamandra |volume=34 |issue=4 |pages=1–16|archive-url=https://web.archive.org/web/20190805143936/http://www.salamandra-journal.com/index.php/home/contents/1998-vol-34/622-dirksen-l-w-boehme/file |archive-date=5 August 2019 }}</ref><ref name=JOH>{{Cite journal |last1=Strimple |first1=Peter D. |last2=Puorto |first2=Giuseppe |last3=Holmstrom |first3=William F. |last4=Henderson |first4=Robert W. |last5=Conant |first5=Roger |date=December 1997 |title=On the Status of the Anaconda Eunectes barbouri Dunn and Conant |url=https://www.jstor.org/stable/1565623 |journal=[[Journal of Herpetology]] |volume=31 |issue=4 |pages=607 |doi=10.2307/1565623 |jstor=1565623 |access-date=1 March 2024 |archive-date=26 March 2020 |archive-url=https://web.archive.org/web/20200326022720/https://www.jstor.org/stable/1565623 |url-status=live |url-access=limited }}</ref><ref name=AR>{{Cite journal |last1=Tarkhnishvili |first1=David |last2=Hille |first2=Axel |last3=Waller |first3=Thomas |last4=Todua |first4=Mariam |last5=Murtskhvaladze |first5=Marine |last6=Böhme |first6=Wolfgang |date=2 November 2022 |title=Morphological trends and genetic divergence in anacondas, genus ''Eunectes'' Wagler, 1830 (Serpentes: Boidae) |url=https://brill.com/view/journals/amre/43/4/article-p379_6.xml |journal=Amphibia-Reptilia |volume=43 |issue=4 |pages=379–393 |doi=10.1163/15685381-bja10114 |issn=1568-5381 |access-date=1 March 2024 |archive-date=21 February 2024 |archive-url=https://web.archive.org/web/20240221214305/https://brill.com/view/journals/amre/43/4/article-p379_6.xml |url-status=live |url-access=subscription}}</ref>

''Boa gigas'', later ''Eunectes gigas'' or ''Eunectes murinus gigas'', was proposed in 1801, at first described from specimens in [[Guyana]] and [[Trinidad]] but later believed to range from [[Colombia]] to [[French Guiana]]. It was distinguished by a lighter [[Ocular scales|postocular]] coloration, as well as differences in [[Snake scale#Taxonomic importance|scale count]] in the [[Ventral scales|ventral]] and [[Subcaudal scales|subcaudal]] regions. The coloration was later found to be uniformly distributed throughout the green anaconda's range, while the scale count was found not to differ significantly between the putative subspecies. This showed ''E. m. gigas'' to be a color variation rather than a true subspecies.<ref name=SAL98/>

''Eunectes barbouri'' was described in 1936 from an individual donated to [[Philadelphia Zoo]], believed to originate from the island of [[Marajó]] in northern Brazil. The [[holotype]] was distinguished from ''E. murinus'' specimens by the coloration pattern of its dorsal spots. In the presumed ''E. barbouri'' holotype, the latter had a dark border with a light center, while they were uniformly dark in ''E. murinus''. Beyond the holotype, ''E. barbouri'' was estimated to have a wider range throughout Brazil, with another attributed specimen originating from [[Barreiras]].<ref name=JOH/>

The validity of ''E. barbouri'' was debated by some contemporary authors, although others continued to maintain the distinctness of the species.<ref name=JOH/> A 1970 expedition on Marajó failed to find any ''E. barbouri'' specimens, with the only individuals encountered being ''E. murinus''.<ref name=SAL70>{{Cite journal |last=Müller |first=P. |date=1970 |title=Über die Eunectes-Arten von Marajo |url=http://archive.org/details/salamandra-6-140-141 |language=German |journal=Salamandra |pages=140–141 |volume=6 |issue=3/4}}</ref> Later studies have cast doubts on the diagnostic characteristics used to define the species, with the spot patterns being found to be part of the natural color variation in ''E. murinus'',<ref name=SAL98/><ref name=JOH/> while a 2022 genetic study upheld the synonymy of the two species.<ref name=AR/>

=== Discovery ===
In 2024, research claimed through genetic testing that populations of ''Eunectes murinus'' found in northern South America formed a [[clade]] distinct from those occurring farther south.&nbsp;The approximately 5.5 percent difference in&nbsp;[[mitochondrial DNA]]&nbsp;prompted the northern populations to be described as a separate species, ''Eunectes akayima'', by the researchers.&nbsp;Both wild and captive specimens were tested with blood samples taken. While nuclear DNA failed to show measurable differences between the two species, authors attributed this to the lack of appropriate markers with high enough variation rates, with nuclear genomic studies barely separating ''E. murinus'' from the more distant ''[[Eunectes notaeus|E. notaeus]]''.<ref name="NG"/><ref name="D"/>

Samples were taken in multiple locations throughout South America over the course of 20 years in a study led by [[New Mexico Highlands University]] professor Jesús Rivas, measuring both genetic data through blood and tissue samples and anatomical characteristics like scale count, as well as habitat data. An earlier specimen, MCNG 1042, was designated as the holotype. This specimen, collected by Jesús Rivas in 1993 at Hato El Cedral in the [[Venezuelan Llanos]], is now preserved by the {{ill|UNELLEZ|es}} in the Museo de Ciencias Naturales de Guanare.<ref name="D"/><ref name="TC"/>

Several of the specimens were found in a 2022 expedition by researchers working with indigenous [[Huaorani people]], who consider the anaconda sacred, in the [[Geography of Ecuador#El Oriente (the East) Amazon Basin|Ecuadorian Amazon]]. The 10-day expedition, organized with Huaorani leader Penti Baihua, was accompanied by the filming of the ''Pole to Pole with Will Smith'' series for [[National Geographic]], with actor [[Will Smith]] taking part in the expedition. The Huaorani collaborators were acknowledged as co-authors in the discovery paper.<ref name="TC"/><ref name="TI"/><ref name="UQ"/>

=== Reactions ===
The description of ''Eunectes akayima'' has been favorably received by {{ill|Wolfgang Böhme (zoologist){{!}}Wolfgang Böhme|de|Wolfgang Böhme (Zoologe)}}, who acknowledged the validity of the genetic divide between the two green anaconda species. However, the study's other result of merging the yellow anaconda species ''[[Eunectes deschauenseei]]'' and ''[[Eunectes beniensis|E. beniensis]]'' into ''[[Eunectes notaeus|E. notaeus]]'' was criticized as premature by Böhme, whose own study upheld ''E. beniensis'' as distinct two years earlier.<ref name="NG"/><ref name=AR/>

Two reviews published in the month following the discovery criticized the original publication. The first critique, by Vásquez-Restrepo ''et al.'', only discussed the validity of the name ''Eunectes akayima'' on procedural grounds, pointing out violations of the [[International Code of Zoological Nomenclature]]. While also raising nomenclatural criticism, the second study by Dubois ''et al.'' additionally cast doubt on the reliability of the genetic markers used, and on the existence of a separate northern green anaconda species.<ref name=B1>{{Cite journal |last1=Vásquez-Restrepo |first1=Juan D. |last2=Alfonso-Rojas |first2=Andrés |last3=Palacios-Aguilar |first3=Ricardo |date=2024-03-15 |title=On the validity of the recently described northern green anaconda Eunectes akayima (Squamata, Serpentes) |url=https://mapress.com/bn/article/view/bionomina.37.1.1 |journal=Bionomina |language=en |volume=37 |pages=1–7 |doi=10.11646/bionomina.37.1.1 |issn=1179-7657 |url-access=subscription}}</ref><ref name=B2>{{Cite journal |last1=Dubois |first1=Alain |last2=Denzer |first2=Wolfgang |last3=Entiauspe-Neto |first3=Omar M. |last4=Frétey |first4=Thierry |last5=Ohler |first5=Annemarie |last6=Bauer |first6=Aaron M. |last7=Pyron |first7=Alexander |date=2024-03-15 |title=Nomenclatural problems raised by the recent description of a new anaconda species (Squamata, Serpentes, Boidae), with a nomenclatural review of the genus Eunectes |url=https://mapress.com/bn/article/view/bionomina.37.1.2 |journal=Bionomina |language=en |volume=37 |pages=8–58 |doi=10.11646/bionomina.37.1.2 |issn=1179-7657 |url-access=subscription}}</ref> <!-- This is an overview of the studies published, the specific results and arguments are to be added in relevant sections -->

=== Future studies ===
Follow-up studies of ''E. akayima'' have been considered by the discovering team, aiming to understand the green anaconda's evolutionary history and the split between the two species. The differences in genital configurations of the two species is also an open topic of research. These often vary even among related species of snakes, as non-compatible genitals are often a factor preventing interbreeding between nearby populations and leading to further divergence between species.<ref name="NG"/>

== Nomenclature ==
=== Type specimen ===
[[File:Linnaeus Boa murina.png|thumb|Original description of the ''Boa murina'' syntype studied by [[Carl Linnaeus|Linnaeus]]<ref>{{Cite book |last=Linné |first=Carl von |author-link=Carl Linnaeus |url=https://www.biodiversitylibrary.org/item/209402 |title=Museum Adolphi Friderici Reginae Suecorum  |date=1764 |publisher=Laur. Salvius |location=Stockholm |pages=42 |language=la |access-date=2024-03-18}}</ref> (specimen #319, identified as NRM9 in the Adolphi Friderici Museum collection)<ref name="D"/>]]
While [[Carl Linnaeus]] originally described ''Boa murina'' in 1758, the precise location of the species' [[syntype]]s is not known, with the most likely locations of Suriname and French Guiana being contact zones between both populations. As the required genetic testing is not possible on samples of that age, it is uncertain which species the type specimens belonged to, making the choice of which species to refer to as ''Eunectes murinus'' ultimately arbitrary. With the southern clade being the most widespread, discoverers opted to keep the original name for the latter in the name of taxonomic stability. They designated as [[lectotype]] for ''E. murinus'' a specimen found in the [[Xingu River]] of [[Pará]], Brazil in 2011 and now hosted in the [[Museu Paraense Emílio Goeldi]], and established the northern population as a new species, ''Eunectes akayima''.<ref name="D"/>

=== Etymology ===
The species' name&nbsp;''akayima''&nbsp;comes from the local [[Cariban languages]], with ''akayi'' meaning "snake" and the suffix ''-ima'' describing largeness in a way that elevates the term to a separate category, giving a literal meaning of "The Great Snake". The word ''akayima'' and variants (''okoyimo'', ''okoimo'') have been used by the local [[Kalina people|Carib people]] to refer to the northern green anaconda for centuries before its formal scientific description. The term also refers in Cariban languages to the rainbow, likely associated with a feathered serpent in Carib beliefs.<ref name="D"/> The [[Pemon|Arekuna]], for instance, speak of a rainbow serpent in their creation narrative, believed to be the source of all birds' plumage.<ref>{{Cite journal |last=Liebenberg |first=Deon |date=2016 |title=The Rainbow-Snake and the Birds' Plumage: An Exploration of the Theme of the Continuous and the Discrete in Claude Lévi-Strauss's Mythologiques |url=https://www.jstor.org/stable/10.2979/jfolkrese.53.3.03 |journal=[[Journal of Folklore Research]] |volume=53 |issue=3 |pages=167–203 |doi=10.2979/jfolkrese.53.3.03 |jstor=10.2979/jfolkrese.53.3.03 |issn=0737-7037}}</ref> Among the Carib peoples, the [[Wai-wai people|Wai-wai]] also give mythological significance to the ''Okoimo-Yenna'' or "anaconda people", understood either as relatives<ref name=JASO>{{Cite journal |last=Morton |first=John |date=January 1976 |title='Dan Sperber and the anacondas': an ethnographic comment on Sperber's theory of symbolism |url=https://paperity.org/p/229044005/dan-sperber-and-the-anacondas-an-ethnographic-comment-on-sperbers-theory-of-symbolism |journal=[[Journal of the Anthropological Society of Oxford]] |volume=3 |pages=109–120 |via=Paperity}}</ref> or as opposite counterparts to human beings.<ref name=JSTOR>{{Cite journal |last=Oakley |first=R. Elliott |date=2019 |title='Opening Up' the Village: Canoes, Conservation and Contending with Transformation in Amazonia |url=https://www.jstor.org/stable/26856484 |journal=Etnofoor |volume=31 |issue=2 |pages=33–50 |jstor=26856484 |issn=0921-5158}}</ref>

The continued use of the name by indigenous people prior to the advent of the [[ICZN]], along with the invalidity of previous proposed splits of ''E. murinus'' due to inconsistencies in differentiation, prompted the researchers to accept ''akayima'' as the senior synonym for the species.<ref name="D"/>

=== Nomenclatural availability and validity ===
A review by Vásquez-Restrepo ''et al.'' argued against the [[Valid name (zoology)|validity]] of ''E. akayima'', pointing out several purported violations of the ICZN in the Rivas ''et al.'' article. Notably, they concluded that the oldest available name for this taxon was ''Eunectes gigas'' (Latreille, 1801), historically considered the northern subspecies of ''E. murinus'', but for which no evidence of distinctiveness had been provided prior to Rivas ''et al.''{{'}}s molecular analyses.<ref name="B1"/>

Separately, Dubois ''et al.'' criticized the publication for lacking a well-defined [[species concept]], while questioning the validity of the clades recovered through mitochondrial DNA. Their review claimed that the name itself was not validly published under the rules of the [[ICZN|Zoological Code (ICZN)]] as it violated Article 13 of the Code,{{efn|The relevant section of Article 13 requires "a description or definition that states in words characters that are purported to differentiate the taxon"<ref name=ICZN>{{Cite web |title=Article 13. Names published after 1930 {{!}} International Code of Zoological Nomenclature |url=https://code.iczn.org/chapter-4-criteria-of-availability/article-13-names-published-after-1930/ |access-date=2024-03-17 |website=code.iczn.org}}</ref>}} and labeled the designation as a ''[[nomen nudum]]''. This would make the proposed name [[Unavailable name|unavailable]], rather than only invalid as Vásquez-Restrepo ''et al.'' concluded.<ref name="B2"/>

Both studies also considered the designation of the ''Eunectes murinus'' lectotype by Rivas ''et al.'' to be invalid, with Dubois ''et al.'' pointing out that the specimen (only collected in 2011) was not part of the syntypes designated by Linnaeus, and thus not valid as a lectotype. The latter study instead designated as lectotype a specimen collected by [[Albertus Seba]] in the [[Spanish West Indies]], referenced by Linnaeus in his original description.<ref name="B1"/><ref name="B2"/>

== Genetic history ==
[[File:Eunectes akayima cladogram.png|thumb|300px|Cladogram of ''Eunectes akayima'' and related species, with estimates of its divergence with ''E. murinus'' according to different scenarios]]
The [[Speciation|divergence]] between ''Eunectes akayima'' and ''E. murinus'' has been estimated to have occurred between 5 and 20 million years ago, during the [[Miocene]]. Molecular clock analyses were calibrated using the earlier split between the geographically isolated [[Sanziniinae]] (found in Madagascar) and the rest of [[Boidae]], along with fossil evidence. Approaches vary depending on the scenario considered for the aforementioned split, with scenarios involving one [[land bridge]], two, or none providing different hard minimums for the Boidae divergence, and thus different calibrations for the split between the two species. Another method, only considering fossil evidence, led to the most recent estimate for the split between ''E. akayima'' and ''E. murinus'', placing it between 5 and 11 million years ago.<ref name="D"/>

The split between the two green anaconda species has been claimed by the discovering team to parallel other such north-south splits in South American fauna, such as between the [[northern caiman lizard]] (''Dracaena guianensis'') and the [[Paraguay caiman lizard]] (''Dracaena paraguayensis''), or between the [[Orinoco mata mata]] (''Chelus orinocensis'') and the [[Amazon mata mata]] (''Chelus fimbriata''). This was attributed by the authors to the rise of the [[Vaupés Arch]] between the [[Andes]] and the [[Guyana Shield]], which created a [[Habitat fragmentation|geographical barrier]] between populations in the [[Orinoco basin|Proto-Orinoco]] and [[Amazon basin|Proto-Amazon river basins]]. Modern ''E. akayima'' populations can be found farther south than the Vaupés Arch, and there is currently no geographical barrier between the two species.<ref name="D"/><ref name="TC"/>

A more recent divergence inside ''E. akayima'' has been dated to {{circa|3 [[Megaannum|Ma]]}}, splitting populations in Venezuela south of the [[Orinoco Delta]]. This is believed to coincide with the beginning of the [[Quaternary glaciation]], as the sequestration of water by the ice caps led to wetlands receding, while forests grew and separated the Orinoco and Amazon river basins once again.<ref name="D"/>

== Description ==
''Eunectes akayima'' has been described as one of the world's [[List of largest snakes|heaviest and longest snakes]], with one specimen described in a newspaper article quote as being {{convert|6.3|m}} long.<ref name="TI"/> Unconfirmed reports from native [[Huaorani people]] speak of individuals reaching {{convert|7.5|m}} and {{convert|500|kg}}.<ref name="NG"/><ref name="TI">{{Cite news |last=Sankaran |first=Vishwam |date=23 February 2024 |title=Biggest snake species in the world discovered in Amazon rainforest |url=https://www.independent.co.uk/news/science/biggest-anaconda-ever-found-26ft-northern-green-b2501077.html |access-date=28 February 2024 |language=en |website=[[The Independent]] |archive-date=28 February 2024 |archive-url=https://web.archive.org/web/20240228221241/https://www.independent.co.uk/news/science/biggest-anaconda-ever-found-26ft-northern-green-b2501077.html |url-status=live }}</ref>

While the two are allegedly<ref name="B2"/> distinguished by their [[Mitochondrial DNA|mitochondrial genomes]], no morphological differences have yet been recognized between ''E. akayima'' and ''E. murinus'', making them [[cryptic species]]. Morphological measurements such as [[Snake scale#Taxonomic importance|scale count]] in several locations have been found to lie in the same ranges in both species.<ref name="D"/>

== Ecology and behavior ==
Northern green anacondas are [[ambush predator]]s, and are among the [[apex predator]]s in the swamps, rivers and other wetlands of northern South America, spending most of their time submerged in shallow waters. They hunt by waiting for prey to come nearby, with the buoyancy of the water helping them to rapidly leap out and take hold of the prey with their strong jaws. Like other [[boid]]s, they are non-venomous [[Constriction|constrictors]], subduing their prey by wrapping themselves around and asphyxiating it, often crushing the prey before swallowing it whole.<ref name=TI/><ref name=TC/>

Prey of the northern green anaconda include large animals such as [[capybara]]s, [[caiman]]s and [[deer]]. It is a [[keystone species]] in its ecosystem, whose presence impacts the habits and migration patterns of other species in the surrounding environment. Despite popular beliefs, there have been no confirmed records of ''E. akayima'' hunting or eating humans.<ref name=TC/><ref name=NG/>

== Distribution and habitat ==
[[File:Green anaconda range map.png|thumb|300px|Range of sampled ''Eunectes akayima'' (in light green) and ''Eunectes murinus'' (in dark green) individuals]]
''Eunectes akayima''&nbsp;is found in northern [[South America]]. The precise distribution area is not yet known, but based on samples taken, the species is known to occur in [[Venezuela]], [[French Guiana]], [[Suriname]], [[Guyana]], [[Ecuador]], and the island of [[Trinidad]]. Its range is also believed to include parts of [[Colombia]] and [[Peru]], as well as [[northern Brazil]].<ref name="D"/>

Contact regions have been discovered, such as French Guiana and likely Suriname, where populations of both green anaconda species overlap with each other.<ref name="D"/> While specimens of both have been found in nearby localities, notably on opposite riverbanks from each other, the two species have not been found to [[Hybrid (biology)|interbreed]].<ref name=NG/>

== Conservation ==
The possibility of ''E. akayima'' being a separate species reveals a higher conservation risk than previously believed, despite the green anaconda being originally assessed as [[Least Concern]] by the [[IUCN]] due to its broad range. Lack of precise knowledge about population distribution make the assessment of both species' true status difficult, while the different ecological habitats and threats faced by both species mean specific conservation programs must be established for each of them.<ref name="D"/><ref name="TC"/><ref name="IUCN">{{cite IUCN|title=''Eunectes murinus''|page=e.T44580041A44580052|date=2021|last1=Calderón|first1=M.|last2=Ortega|first2=A.|last3=Scott|first3=N.|last4=Cacciali|first4=P.|last5=Nogueira|first5=C. de C.|last6=Gagliardi|first6=G.|last7=Catenazzi|first7=A.|last8=Cisneros-Heredia|first8=D.F.|last9=Hoogmoed|first9=M.S.|last10=Schargel|first10=W.|last11=Rivas|first11=G.|last12=Murphy|first12=J.|access-date=28 February 2024}}</ref> Notably, the northern green anaconda's smaller range makes it much more vulnerable than its southern neighbor.<ref name=NG/>

As with other anaconda species, main threats include conflict with humans, as well as [[Habitat destruction|habitat degradation and fragmentation]] caused by agriculture, climate change and oil extraction in the region. Researchers noted the importance of monitoring population numbers for the species, as well as studying the effects of [[oil spill]]-related petrochemicals on the snake's reproductive biology.<ref name="D"/><ref name="TI"/> Their high sensitivity to changes makes them an [[Bioindicator|indicator species]] for environmental health, highlighting the importance of assessing their populations.<ref name="TC">{{Cite news |last=Fry |first=Bryan G. |date=19 February 2024 |title=Scientists shocked to discover new species of green anaconda, the world's biggest snake |url=http://theconversation.com/scientists-shocked-to-discover-new-species-of-green-anaconda-the-worlds-biggest-snake-223549 |access-date=29 February 2024 |language=en-US |archive-date=29 February 2024 |archive-url=https://web.archive.org/web/20240229012503/https://theconversation.com/scientists-shocked-to-discover-new-species-of-green-anaconda-the-worlds-biggest-snake-223549 |url-status=live |website=[[The Conversation (website)|The Conversation]] }}</ref> It is believed that 20 to 31 percent of the northern green anaconda's habitat has been lost to [[deforestation]], with the number estimated to reach 40 percent by 2050.<ref name=UQ>{{Cite news |last=Blackwood |first=Emma |title=Giant new snake species identified in the Amazon |url=https://stories.uq.edu.au/news/2024/giant-new-snake-species-identified-in-amazon/index.html |access-date=2024-03-10 |date=20 February 2024 |language=en |journal=UQ News |publisher=[[University of Queensland]] |archive-date=23 February 2024 |archive-url=https://web.archive.org/web/20240223200601/https://stories.uq.edu.au/news/2024/giant-new-snake-species-identified-in-amazon/index.html |url-status=dead }}</ref>

==Notes==
{{notelist}}

==References==
{{Reflist|refs=
<ref name="NG">{{cite web|url=https://www.nationalgeographic.com/animals/article/new-green-anaconda-species-discovered|date=16 February 2024|title=The world's heaviest snake has been hiding a big secret|author=Jason Bittel|website=[[National Geographic]] |access-date=19 February 2024|archive-date=19 February 2024|archive-url=https://web.archive.org/web/20240219155233/https://www.nationalgeographic.com/animals/article/new-green-anaconda-species-discovered|url-status=live |url-access=registration}}</ref>
<ref name="D">{{cite journal |last1=Rivas |first1=Jesús |last2=De La Quintana |first2=Paola |last3=Mancuso |first3=Marco |last4=Pacheco |first4=Luis |last5=Rivas |first5=Gilson |last6=Mariotto |first6=Sandra |last7=Salazar-Valenzuela |first7=David |last8=Tepeña Baihua |first8=Marcelo |last9=Baihua |first9=Penti | last10=Burghardt |first10=Gordon |last11=Vonk |first11=Freek |last12=Hernandez |first12=Emil |last13=García-Pérez |first13=Juán Elías |last14=Fry |first14=Bryan |last15=Corey-Rivas |first15=Sarah |date=16 February 2024 |title=Disentangling the Anacondas: Revealing a New Green Species and Rethinking Yellows |journal=[[Diversity (journal)|Diversity]] |volume=16 |issue=2 |page=127 |doi=10.3390/d16020127 |doi-access=free }}</ref>
}}

{{Boidae}}
{{taxonbar|from1=Q124616509}}

[[Category:Apex predators]]
[[Category:Eunectes]]
[[Category:Fauna of the Amazon]]
[[Category:Reptiles described in 2024]]
[[Category:Reptiles of the Caribbean]]
[[Category:Reptiles of Colombia]]
[[Category:Reptiles of Ecuador]]
[[Category:Reptiles of Guyana]]
[[Category:Reptiles of Trinidad and Tobago]]
[[Category:Reptiles of Venezuela]]
[[Category:Snakes of South America]]
[[Category:Controversial taxa]]