Published May 30, 2024. Open access.

South American Pond Snake (Pseudoeryx plicatilis)

Reptiles of Ecuador | Serpentes | Colubridae | Pseudoeryx plicatilis

English common name: South American Pond Snake.

Spanish common names: Culebra acuática arrugada, culebras anguila.

Recognition: ♂♂ 87.6 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=76.2 cm. ♀♀ 144.1 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=127.7 cm..1,2 Pseudoeryx plicatilis is one of the most distinctive snakes of Amazonia. The body is robust and dorsally flattened with smooth dorsal scales and the head is compact, with small dorsally-oriented eyes.1,3 The dorsum is olive brown with faint pale yellowish brown dorsolateral stripes, bordered below by bold black lateral stripes (Fig. 1).1,35 The scales of the throat and belly are yellow (bright orange red in juveniles) with rows of black dots.1,3 No other snake in the Ecuadorian Amazon fits this description.

Figure showing an adult individual of Pseudoeryx plicatilis

Figure 1: Adult female of Pseudoeryx plicatilis from Limoncocha Biological Reserve, Sucumbíos province, Ecuador.

Natural history: Pseudoeryx plicatilis is a rarely seen aquatic snake that inhabits slow-moving black-water rivers, lagoons, ponds, swamps, and oxbow lakes along seasonally flooded lowland rainforests.17 South American Pond Snakes are nocturnal and their activites take place in water at different depths, including both active foraging and ambush behavior.1,3,8 Individuals have also been seen crawling on the forest floor as well as crossing roads, presumably migrating between aquatic habitats.1,8 The diet in P. plicatilis is primarily based on fish (including eels),1,2,8 but it also includes amphibians.5 This species has a variety of documented defensive behaviors.9 When handled, it typically remains calm without biting; instead, it hides the head under body coils, produces cloacal discharges, flattens the body dorso-ventrally, and exposes the brightly colored belly. The clutch size in this species is large, from 22 to 49 eggs.8,10,11 The female remains with the eggs during the incubation period.10,11

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..12 Pseudoeryx plicatilis is listed in this category due to its wide distribution, presence in a variety of protected areas, and presumed stable population densities.12 Although there is no information on the population trend of the South American Pond Snake at the national level, its numbers are expected to be declining alongside the decrease in water quality throughout the Amazonian river systems in northern Ecuador.

Distribution: Pseudoeryx plicatilis is widespread throughout Amazonia and peripheral areas in Bolivia, Brazil, Colombia, Ecuador (Fig. 2), French Guiana, Guyana, Paraguay, Perú, Suriname, and Venezuela, with a global range of ~1,088,089 km2.

Distribution of Pseudoeryx plicatilis in Ecuador

Figure 2: Distribution of Pseudoeryx plicatilis in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Pseudoeryx comes from the Greek words pseudo (=false)13 and Eryx (a genus of Old World sand boas), referring to the similarity between snakes of the two genera. The specific epithet plicatilis is a Latin word meaning “foldable,” probably refferring to the ventro-lateral skin fold of the alcohol-preserved holotype.

See it in the wild: In Ecuador, South American Pond Snakes are recorded no more than once every few years at any given locality. Recently, individuals of Pseudoeryx plicatilis have been sighted at Limoncocha Reserve and Añangu Lagoon. These snakes are most easily detected by scanning the shallow water along lagoons at night.

Authors: Tatiana Molina-Moreno,aAffiliation: Departamento de Biología, Universidad de los Llanos, Villavicencio, Colombia. Sophia Hurtado,bAffiliation: Universidad ICESI, Cali, Colombia. Andrés F. Aponte-Gutiérrez,cAffiliation: Grupo de Investigación en Ciencias de la Orinoquía, Universidad Nacional de Colombia sede Orinoquía, Arauca, Colombia.,dAffiliation: Fundación Biodiversa Colombia, Bogotá, Colombia. and Alejandro ArteagaeAffiliation: Tropical Herping (TH), Quito, Ecuador.

Photographer: Jose VieirafAffiliation: Tropical Herping (TH), Quito, Ecuador.,gAffiliation: ExSitu, Quito, Ecuador.

How to cite? Molina-Moreno T, Hurtado S, Aponte-Gutiérrez AF, Arteaga A (2024) South American Pond Snake (Pseudoeryx plicatilis). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/IGOK8377

Literature cited:

  1. Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
  2. Kaefer IL, Montanarin A (2010) Pseudoeryx plicatilis (South American Pond Snake): diet. Herpetological Review 41: 372.
  3. Duellman WE (2005) Cusco amazónico: the lives of amphibians and reptiles in an Amazonian rainforest. Cornell University Press, Ithaca, 433 pp.
  4. Pérez-Santos C, Moreno AG (1988) Ofidios de Colombia. Museo Regionale di Scienze Naturali, Torino, 517 pp.
  5. Starace F (1998) Serpents et amphisbènes de Guyane Française. Ibis Rouge Editions, Guadeloupe, 450 pp.
  6. Strüssmann C, Sazima I (1993) The snake assemblage of the Pantanal at Poconé, Western Brazil: faunal composition and ecological summary. Studies on Neotropical Fauna and Environment 28: 157–168.
  7. Scartozzoni RR, Trevine VC, Germano VJ (2010) Reptilia, Squamata, Serpentes, Dipsadidae, Pseudoeryx plicatilis (Linnaeus, 1758): new records and geographic distribution map. Check List 6: 534–537.
  8. Field notes, Reptiles of Ecuador book project.
  9. Cavalheri DG, Santos Carvalho P, Santana DJ (2021) Defensive repertory of Pseudoeryx plicatilis (Linnaeus, 1758) in the Pantanal, Mato Grosso do Sul, Brazil. Cuadernos de Herpetología 35: 161–164.
  10. Frota JG, Yuki RN (2005) Pseudoeryx plicatilis plicatilis (Eel snake): reproduction. Herpetological Review 36: 326.
  11. Braz H, Scartozzoni R, Almeida-Santos SM (2016) Reproductive modes of the South American water snakes : a study system for the evolution of viviparity in squamate reptiles. Zoologischer Anzeiger 263: 33–44. DOI: 10.1016/j.jcz.2016.04.003
  12. Gagliardi G, Nogueira CC, Embert D, Cisneros-Heredia DF, Gonzales L, Catenazzi A, Schargel W, Rivas G, Silveira AL, Argôlo AJS, Abrahão CR, Strüssmann C, Loebmann D, Barbo FE, Franco FL, Costa GC, de Moura GJB, Zaher HD, Borges-Martins M, Martins MRC, Oliveira ME, Hoogmoed MS, Marques OAV, Passos PGH, Bérnils RS, Kawashita-Ribeiro RA, Sawaya RJ, da Costa TBG (2019) Pseudoeryx plicatilis. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2019-2.RLTS.T177528A44951789.en
  13. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.

Appendix 1: Locality data used to create the distribution map of Pseudoeryx plicatilis in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

ColombiaCaquetáMilániNaturalist; photo examined
ColombiaPutumayoRío CocayaiNaturalist; photo examined
EcuadorOrellanaComunidad Chiru IslaNogueira et al. 2019
EcuadorOrellanaRío TambocochaNogueira et al. 2019
EcuadorOrellanaRío TiputiniPazmiño-Otamendi 2021
EcuadorPutumayoRío PutumayoGeopark Colombia S.A.S.
EcuadorSucumbíosConfluencia del Río Jivino y Río NapoNogueira et al. 2019
EcuadorSucumbíosEntre bocana Cuyabeno y ZábaloNogueira et al. 2019
EcuadorSucumbíosEstación PUCE en CuyabenoNogueira et al. 2019
EcuadorSucumbíosLimococha Biological ReserveThis work; Fig. 1
EcuadorSucumbíosNapo Wildlife CenterScartozzoni et al. 2010
EcuadorSucumbíosTarapoaScartozzoni et al. 2010
PerúLoretoCentro UniónDixon & Soini 1986
PerúLoretoIquitosDixon & Soini 1986
PerúLoretoMishanaDixon & Soini 1986
PerúLoretoMoroponDixon & Soini 1986