Published April 25, 2024. Open access.

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White-lipped Marsh-Snake (Erythrolamprus chrysostomus)

Reptiles of Ecuador | Serpentes | Colubridae | Erythrolamprus chrysostomus

English common name: White-lipped Marsh-Snake.

Spanish common name: Culebra de labios dorados.

Recognition: ♂♂ 72.0 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=57.9 cm. ♀♀ 90.1 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=73.3 cm..1 Erythrolamprus chrysostomus is a medium-sized snake having smooth dorsal scales arranged in 17 rows at mid-body.13 The dorsal color pattern of juveniles and hatchlings is light brown with a series of dark brown or black spots that may coalesce into a dorsolateral stripe that is more evident on the tail (Fig. 1). The throat and chin are black with scattered contrasting light spots and streaks, while the ventral side is yellowish white with dense black bars forming a checkerboard pattern.14 The adults have a more uniformly olive brown dorsal coloration with dark-edged scales, lacking contrasting spots and stripes.13 In both adults and juveniles, there is a conspicuous black-edged white stripe on the lips.14 This species is easily differentiated from other Erythrolamprus by virtue of its white labial stripe, although this may become fain in older specimens. From E. reginae, it differs by having a checkered, rather than immaculate throat pattern. From Taeniophallus brevirostris, it differs by lacking undulating cream dorsolateral bands.2

Figure showing a juvenile individual of Erythrolamprus chrysostomus

Figure 1: Juvenile of Erythrolamprus chrysostomus from Suchipakari Lodge, Napo province, Ecuador.

Natural history: Erythrolamprus chrysostomus is an extremely rare diurnal and terrestrial to semi-aquatic snake that inhabits rainforests, which may be terra-firme or seasonally flooded, usually in or around bodies of water.13 White-lipped Marsh-Snakes also occur in pastures. They are typically active during the day on leaf-litter or in streams.5,6 White-lipped Marsh-Snakes have an aglyphous dentition, meaning their teeth lack specialized grooves to deliver venom.7 They are active hunters having a diet composed of fish6,8 and frogs.9 Marsh Snakes are usually calm and try to flee when threatened, relying mostly on crypsis as a primary defense mechanism.5

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Conservation: Least Concern Believed to be safe from extinction given current circumstances.. Erythrolamprus chrysostomus is considered by some authors to be a subspecies of E. miliaris. Therefore, it has not been independently evaluated by the IUCN Red List. Here, it is proposed to be included in the LC category mainly on the basis of the species’ wide distribution, occurrence in protected areas, and presumed large stable populations.

Distribution: Erythrolamprus chrysostomus is widely distributed throughout the western Amazon basin in Brazil, Colombia, Ecuador (Fig. 2), and Peru, with scattered records along the Amazon River all the way to the eastern Amazon Basin.

Distribution of Erythrolamprus chrysostomus in Ecuador

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

Etymology: The name Erythrolamprus, which comes from the Greek words erythros (=red) and lampros (=brilliant),10 refers to the bright red body rings of some snakes in this genus (such as E. aesculapii). The specific epithet chrysostomus comes from the Greek chrysos (=gold) and stoma (=mouth).10 It refers to the bright lip coloration.

See it in the wild: White-lipped Marsh-Snakes are recorded no more than once every few years. The area having the greatest number of observations of E. chrysostomus is the the town of Macum. Active snakes can be found by walking along forest trails during the day.

Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.

Photographer: Jose VieirabAffiliation: Tropical Herping (TH), Quito, Ecuador.,cAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2024) White-lipped Marsh-Snake (Erythrolamprus chrysostomus). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/SHSJ8622

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. Duellman WE (1978) The biology of an equatorial herpetofauna in Amazonian Ecuador. Publications of the Museum of Natural History, University of Kansas 65: 1–352.
  3. Dixon JR (1983) Taxonomic status of the South American snakes Liophis miliaris, L. amazonicus, L. chrysostomus, L. mossoriensis and L. purpurans. Copeia 1983: 791–802.
  4. Cope ED (1868) An examination of the Reptilia and Batrachia obtained by the Orton Expedition to Equador and the Upper Amazon, with notes on other species. Proceedings of the Academy of Natural Sciences of Philadelphia 20: 96–140.
  5. Field notes, Reptiles of Ecuador book project.
  6. Tipantiza-Tuguminago L, Medrano-Vizcaíno P, Argüello P, Auqui E (2019) Erythrolamprus miliaris chrysostomus (Military Ground Snake). Herpetological Review 50: 800.
  7. Hurtado-Gómez JP (2016) Systematics of the genus Erythrolamprus Boie 1826 (Serpentes: Dipsadidae) based on morphological and molecular data. PhD thesis, Universidade de São Paulo, 62 pp.
  8. Cadena-Ortiz H, Barahona A, Bahamonde-Vinueza D, Brito J (2017) Anecdotal predation events of some snakes in Ecuador. Herpetozoa 30: 93–96.
  9. Cunha OR, do Nascimento FP (1994) Ofídios da Amazônia. As cobras da região leste do Pará. Boletim do Museu Paraense Emílio Goeldi 9: 1–191.
  10. 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 Erythrolamprus chrysostomus in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

ColombiaCaquetáFlorenciaCárdenas Hincapié & Lozano Bernal 2023
ColombiaCaquetáLa RastraCárdenas Hincapié & Lozano Bernal 2023
ColombiaMetaEl JardínNogueira et al. 2019
ColombiaPutumayoPuerto AsísCárdenas Hincapié & Lozano Bernal 2023
ColombiaPutumayoVereda La PalmeraNogueira et al. 2019
EcuadorMorona SantiagoMacumaiNaturalist; photo examined
EcuadorNapoFinca FischerTCWC 65519; VertNet
EcuadorNapoRío NapoCope 1868
EcuadorNapoSuchipakari LodgeThis work; Fig. 1
EcuadorOrellanaAlta FlorenciaPazmiño-Otamendi & Rodríguez-Guerra 2022
EcuadorOrellanaComunidad San CarlosCadena-Ortiz et al. 2017
EcuadorOrellanaEl CocaDixon 1983
EcuadorOrellanaEstero AndiaTipantiza-Tuguminago et al. 2019
EcuadorOrellanaLoretoUSNM 232829; VertNet
EcuadorOrellanaWatiNogueira et al. 2019
EcuadorPastazaCabeceras del BobonazaNogueira et al. 2019
EcuadorPastazaRío OglánDixon 1983
EcuadorPastazaRío Pastaza SMNS 5428; VertNet
EcuadorPastazaRío VillanoUSNM 232827; VertNet
EcuadorPastazaShellNogueira et al. 2019
EcuadorSucumbíosLa Selva LodgeNogueira et al. 2019
EcuadorSucumbíosLimoncochaDixon 1983
EcuadorSucumbíosMonte CarmeloDixon 1983
EcuadorSucumbíosPlayas de CuyabenoTorres-Carvajal & Hinojosa 2020
EcuadorSucumbíosSanta Cecilia Duellman 1978
PerúLoretoCentro UniónDixon 1983
PerúLoretoMoroponDixon 1983
PerúLoretoTeniente López, 12 km NE ofMCZ 160097; VertNet