Published May 12, 2018. Updated April 12, 2024. Open access.

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Vermiculated Snail-eating Snake (Dipsas vermiculata)

Reptiles of Ecuador | Serpentes | Colubridae | Dipsas vermiculata

English common name: Vermiculated Snail-eating Snake.

Spanish common name: Caracolera vermiculada.

Recognition: ♂♂ 73.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=50.1 cm. ♀♀ 70.1 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=50.1 cm..1 Dipsas vermiculata is the only snake in its area of distribution having the following combination of characters: dorsal scales arranged in 13 rows at mid-body, vertebral scale row distinctively wider than adjacent rows, light brown (yellow in juveniles) dorsum with 36–45 black to dark-brown blotches, and head strongly vermiculated with light yellowish pigment (Fig. 1).13 This species differs from D. indica by having a pointed, instead of blunt, snout and a brown, instead of gray, dorsum.4 From D. welborni, it differs by having the prefrontal scales fused into a single scale.1

Figure showing variation among individuals of Dipsas vermiculata

Figure 1: Individuals of Dipsas vermiculata from Ecuador: Reserva Narupa, Napo province (); Reserva Río Bigai, Napo province (); Tamandúa Reserve, Pastaza province (). j=juvenile.

Natural history: Dipsas vermiculata is a nocturnal snake that inhabits old-growth to moderately disturbed rainforests, occurring in lower densities, or not at all, in forest-edge situations.5 Vermiculated Snail-Eaters are active at night, especially if it is raining or drizzling.5 Their movements throught the foliage are slow, graceful, and generally occur during the first hours of the night on vegetation 0.4–4.5 m above the ground.5 During the day, they remain coiled under rocks or inside bromeliads up to 2 m above the ground.5 Nothing is know about the diet in this species, but snakes of the genus Dipsas in general feed almost exclusively on snails and slugs. Although some snail-eaters produce saliva that is toxic to mollusks,6 these snakes are considered harmless to humans. They never attempt to bite, resorting instead to musking and flattening the body while expanding the head to simulate a triangular shape.5,7

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..8 Dipsas vermiculata is listed in this category because the species is distributed over an area that retains the majority (approximately 87%)9,10 of its forest cover, and therefore, is considered to be facing no major immediate threats of extinction.

Distribution: Dipsas vermiculata is native to an area of approximately 50,899 km2 along the Amazonian foothills of the Andes in Ecuador (Fig. 2) and Colombia.

Distribution of Dipsas vermiculata in Ecuador

Figure 2: Distribution of Dipsas vermiculata in Ecuador. The star corresponds to the type locality: Chichirota, Pastaza province. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The name Dipsas comes from the Greek dipsa (=thirst)11 and probably refers to the fact that the bite of these snakes was believed to cause intense thirst. The specific epithet vermiculata is a Latin word meaning “wormlike.”11 It refers to the color pattern of the head of this snake.

See it in the wild: Vermiculated Snail-eating Snakes can be seen at a rate of about once every few nights, especially after a rainy day in forested areas throughout their area of distribution in Ecuador. Prime localities for this species in Ecuador include Reserva Narupa and Reserva Río Anzu.

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) Vermiculated Snail-eating Snake (Dipsas vermiculata). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/KXFD1747

Literature cited:

  1. Arteaga A, Batista A (2023) A consolidated phylogeny of snail-eating snakes (Serpentes, Dipsadini), with the description of five new species from Colombia, Ecuador, and Panama. ZooKeys 1143: 1–49. DOI: 10.3897/zookeys.1143.93601
  2. Peters JA (1960) The snakes of the subfamily Dipsadinae. Miscellaneous Publications, Museum of Zoology, Univesity of Michigan 114: 1–224.
  3. Vera-Pérez LE (2020) Dipsas vermiculata Peters, 1960 (Squamata, Colubridae): First country record from Colombia, with description of its hemipenial morphology and comments on its distribution and diagnosis. Check List 16: 527–533. DOI: 10.15560/16.3.527
  4. 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.
  5. Field notes, Reptiles of Ecuador book project.
  6. De Oliveira L, Jared C, da Costa Prudente AL, Zaher H, Antoniazzi MM (2008) Oral glands in dipsadine “goo-eater” snakes: morphology and histochemistry of the infralabial glands in Atractus reticulatus, Dipsas indica, and Sibynomorphus mikanii. Toxicon 51: 898–913. DOI: 10.1016/j.toxicon.2007.12.021
  7. Cadle JE, Myers CW (2003) Systematics of snakes referred to Dipsas variegata in Panama and Western South America, with revalidation of two species and notes on defensive behaviors in the Dipsadini (Colubridae). American Museum Novitates 3409: 1–47.
  8. Cisneros-Heredia DF, Yánez-Muñoz M, Almendáriz A, Valencia J, Segovia J, Torres C (2016) Dipsas vermiculata. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2016-1.RLTS.T50951315A50951320.en
  9. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  10. IDEAM (2014) Mapa de cobertura de la tierra adaptada para Colombia.
  11. 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 Dipsas vermiculata in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used. Asterisk (*) indicates type locality.

ColombiaCaquetáParque Nacional Alto Fragua Indi-WasiVera-Perez 2020
ColombiaPutumayoReserva La Isla EscondidaArteaga & Batista 2023
EcuadorMorona SantiagoChiguazaHarvey 2008
EcuadorMorona SantiagoRefugio MarantianArteaga & Batista 2023
EcuadorMorona SantiagoTurulaPeters 1960
EcuadorNapoCuya Wasi, 3 km SW ofiNaturalist; photo examined
EcuadorNapoNarupa Biological ReserveArteaga & Batista 2023
EcuadorNapoReserva Colonso ChalupasArteaga & Batista 2023
EcuadorNapoReserva Río BigaiThis work; Fig. 1
EcuadorNapoRío SaladoArteaga & Batista 2023
EcuadorNapoRío Salado, 14.7 km NE of Harvey 2008
EcuadorOrellanaCabeceras del Río NapoHarvey 2008
EcuadorOrellanaReserva Río BigalArteaga & Batista 2023
EcuadorPastazaChichirota*Peters 1960
EcuadorPastazaKallanaArteaga et al. 2018
EcuadorPastazaPuyoHarvey 2008
EcuadorPastazaPuyo, 1 km W ofArteaga & Batista 2023
EcuadorPastazaRío Anzu Ecological ReserveArteaga & Batista 2023
EcuadorPastazaRío ShilcayacuHarvey 2008
EcuadorPastazaTamandúa ReserveArteaga & Batista 2023
EcuadorPastazaTzarentzaArteaga et al. 2018
EcuadorSucumbíosEl ReventadorArteaga et al. 2018