Variable Worm-Lizard (Amphisbaena varia)

Reptiles of Ecuador | Amphisbaenia | Amphisbaena varia

English common name: Variable Worm-Lizard.

Spanish common names: Pudridora del Chocó, pudridora, culebra ciega de la costa (Ecuador); lagarto gusano moteado, lagartija gusano, tatacoa (Colombia); lagarto de dos cabezas (Panamá).

Recognition: ♂♂ 42.4 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=40.4 cm. ♀♀ 46.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=40.5 cm..^1,2 The Variable Worm-Lizard (Amphisbaena varia) is a unique reptile, neither lizard nor snake, it belongs to the suborder Amphisbaenia.³ It can be easily distinguished by the presence of the following two features: white or light pink background color with very dense black markings that resemble a checkerboard and scales arranged in rings around the body (Fig. 1).^4,5 The eyes of this species are small, vestigial, but functional; hence the local name culebra ciega (=blind snake). In western Ecuador, there is no other snake or lizard that looks remotely similar to A. varia.

Figure variation among individuals of Amphisbaena varia

Figure 1: Individuals of Amphisbaena varia from Durango () and Gualpí (), Esmeraldas province, Ecuador.

Natural history: Amphisbaena varia is a rarelyTotal average number of reported observations per locality less than ten. seen^1,6 fossorial and primarily nocturnal reptile that spends most of the time in galleries built by the animal itself.¹ Variable Worm-Lizards come to the surface only occasionally, especially during twilight or at night. Some individuals have been seen moving on soil or leaf-litter during the day, particularly when their underground burrows are flooded.^1,7 One individual was found in a presumably self-made burrow under a large stump.¹ Amphisbaena varia can be found in old growth to moderately disturbed rainforests, as well as in clearings, urban and peri-urban areas, plantations,^1,7 compost bins in rural gardens,⁷ and inside houses.⁸ This reptile has a rectilinear form of locomotion that resembles the way a worm moves.⁹ As a defense mechanism, Variable Worm-Lizards react by trying to flee or bury themselves quickly. If captured, they contract their body, bite,¹ or shed the tail.⁷ There is a record of an Anchor Coralsnake (Micrurus ancoralis) preying upon an individual of this species.¹⁰ Amphisbaena varia is an oviparous species, but the nesting sites are not known. Other Amphisbaena lay eggs inside the nests of ants or termites.¹¹

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..^12,13 Amphisbaena varia is listed this category because it is widely distributed, especially in areas that have not been heavily affected by deforestation, like the Colombian Pacific coast, and it is unlikely to be declining fast enough to qualify for a threatened category. However, the species could suffer local population declines due to habitat destruction and the excessive use of pesticides that decimate insect populations, such as ants or termites, which perhaps are crucial in the life cycle of A. varia. Vehicular traffic is another source of mortality for Variable Worm-Lizards.^1,7 Given their terrestrial habits and their low ability to move on the ground, these animals cannot easily dodge cars and are frequently run over.

Distribution: Amphisbaena varia occurs in the Mesoamerican lowlands of eastern Central America, the Chocó region of northwestern South America, and the valleys of the rivers Magadalena and Cauca in Colombia. The species occurs from central Panamá to southwestern Ecuador, where it has been recorded at elevations between 6 and 1090 m (Fig. 2).

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

Etymology: The name Amphisbaena is a Latin word used to refer to a “fabulous serpent having a head at each end.”¹⁴ In this species, the head and the tail are very similar, which can give the illusion that the animal is advancing backwards. The specific epithet varia comes from the Latin word varius, which means “diverse.” It probably refers to the varied dorsal pattern across individuals of this species.

See it in the wild: Variable Worm-Lizards are usually encountered right after heavy rains. In Ecuador, a prime location for this species is the forests around Puerto Quito.

Acknowledgments: Special thanks to Lina Parra for helping compile some of the information used in this account. Thanks to Matteo Espinosa, Eric Osterman, and Frank Pichardo for their help finding this species in the field.

Special thanks to Tim Paine for symbolically adopting the Variable Worm-Lizard and helping bring the Reptiles of Ecuador book project to life.

Click here to adopt a species.

Author: Jose Vieira^aAffiliation: Tropical Herping (TH), Quito, Ecuador.^,^bAffiliation: ExSitu, Quito, Ecuador.

Editor: Alejandro Arteaga^cAffiliation: Fundación Khamai, Reserva Arlequín, Ecoruta Paseo del Quinde km 56, Santa Rosa de Mindo, Pichincha 171202, Ecuador.

Photographers: Jose Vieira^aAffiliation: Tropical Herping (TH), Quito, Ecuador.^,^bAffiliation: ExSitu, Quito, Ecuador. and Sebastián Di Doménico^dAffiliation: Keeping Nature, Bogotá, Colombia.

How to cite? Vieira J (2024) Variable Worm-Lizard (Amphisbaena varia). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com. DOI: 10.47051/YXFM2018

Literature cited:

Ray JM (2015) Amphisbaena varia (Linnaeus, 1758) (Amphisbaenia: Amphisbaenidae): new distributional records from western Panamá. Herpetology Notes 8: 191–196.
Vanzolini PE (1951) Contributions to the knowledge of the Brasilian lizards of the family Amphisbaenidae Gray, 1825. 6. On the geographical distribution and differentiation of Amphisbaena fuliginosa Linné. Bulletin of the Museum of Comparative Zoology 106: 1–67.
Gans C (2005) Checklist and bibliography of the Amphisbaenia of the world. Bulletin of the American Museum of Natural History 289: 1–30.
Vanzolini PE (2002) A second note on the geographical differentiation of Amphisbaena fuliginosa L., 1758 (Squamata, Amphisbaenidae), with a consideration of the forest refuge model of speciation. Anais da Academia Brasileira de Ciências 74: 609–648.
Yánez-Muñoz M, Meza-Ramos P, Ramírez S, Reyes-Puig J, Oyagata L (2009) Anfibios y reptiles del Distrito Metropolitano de Quito (DMQ). In: Yánez-Muñoz MH, Moreno-Cárdenas PA, Mena-Valenzuela P (Eds) Guía de campo de los pequeños vertebrados del Distrito Metropolitano de Quito (DMQ). Museo Ecuatoriano de Ciencias Naturales (MECN), Quito, 9–52.
Field notes, Reptiles of Ecuador book project.
Jose Vieira, field observation.
Video by Cody Conway.
Gans C (1969) Amphisbaenians – Reptiles specialized for a burrowing existence. Endeavor 28: 146–151.
Cisneros-Heredia DF (2005) Predation upon Amphisbaena fuliginosa LINNAEUS, 1758 by Micrurus ancoralis (JAN, 1872). Herpetozoa 18: 93–94.
Andrade DV, Nascimento LB, Abe AS (2006) Habits hidden underground: a review on the reproduction of the Amphisbaenia with notes on four neotropical species. Amphibia-Reptilia 27: 207–217. DOI: 10.1163/156853806777239995
Reyes-Puig C (2015) Un método integrativo para evaluar el estado de conservación de las especies y su aplicación a los reptiles del Ecuador. MSc thesis, Pontificia Universidad Católica del Ecuador, 73 pp.
Carrillo E, Aldás A, Altamirano M, Ayala F, Cisneros-Heredia DF, Endara A, Márquez C, Morales M, Nogales F, Salvador P, Torres ML, Valencia J, Villamarín F, Yánez-Muñoz M, Zárate P (2005) Lista roja de los reptiles del Ecuador. Fundación Novum Millenium, Quito, 46 pp.
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 Amphisbaena varia in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

Country	Province	Locality	Source
Ecuador	Cotopaxi	Bosque Privado JDLS	Photo by Christophe Pellet
Ecuador	Cotopaxi	Moraspungo	Pazmiño-Otamendi & Rodríguez-Guerra 2020
Ecuador	El Oro	Arenillas	Photo by Carlos Patricio
Ecuador	El Oro	Cascadas de Manuel	Garzón-Santomaro et al. 2019
Ecuador	El Oro	Cordillera de Chilla	Yánez-Muñoz et al. 2004
Ecuador	El Oro	Reserva Biológica Buenaventura	Garzón-Santomaro et al. 2019
Ecuador	El Oro	San Antonio	iNaturalist; photo examined
Ecuador	Esmeraldas	Bilsa Biological Station	Ortega-Andrade et al. 2010
Ecuador	Esmeraldas	Canandé Biological Reserve	Reptiles of Ecuador database
Ecuador	Esmeraldas	Durango	Reptiles of Ecuador database
Ecuador	Esmeraldas	Durango, 5.3 km NW of	Online multimedia
Ecuador	Esmeraldas	Gualpí	Reptiles of Ecuador database
Ecuador	Esmeraldas	Pichiyacu	Pazmiño-Otamendi & Rodríguez-Guerra 2020
Ecuador	Esmeraldas	Playón de San Francisco	Field notes of Luis Coloma
Ecuador	Esmeraldas	Quinindé, 35 km NE of	MHNG 2086.081; collection database
Ecuador	Esmeraldas	Reserva Biológica Jevon Forest	iNaturalist; photo examined
Ecuador	Esmeraldas	San Miguel de los Bancos	MHNG 2246.090; collection database
Ecuador	Esmeraldas	Viche	Pazmiño-Otamendi & Rodríguez-Guerra 2020
Ecuador	Guayas	Bucay	Vanzolini 2002
Ecuador	Guayas	Campamento Quizás Hoy	Reptiles of Ecuador database
Ecuador	Guayas	Naranjal, 8 km NE of	Reptiles of Ecuador database
Ecuador	Guayas	Pagua, 15 km NNE of	Reptiles of Ecuador database
Ecuador	Guayas	Río Daule	MCZ 3571; VertNet
Ecuador	Los Ríos	Centro Científico Río Palenque	MCZ 156878; VertNet
Ecuador	Los Ríos	Hacienda La Clementina	MHNG 1078.020; collection database
Ecuador	Los Ríos	Jauneche	Photo by Keyko Cruz
Ecuador	Los Rios	Pichilingue	Vanzolini 2002
Ecuador	Manabí	Bosque Seco Lalo Loor	Hamilton et al. 2005
Ecuador	Manabí	Cerro Pata de Pájaro	Photo by Carlos Robles
Ecuador	Manabí	Los Senderos de Tachila	Photo by Tina Swan
Ecuador	Manabí	El Carmen	Torres-Carvajal et al. 2019
Ecuador	Manabí	Reserva Jama-Coaque	Lynch et al. 2016
Ecuador	Manabí	Sube y Baja	iNaturalist; photo examined
Ecuador	Pichincha	Alluriquín	MHNG 2246.092; collection database
Ecuador	Pichincha	Escalera	iNaturalist; photo examined
Ecuador	Pichincha	Hacienda Espinosa	CAS 13296; VertNet
Ecuador	Pichincha	Hostería Selva Virgen	Reptiles of Ecuador database
Ecuador	Pichincha	Puerto Quito	MHNG 2246.091; collection database
Ecuador	Pichincha	Puerto Quito, 2 km NW of	Reptiles of Ecuador database
Ecuador	Pichincha	Puerto Quito, 5 km E of	Reptiles of Ecuador database
Ecuador	Pichincha	Quevedo, 10 mi W of	MSUMHE.1374
Ecuador	Pichincha	Rancho Suamox	Photo by Rafael Ferro
Ecuador	Pichincha	Reserva Mashpi Shungo	iNaturalist; photo examined
Ecuador	Pichincha	Saguangal	Yánez-Muñoz et al. 2009
Ecuador	Pichincha	Santo Domingo de los Colorados	Vanzolini 2002
Ecuador	Pichincha	Santo Domingo de los Colorados, 18 km SE of	MCZ 156883; VertNet
Ecuador	Santo Domingo de los Tsáchilas	Chorrera del Diablo	Field notes of Elicio Tapia
Ecuador	Santo Domingo de los Tsáchilas	La Unión del Toachi	Reptiles of Ecuador database
Ecuador	Santo Domingo de los Tsáchilas	Otongachi Reserve	Reptiles of Ecuador database
Ecuador	Santo Domingo de los Tsáchilas	Río Baba	UIMNH 66649; collection database
Ecuador	Santo Domingo de los Tsáchilas	Santo Domingo, 12 km SW of	Reptiles of Ecuador database