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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.4,5 The eyes of this species are small, vestigial, but functional; hence the local name culebra ciega (which means “blind snake”). In western Ecuador, there is no other snake or lizard that looks remotely similar to A. 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. seen1,6 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
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 Panama 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 difficult to see in Ecuador. Individuals are found no more than once or twice every few months at any given locality. Encounters usually take place after heavy rains when the lizards emerge from their burrows. The area having the greatest number of recent observations in Ecuador is the immediate surrounding of the town Puerto Quito, Pichincha province.
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 VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador.
Editor: Alejandro ArteagacAffiliation: Biodiversity Field Lab, Khamai Foundation, Quito, Ecuador.
Photographers: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador. and Sebastián Di DoménicodAffiliation: Keeping Nature, Bogotá, Colombia.
How to cite? Vieira J (2021) Variable Worm-Lizard (Amphisbaena varia). In: Arteaga A, Bustamante L, Vieira J, Guayasamin JM (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 El Jardín de los Sueños | Photo by Christophe Pellet |
| 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 | Vía La Avanzada–Piñas | DHMECN 594 |
| Ecuador | Esmeraldas | Bilsa Biological Station | Ortega-Andrade et al. 2010 |
| Ecuador | Esmeraldas | Canandé Biological Reserve | This work |
| Ecuador | Esmeraldas | Durango | This work |
| Ecuador | Esmeraldas | Durango, 5.3 km NW of | Online multimedia |
| Ecuador | Esmeraldas | Gualpí | This work |
| Ecuador | Esmeraldas | Playón de San Francisco | Field notes of Luis Coloma |
| Ecuador | Esmeraldas | Quinindé, 35 km NE of | MHNG 2086.081 |
| Ecuador | Esmeraldas | Reserva Biológica Jevon Forest | iNaturalist |
| Ecuador | Esmeraldas | San Miguel de los Bancos | MHNG 2246.090 |
| Ecuador | Guayas | Bucay | Vanzolini 2002 |
| Ecuador | Guayas | Campamento Quizás Hoy | This work |
| Ecuador | Guayas | Naranjal, 8 km NE of | This work |
| Ecuador | Guayas | Pagua, 15 km NNE of | This work |
| Ecuador | Guayas | Río Daule | MCZ 3571 |
| Ecuador | Los Ríos | Hacienda La Clementina | MHNG 1078.020 |
| Ecuador | Los Ríos | Jauneche | Photo by Keyko Cruz |
| Ecuador | Los Rios | Centro Científico Río Palenque | MCZ 156878 |
| 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 | El Carmen | Torres-Carvajal et al. 2019 |
| Ecuador | Manabí | Reserva Jama-Coaque | Lynch et al. 2016 |
| Ecuador | Manabí | Sube y Baja | iNaturalist |
| Ecuador | Pichincha | Alluriquín | MHNG 2246.092 |
| Ecuador | Pichincha | Escalera | iNaturalist |
| Ecuador | Pichincha | Hacienda Espinosa | CAS 13296 |
| Ecuador | Pichincha | Hostería Selva Virgen | This work |
| Ecuador | Pichincha | Puerto Quito | MHNG 2246.091 |
| Ecuador | Pichincha | Puerto Quito, 2 km NW of | This work |
| Ecuador | Pichincha | Puerto Quito, 5 km E of | This work |
| Ecuador | Pichincha | Quevedo, 10 mi W of | MSUMHE.1374 |
| Ecuador | Pichincha | Rancho Suamox | Photo by Rafael Ferro |
| Ecuador | Pichincha | Reserva Mashpi Shungo | iNaturalist |
| Ecuador | Pichincha | Saguangal | DHMECN 4491 |
| Ecuador | Pichincha | Santo Domingo de los Colorados | Vanzolini 2002 |
| Ecuador | Pichincha | Santo Domingo de los Colorados, 18 km SE of | MCZ 156883 |
| Ecuador | Santo Domingo de los Tsáchilas | Chorrera del Diablo | Field notes of Elicio Tapia |
| Ecuador | Santo Domingo de los Tsáchilas | La Unión del Toachi | This work |
| Ecuador | Santo Domingo de los Tsáchilas | Otongachi Reserve | This work |
| Ecuador | Santo Domingo de los Tsáchilas | Río Baba | UIMNH 66649 |
| Ecuador | Santo Domingo de los Tsáchilas | Santo Domingo, 12 km SW of | This work |