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Speckled Worm-Lizard (Amphisbaena bassleri)
Reptiles of Ecuador | Amphisbaenia | Amphisbaena bassleri
English common name: Speckled Worm-Lizard.
Spanish common names: Pudridora amazónica, lagarto gusano moteado.
Recognition: ♂♂ 41.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=36.4 cm. ♀♀ 52.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=45 cm..1–3 The Speckled Worm-Lizard (Amphisbaena bassleri) is a unique reptile, neither lizard nor snake, it belongs to the suborder Amphisbaenia. It can be easily distinguished by having scales arranged in rings and by its checkerboard coloration (Fig. 1).4 The eyes are vestigial, but functional; hence the local name culebra ciega (which means “blind snake”). The only other amphisbaenian in Amazonian Ecuador is A. alba, a reptile characterized by its entirely yellowish cream coloration and by lacking an autotomy ring on the tail (the autotomy ring corresponds to where the vertebrae brake during the shedding of the tail; it is present in A. bassleri).5 Amphisbaena bassleri differs from the snake-like lizard Bachia trisanale by its larger size and the absence of limbs.6
Figure 1: Juvenile of Amphisbaena bassleri from Tena, Napo province, Ecuador.
Natural history: Amphisbaena bassleri is a rareTotal average number of reported observations per locality less than ten. reptile in old-growth rainforests7,8 in Ecuador, but is frequentlyRecorded weekly in densities below five individuals per locality. seen in peri-urban areas, plantations, roadsides, cultivated fields, and forest edge situations.9–11 Speckled Worm-Lizards are fossorial and emerge to the surface only occasionally, especially when their underground burrows are flooded.9 They can also be observed on the surface during sunny days.12 Their body is extremely muscular and allows them to dig their own tunnels. These reptiles have a rectilinear form of locomotion that resemble the way a worm moves. Their diet is insectivorous and includes ants, termites, millipedes,7,8 and earthworms.12 Individuals defend themselves by fleeing or burying themselves quickly;10 if captured, they can twist their body, bite, and shed parts of the tail.8 They are also capable of swimming for more than 10 min and remain submerged for at least 30 seconds.13 However, some specimens have been found dead after floods, apparently drowned.9 These worm-lizards are preyed upon by coral snakes. In the wild, by Micrurus obscurus;14 in captivity, a M. helleri was fed dead specimens of A. bassleri.12 It is an oviparous species although the oviposition site is unknown.15 Other Amphisbaena species lay eggs inside the nests of ants or termites.15
Conservation: Least Concern Believed to be safe from extinction given current circumstances..16,17 Amphisbaena bassleri is listed in this category because the species is widely distributed and is believed to be facing no major immediate extinction threats. However, some populations are probably declining due to habitat destruction and the excessive use of pesticides that decimate insect populations, such as ants and termites, which are crucial in the life cycle of amphisbaenians in general.18 Vehicular traffic is another source of mortality for individuals of this species.9,11 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 bassleri is native to the upper Amazon basin in Colombia, Ecuador, and Perú. In Ecuador, the species has been recorded at elevations between 125 and 1409 m (Fig. 2).
Figure 2: Distribution of Amphisbaena bassleri 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.”19 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 bassleri honors Dr. Harvey Bassler (1883–1950), an American geologist and zoologist whose collections contributed greatly to the knowledge of Peruvian herpetology.2
See it in the wild: Speckled 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 reptiles emerge from their burrows. The area having the greatest number of recent observations in Ecuador is the segment of the troncal Amazónica connecting the cities Tena and Zamora.
Acknowledgments: Special thanks to Lina Parra for helping compile some of the information used in this account. Thanks to Darwin Núñez for providing anecdotal data used in this account.
Special thanks to Kelly Irwin for symbolically adopting the Speckled Worm-Lizard and helping bring the Reptiles of Ecuador book project to life.
Click here to adopt a species.
Authors: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador. and Alejandro ArteagacAffiliation: Khamai Foundation, Quito, Ecuador.
Photographer: Alejandro ArteagacAffiliation: Khamai Foundation, Quito, Ecuador.
How to cite? Vieira J, Arteaga A (2023) Speckled Worm-Lizard (Amphisbaena bassleri). 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/AOQC2127
Literature cited:
- Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
- 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.
- Field notes, Reptiles of Ecuador book project.
- 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.
- Gans C (1962) A redefinition and a bibliography of Amphisbaena alba Linné. American Museum Novitates 2105: 1–31.
- Peters JA, Donoso-Barros R (1970) Catalogue of the Neotropical Squamata: part II, lizards and amphisbaenians. Bulletin of the United States National Museum, Washington, D.C., 293 pp.
- 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.
- Vitt LJ, De la Torre S (1996) A research guide to the lizards of Cuyabeno. Pontificia Universidad Católica del Ecuador, Quito, 165 pp.
- Van der Hoek Y, Jarrín-V P (2017) A note on the prevalence of Amphisbaena bassleri L. 1758 (Squamata, Amphisbaenidae) in a study of road ecology in the western Amazon, near Tena (Ecuador). Herpetology Notes 10: 497–498.
- Jose Vieira, field observation.
- Filius J, van der Hoek Y, Jarrín‐V P, van Hooft P (2020) Wildlife roadkill patterns in a fragmented landscape of the Western Amazon. Ecology and Evolution 10: 6623–6635. DOI: 10.1002/ece3.6394
- Darwin Núñez, pers. comm.
- Van der Hoek Y (2018) First description of swimming behaviour of Amphisbaena bassleri L. 1758 (Squamata, Amphisbaenidae). Herpetology Notes 11: 817–818.
- Silva Haad JJ (1994) Los Micrurus de la Amazonia Colombiana. Biología y toxicología experimental de sus venenos. Colombia Amazónica 7: 1–76.
- 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.
- Riley J, Winch JM, Stimson AF, Pope RD (1986) The association of Amphisbaena alba (Reptilia: Amphisbaenia) with the leaf-cutting ant Atta cephalotes in Trinidad. Journal of Natural History 20: 459–470.
- 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 bassleri in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.
| Country | Province | Locality | Source |
| Colombia | Caquetá | El Paujil | iNaturalist |
| Colombia | Caquetá | La Esmeralda | Photo by Ana Castillo |
| Colombia | Caquetá | Puente Los Lagos | iNaturalist; photo examined |
| Colombia | Putumayo | Barrio Villa Rosa | iNaturalist; photo examined |
| Colombia | Putumayo | La Tagua | IAvH-R-1594; Borja-Acosta & Galeano Muñoz (2023) |
| Colombia | Putumayo | Vereda Santa Maria Medio | IAvH-R-9278; Borja-Acosta & Galeano Muñoz (2023) |
| Ecuador | Morona Santiago | Bomboiza | KU 147190; VertNet |
| Ecuador | Morona Santiago | Chiviaza | Reptiles of Ecuador database |
| Ecuador | Morona Santiago | El Padmi | Reptiles of Ecuador database |
| Ecuador | Morona Santiago | Gualaquiza | Online multimedia |
| Ecuador | Morona Santiago | Limón | USNM 196931; VertNet |
| Ecuador | Morona Santiago | Macuma | iNaturalist; photo examined |
| Ecuador | Morona Santiago | San Karlos | Peñafiel 2013 |
| Ecuador | Morona Santiago | Santiago de Mendez | MZUA.RE.58; examined |
| Ecuador | Morona Santiago | Sucúa | iNaturalist; photo examined |
| Ecuador | Morona Santiago | Turula | Vanzolini 2002 |
| Ecuador | Morona Santiago | Wisui | Chaparro et al. 2011 |
| Ecuador | Napo | Ávila | Vanzolini 2002 |
| Ecuador | Napo | Finca Fischer | TCWC 69771; VertNet |
| Ecuador | Napo | Ikiam | Reptiles of Ecuador database |
| Ecuador | Napo | Pimpilala | iNaturalist; photo examined |
| Ecuador | Napo | Puerto Napo | USNM 196920; VertNet |
| Ecuador | Napo | Tena | iNaturalist; photo examined |
| Ecuador | Napo | Wildsumaco Lodge | Photo by Charlie Vogt |
| Ecuador | Orellana | El Coca | QCAZ 546; Torres-Carvajal et al. 2019 |
| Ecuador | Orellana | La Joya de los Sachas | QCAZ R270; Torres-Carvajal et al. 2019 |
| Ecuador | Orellana | Loreto | Vanzolini 2002 |
| Ecuador | Orellana | Margen Norte del Río Yasuní | QCAZ 3963; Torres-Carvajal et al. 2019 |
| Ecuador | Orellana | Río Bigal | García et al. 2021 |
| Ecuador | Orellana | Rio Pucuno | USNM196913 |
| Ecuador | Orellana | Tiputini Biodiversity Station | Cisneros-Heredia 2003 |
| Ecuador | Orellana | Yasuni Scientific Station | Reptiles of Ecuador database |
| Ecuador | Pastaza | Alto Curaray | USNM 196917; VertNet |
| Ecuador | Pastaza | Arajuno | USNM 196932; VertNet |
| Ecuador | Pastaza | Bioparque Yanacocha | Photo by Andreas Kay |
| Ecuador | Pastaza | Canelos | Vanzolini 2002 |
| Ecuador | Pastaza | Copataza (Achuar) | Peñafiel 2013 |
| Ecuador | Pastaza | Intersección Cueva de los Tayos | Peñafiel 2013 |
| Ecuador | Pastaza | Kawa | Peñafiel 2013 |
| Ecuador | Pastaza | Montalvo | USNM 196916; VertNet |
| Ecuador | Pastaza | Oglán Alto | USNM 196919; VertNet |
| Ecuador | Pastaza | Puyo | iNaturalist; photo examined |
| Ecuador | Pastaza | Reserva Tamandúa | Photo by Andreas Kay |
| Ecuador | Pastaza | Río Corrientes | USNM 196914; VertNet |
| Ecuador | Pastaza | Río Pastaza | Vanzolini 2002 |
| Ecuador | Pastaza | Río Piatúa | Online multimedia |
| Ecuador | Pastaza | Sarayacu | USNM 196918; VertNet |
| Ecuador | Pastaza | Veracruz | USNM 196927; VertNet |
| Ecuador | Sucumbíos | Comunidad Sani Isla | iNaturalist; photo examined |
| Ecuador | Sucumbíos | Estación PUCE Cuyabeno | Vitt & de la Torre 1996 |
| Ecuador | Sucumbíos | Lago Agrio | Duellman 1978 |
| Ecuador | Sucumbíos | Limon Cocha | MCZ 96048; VertNet |
| Ecuador | Sucumbíos | Lumbaqui | iNaturalist |
| Ecuador | Sucumbíos | Napo Wildlife Center | Reptiles of Ecuador database |
| Ecuador | Sucumbíos | Río Cuyabeno | iNaturalist; photo examined |
| Ecuador | Sucumbíos | San Pedro de los Cofanes | iNaturalist; photo examined |
| Ecuador | Sucumbíos | Sani Lodge | Photographic record; this work |
| Ecuador | Sucumbíos | Santa Cecilia | Duellman 1978 |
| Ecuador | Zamora Chinchipe | Copalinga | Reeves et al. |
| Ecuador | Zamora Chinchipe | El Pangui | iNaturalist; photo examined |
| Ecuador | Zamora Chinchipe | El Pangui, 2 km SW of | iNaturalist; photo examined |
| Ecuador | Zamora Chinchipe | Guayzimi | iNaturalist; photo examined |
| Ecuador | Zamora Chinchipe | Loja, 50 km E of | Vanzolini 2002 |
| Ecuador | Zamora Chinchipe | Los Encuentros, 2 km NE of | iNaturalist; photo examined |
| Ecuador | Zamora Chinchipe | Zamora | Darwin Núñez, pers. comm. |
| Perú | Amazonas | Boca del Santiago | Vanzolini 2002 |
| Perú | Amazonas | Río Cenepa | Vanzolini 2002 |
| Perú | Loreto | Cashiboya | Vanzolini 2002 |
| Perú | Loreto | Contamana | Vanzolini 2002 |
| Perú | Loreto | Iquitos | Vanzolini 2002 |
| Perú | Loreto | Pampa Hermosa | Vanzolini 2002 |
| Perú | Loreto | Reforma | Vanzolini 2002 |
| Perú | Loreto | Rio Cushabatay | Vanzolini 2002 |
| Perú | Loreto | Roaboya | Vanzolini 2002 |
| Perú | Ucayali | Colonia Calleria | CAS 93931; VertNet |
| Perú | Ucayali | Pucallpa | Vanzolini 2002 |
| Perú | Ucayali | Pucalpe | MCZ 45784; VertNet |