Published October 11, 2020. Updated December 1, 2023. Open access. Peer-reviewed. | Purchase book ❯ |
Unicolored Lightbulb-Lizard (Riama unicolor)
Reptiles of Ecuador | Sauria | Gymnophthalmidae | Riama unicolor
English common names: Unicolored Lightbulb-Lizard, Drab Lightbulb-Lizard.
Spanish common names: Lagartija minadora de vientre rojo.
Recognition: ♂♂ 14.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.8 cm. ♀♀ 14.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.5 cm..1,2 Lightbulb-lizards are easily distinguishable from other lizards by their fossorial habits and extremities so short that the front and hind limbs cannot reach each other.1 Unicolored Lightbulb-Lizards differ from other members of the genus by having a reddish tail underside adorned with black longitudinal lines (Fig. 1). In contrast, other lightbulb lizard species potentially coexisting with R. unicolor, namely R. colomaromani, R. simotera, and R. raneyi, exhibit entirely black ventral surfaces.1 Adult males of R. unicolor can be differentiated from females by their broader heads and more vibrant lower flanks.
Figure 1: Individuals of Riama unicolor from Ecuador: La Libertad, Carchi province (); Tabacundo, Pichincha province (). j=juvenile.
Natural history: Riama unicolor is a locally common fossorial lizard that inhabits old-growth to heavily disturbed montane forests and highland shrublands. The species also occupies areas containing a mixture of pastures, crops, and remnants of native vegetation, and surprisingly, even gardens within densely populated urban zones.2,3 Lizards of this species predominantly reside in tunnels they excavate in soft soil or beneath rocks, logs, debris, and flowerpots.1,2 On rare occasions, they have been observed crossing roads during broad daylight.2 In captivity, individuals consume maggots and small insects.1 When threatened, Unicolored Lightbulb-Lizards flee into crevices. If captured, they may bite or readily shed the tail. These lizards are particularly vulnerable to high temperatures, succumbing to the sun or even brief handling for just a few seconds.1 There are records of frogs (Gastrotheca riobambae) preying upon individuals of R. unicolor.1
Conservation: Vulnerable Considered to be facing a high risk of extinction in the mid-term future..4 Riama unicolor is listed in this category because the species has a relatively small (~6,682 km2) extent of occurrence, its habitat is severely fragmented, and it has undergone widespread observed population declines.4 An estimated 64.3% of the habitat of R. unicolor has already been destroyed5 by encroaching human activities such as urban development, agriculture, cattle grazing, and the replacement of native vegetation with eucalyptus and pine trees.2,4 Fortunately, the species persist in urban areas despite a considerable degree of habitat modification,3 being one of the few reptiles able to survive in Ecuador’s capital city.3
Distribution: Riama unicolor is endemic to an area of approximately 6,682 km2 in the inter-Andean valleys of northern Ecuador (Fig. 2).
Figure 2: Distribution of Riama unicolor in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.
Etymology: The generic name Riama does not appear to be a reference to any feature of this group of lizards, but a matter of personal taste. John Edward Gray usually selected girls’ names to use on reptiles.6–9 The specific epithet unicolor is a Latin adjective that probably refers to the nearly unicolored dorsal pattern.1
See it in the wild: Unicolored Lightbulb-Lizards are recorded rarely unless actively searched for by digging in areas of soft soil or by turning over rocks and logs in suitable habitats. Prime locations for encountering the species include Refugio Pasochoa and Reserve Pulhulahua.
Special thanks to Walter Jennings for symbolically adopting the Unicolored Lightbulb-Lizard and helping bring the Reptiles of Ecuador book project to life.
Click here to adopt a species.
Acknowledgments: Special thanks to Amanda Quezada, Frank Pichardo, Harry Turner, and Jorge Castillo for their help and companionship during the search of specimens of Riama unicolor in the field. Thanks to Diego Piñán and María Jose Quiroz for providing locality data of R. unicolor. Thanks to Andres Pérez for the post-processing of images. This account was published with the support of Secretaría Nacional de Educación Superior Ciencia y Tecnología (programa INEDITA; project: Respuestas a la crisis de biodiversidad: la descripción de especies como herramienta de conservación; No 00110378), Programa de las Naciones Unidas (PNUD), and Universidad San Francisco de Quito (USFQ).
Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.
Academic reviewer: Jeffrey D CamperbAffiliation: Department of Biology, Francis Marion University, Florence, USA.
Photographers: Jose VieiracAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador. and Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.
How to cite? Arteaga A (2023) Unicolored Lightbulb-Lizard (Riama unicolor). 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/PEFN1380
Literature cited:
- Kizirian DA (1996) A review of Ecuadorian Proctoporus (Squamata: Gymnophthalmidae) with descriptions of nine new species. Herpetological Monographs 10: 85–155. DOI: 10.2307/1466981
- Field notes, Reptiles of Ecuador book project.
- Arteaga A, Bustamante L, Guayasamin JM (2013) The amphibians and reptiles of Mindo. Universidad Tecnológica Indoamérica, Quito, 257 pp.
- Cisneros-Heredia DF, Brito J, Yánez-Muñoz M, Almendáriz A (2019) Riama unicolor. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2019-3.RLTS.T50950566A50950573.en
- MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
- Gray JE (1831) Description of a new genus of ophisaurean animal, discovered by the late James Hunter in New Holland. Treuttel, Würtz & Co., London, 40 pp.
- Gray JE (1831) A synopsis of the species of the class Reptilia. In: Griffith E, Pidgeon E (Eds) The animal kingdom arranged in conformity with its organization. Whittaker, Treacher, & Co., London, 1–110.
- Gray JE (1838) Catalogue of the slender-tongued saurians, with descriptions of many new genera and species. Annals and Magazine of Natural History 1: 274–283.
- Gray JE (1845) Catalogue of the specimens of lizards in the collection of the British Museum. Trustees of the British Museum, London, 289 pp.
Appendix 1: Locality data used to create the distribution map of Riama unicolor in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.
| Country | Province | Locality | Source |
| Ecuador | Carchi | Gruta de la Paz | Galarza-Verkovitch 2020 |
| Ecuador | Carchi | Huaca | Aguirre et al. 2014 |
| Ecuador | Carchi | La Libertad | This work; Fig. 1 |
| Ecuador | Carchi | Montúfar | Kizirian 1996 |
| Ecuador | Carchi | Montúfar–Atal | Sánchez-Pacheco et al. 2012 |
| Ecuador | Carchi | San Gabriel | Reptiles of Ecuador book database |
| Ecuador | Carchi | San Gabriel–El Angel | Reptiles of Ecuador book database |
| Ecuador | Carchi | Tulcán | Reptiles of Ecuador book database |
| Ecuador | Carchi | Tulcán, 14 km W of | Photo by Luis Coloma |
| Ecuador | Carchi | Vicinities of La Libertad | Reptiles of Ecuador book database |
| Ecuador | Imbabura | Cahuasquí–Urcuquí | Photo by Diego Piñán |
| Ecuador | Imbabura | Chachimbiro | Kizirian 1996 |
| Ecuador | Imbabura | Cotacachi–Intag 1 | Aguirre et al. 2014 |
| Ecuador | Imbabura | Cotacachi–Intag 2 | Aguirre et al. 2014 |
| Ecuador | Imbabura | Cuicocha | Kizirian 1996 |
| Ecuador | Imbabura | Hacienda Zuleta | Photo by Anton Sorokin |
| Ecuador | Imbabura | Imbabura-Mariano Acosta | Reptiles of Ecuador book database |
| Ecuador | Imbabura | Islote Yerovi | Almendáriz & Orcés 2004 |
| Ecuador | Imbabura | Otavalo, 8 km NW of | Kizirian 1996 |
| Ecuador | Imbabura | Perihuela | Reptiles of Ecuador book database |
| Ecuador | Imbabura | Pimampiro | Kizirian 1996 |
| Ecuador | Imbabura | Quiroga, 7 km W of | Kizirian 1996 |
| Ecuador | Imbabura | San Pablo | Kizirian 1996 |
| Ecuador | Imbabura | San Rafael, 3 km SE of | Doan 2003 |
| Ecuador | Imbabura | Sigsipamba | iNaturalist; photo examined |
| Ecuador | Imbabura | Tabacundo–Mojanda | KU 221766; VertNet |
| Ecuador | Imbabura | Tumbabiro | Aguirre et al. 2014 |
| Ecuador | Imbabura | Urcusiqui | Kizirian 1996 |
| Ecuador | Imbabura | Vía Cotacachi–Quiroga | iNaturalist; photo examined |
| Ecuador | Imbabura | Yaguachi | Galarza-Verkovitch 2020 |
| Ecuador | Pichincha | Aloguincho | Galarza-Verkovitch 2020 |
| Ecuador | Pichincha | Between Quito and Papallacta | Kizirian 1996 |
| Ecuador | Pichincha | Bosque de Pasochoa | Field notes of Felipe Campos |
| Ecuador | Pichincha | Brazil y Zamora | Photo by Viviana Jaramillo |
| Ecuador | Pichincha | Calacalí | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Cayambe | Kizirian 1996 |
| Ecuador | Pichincha | Cayambe, 10 km N of | Kizirian 1996 |
| Ecuador | Pichincha | Chillogallo | Kizirian 1996 |
| Ecuador | Pichincha | Colegio Fernandez Madrid | iNaturalist; photo examined |
| Ecuador | Pichincha | El Inca | iNaturalist; photo examined |
| Ecuador | Pichincha | Hacienda Gorzon | Kizirian 1996 |
| Ecuador | Pichincha | Hacienda Olalla | Kizirian 1996 |
| Ecuador | Pichincha | Hacienda Pesillo | Almendáriz & Orcés 2004 |
| Ecuador | Pichincha | La Josefina | iNaturalist; photo examined |
| Ecuador | Pichincha | La Playita | iNaturalist; photo examined |
| Ecuador | Pichincha | La Unión | iNaturalist; photo examined |
| Ecuador | Pichincha | Machachi | Sánchez-Pacheco et al. 2012 |
| Ecuador | Pichincha | Mirador de Guápulo | iNaturalist; photo examined |
| Ecuador | Pichincha | Near El Crater | iNaturalist; photo examined |
| Ecuador | Pichincha | Nono | María Jose Quiroz, pers. comm. |
| Ecuador | Pichincha | Paloguillo | Field notes of Juan Freile |
| Ecuador | Pichincha | Pan-American highway at Equator | USNM 196250; VertNet |
| Ecuador | Pichincha | Parque Metropolitano | iNaturalist; photo examined |
| Ecuador | Pichincha | Parque Rumipamba | Photo by Finding Species |
| Ecuador | Pichincha | Pasochoa | Kizirian 1996 |
| Ecuador | Pichincha | Pifo, 12 km E of | Kizirian 1996 |
| Ecuador | Pichincha | PUCE | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Quito | Kizirian 1996 |
| Ecuador | Pichincha | Quito, 40 SE of | Sánchez-Pacheco et al. 2012 |
| Ecuador | Pichincha | Río Machángara | Kizirian 1996 |
| Ecuador | Pichincha | San Jorge Ecolodge | Photo by Clint King |
| Ecuador | Pichincha | SE Slopes Guagua Pichincha | Kizirian 1996 |
| Ecuador | Pichincha | Tabacundo | Kizirian 1996 |
| Ecuador | Pichincha | Tabacundo, 2.5 km W of | Kizirian 1996 |
| Ecuador | Pichincha | Tabacundo, 3.8 km W of | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Tabacundo, 5.9 km W of | Kizirian 1996 |
| Ecuador | Pichincha | Tabacundo, 7 km N of | This work; Fig. 1 |
| Ecuador | Pichincha | Valle de los Chillos | Kizirian 1996 |
| Ecuador | Pichincha | Vía a Molinuco | Galarza-Verkovitch 2020 |