Published December 5, 2021. Updated February 8, 2024. Open access. Peer-reviewed.

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Elegant Eyed-Lizard (Cercosaura argulus)

Reptiles of Ecuador | Sauria | Gymnophthalmidae | Cercosaura argulus

English common name: Elegant Eyed-Lizard.

Spanish common names: Lagartija colilarga elegante, lagartija rayada brillante.

Recognition: ♂♂ 14.6 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=4.8 cm. ♀♀ 14 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=4.1 cm..1,2 Species in the genus Cercosaura differ from other similar-sized leaf-litter lizards (particularly those in the genera Anadia, Alopoglossus, Arthrosaura, and Loxopholis) by having keeled and imbricate dorsal scales arranged in rows and scales on flanks smaller than dorsals.1,3 Cercosaura argulus is often confused with C. oshaughnessyi, from which it differs by having scales on flanks moderately (rather than distinctly) smaller than dorsals and arranged in 4–7 (rather than 8–12) rows.15 The absence of a femoral pore in the preanal position and rows of femoral pores separated medially by four (instead of two) ventral scales further separate C. argulus from C. oshaughnessyi.1,5 Cercosaura argulus differs from C. manicata by having brown to reddish flanks with black ocelli and two frontonasal scales (uniform dark brown flanks and a single undivided frontonasal scale in C. manicata).17 Males of C. argulus differ from females by being more brightly colored, with striking red flanks and well-defined ocelli (Fig. 1), and having 12–20 (instead of 2–6) femoral pores.1,6,7

Figure showing variation among individuals of Cercosaura argulus

Figure 1: Individuals of Cercosaura argulus from Líbano () and Ibagué (), Tolima department, Colombia.

Natural history: Cercosaura argulus is a rare species, about nine times less likely to be seen than C. oshaughnessyi in areas where both lizards co-occur. This species inhabits old growth to moderately disturbed rainforests, which may be terra-firme,8 seasonally flooded,1 or dominated by swamps.9 It also occurs in clearings,10 pastures with scattered trees,11 banana groves,10 rural gardens12 and inside houses.13 Elegant Eyed-Lizards are semi-arboreal and less terrestrial than C. oshaughnessyi.14 They forage actively in shady areas,8 either in leaf-litter on the forest floor,1,15,16 or on shrubby vegetation, vines,8 logs, and tree trunks up to about 10 m above the ground1,9,16 and probably all the way up to the canopy. Individuals have also be seen crossing dirt roads.1 These lizards are active during sunny and cloudy conditions.14 At night, they sleep in leaf-litter,11,16 under piles of debris,11 or perched on leaves.17 The diet of C. argulus is composed primarily of insect larvae and roaches.14 It also includes at least 13 other prey item categories, from spiders8 and ants to mollusks and millepedes.14 Members of this species may host nematodes as internal parasites.18,19 One female collected in Peru had two oviductal eggs,8 but the real clutch size is not known.

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..10,20,21 Cercosaura argulus is included in this category primarily because the species has a wide distribution.22 Although rare, the scarcity of records is believed to be an object of sampling caused by the species’ arboreal habits.10,16 In Brazil, about 50% of the occurrence area of C. argulus is within protected areas and about 87% of its habitat is still forested.22 In Ecuador,23 these figures are closer to 23% and 89%, respectively.

Distribution: Cercosaura argulus is native to an estimated 1,926,782 km2 area throughout the Amazon basin in Brazil, Colombia, Ecuador (Fig. 2), Guyana, Peru, and Suriname. The species also occurs west of the Andes in the drainages of the rivers Magadalena and Cauca, Colombia.

Distribution of Cercosaura argulus in Ecuador

Figure 2: Distribution of Cercosaura argulus in Ecuador. The type locality is around Santa Fe de Bogotá, Colombia. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Cercosaura, which comes from the Greek words kerkos (=tail) and saura (=lizard),24 probably refers to the long tail.25 The specific epithet argulus is a diminutive of the Greek word argos (=bright).24 It refers to the clear ocelli along the flanks.26

See it in the wild: Cercosaura argulus is a rare species that cannot be expected to be seen reliably in Ecuador, especially given its arboreal habits. Most recent observations in this country come from Yasuní National Park. Probably the best way to find lizards of this species is by scanning arboreal vegetation in well-preserved rainforest during sunny days, although some individuals have been taken using pitfall traps in Brazil.27

Authors: Amanda QuezadaaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: Laboratorio de Herpetología, Universidad del Azuay, Cuenca, Ecuador. and Alejandro ArteagacAffiliation: Khamai Foundation, Quito, Ecuador.

Academic reviewer: Jeffrey D CamperdAffiliation: Department of Biology, Francis Marion University, Florence, USA.

Photographer: Jose Vieira,eAffiliation: Tropical Herping (TH), Quito, Ecuador.,fAffiliation: ExSitu, Quito, Ecuador.

How to cite? Quezada A, Arteaga A (2024) Elegant Eyed-Lizard (Cercosaura argulus). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/RVQF3096

Literature cited:

  1. Avila-Pires TCS (1995) Lizards of Brazilian Amazonia (Reptilia: Squamata). Zoologische Verhandelingen 299: 1–706.
  2. Hoogmoed MS (1973) Notes on the herpetofauna of Surinam. IV. The lizards and amphisbaenians of Surinam. Biogeographica 4: 1–419.
  3. Doan TM (2003) A new phylogenetic classification for the gymnophthalmid genera Cercosaura, Pantodactylus, and Prionodactylus (Reptilia: Squamata). Zoological Journal of the Linnean Society 137: 101–115. DOI: 10.1046/j.1096-3642.2003.00043.x
  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. Torres-Carvajal O, Lobos SE, Venegas PJ (2015) Phylogeny of Neotropical Cercosaura (Squamata: Gymnophthalmidae) lizards. Molecular Phylogenetics and Evolution 93: 281–288. DOI: 10.1016/j.ympev.2015.07.025
  6. 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.
  7. Uzzell T (1973) A revision of the genus Prionodactylus with a new genus for P. leucostictus and notes on the genus Euspondylus (Sauria, Teiidae). Postilla 159: 1–67.
  8. Duellman WE (2005) Cusco amazónico: the lives of amphibians and reptiles in an Amazonian rainforest. Cornell University Press, Ithaca, 433 pp.
  9. Moravec J, Aparicio J (2004) Notes on the herpetofauna of Nacebe (Provincia Abuna, Departamento Pando, Bolivia). Journal of the National Museum (Prague), Natural History Series 173: 1–28.
  10. Caicedo JR, Rivas G, Gutiérrez-Cárdenas P, Perez P, Moravec J, Aparicio J, Avila-Pires TCS (2019) Cercosaura argulus. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2019-2.RLTS.T178355A44953641.en
  11. Jose Vieira, field observation.
  12. Photo by Juan Pablo Montoya.
  13. Photo by Cristina Restrepo.
  14. Vitt LJ, Avila-Pires TCS, Zani PA, Espósito MC, Sartorius SS (2003) Life at the interface: ecology of Prionodactylus oshaughnessyi in the western Amazon and comparisons with P. argulus and P. eigenmanni. Canadian Journal of Zoology 81: 302–312. DOI: 10.1139/z03-004
  15. Photo by Tom Kirschey.
  16. Doan TM, Neff SE, Adams AL, Ruiz S, Valentine KE (2012) Cercosaura argulus (Elegant Eyed Lizard): arboreal behavior. Herpetological Review 42: 599–600.
  17. Photo by Morley Read.
  18. Ávila RW, Silva RJ (2010) Checklist of helminths from lizards and amphisbaenians (Reptilia, Squamata) of South America. Journal of Venomous Animals and Toxins Including Tropical Diseases 16: 543–572. DOI: 10.1590/S1678-91992010000400005
  19. McAllister CT, Bursey CR, Freed PS (2010) Helminth parasites of amphibians and reptiles from the Ucayali region, Peru. Journal of Parasitology 96: 444–447. DOI: 10.1645/ge-2206.1
  20. 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.
  21. 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.
  22. Ribeiro-Júnior MA, Amaral S (2016) Diversity, distribution, and conservation of lizards (Reptilia: Squamata) in the Brazilian Amazonia. Neotropical Biodiversity 2: 195–421. DOI: 10.1080/23766808.2016.1236769
  23. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  24. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.
  25. Wagler JG (1830) Natürliches System der Amphibien: mit vorangehender Classification der Säugetiere und Vögel: ein Beitrag zur vergleichenden Zoologie. J.G. Cotta'scchen, München, 354 pp. DOI: 10.5962/bhl.title.58730
  26. Sturaro MJ, Avila-Pires TCS, Rodrigues MT (2017) Molecular phylogenetic diversity in the widespread lizard Cercosaura ocellata (Reptilia: Gymnophthalmidae) in South America. Systematics and Biodiversity 15: 532–540. DOI: 10.1080/14772000.2017.1284913
  27. de Freitas MA, Oliveira e Sousa S, Saldanha Vieira R, Farias T, Barbosa de Moura GJ (2013) First record of Cercosaura argulus (Peters, 1863) (Squamata: Gymnophthalmidae) for the state of Maranhão, Brazil. Check List 9: 1541–1542. DOI: 10.15560/9.6.1541

Appendix 1: Locality data used to create the distribution map of Cercosaura argulus in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

EcuadorMorona SantiagoQuebrada PampantsTorres-Carvajal et al. 2019
EcuadorNapoLago Agrio Avila-Pires 1995
EcuadorNapoSan Jose Viejo de SumacoAvila-Pires 1995
EcuadorOrellanaCampo SPFTorres-Carvajal et al. 2015
EcuadorOrellanaPompeya–Iro road, km 49Torres-Carvajal et al. 2015
EcuadorOrellanaSan José de PayaminoMaynard et al. 2017
EcuadorOrellanaTiputini Biodiversity StationCisneros-Heredia 2003
EcuadorOrellanaYarina LodgeThis work
EcuadorPastazaRío CapahuariAvila-Pires 1995
EcuadorSucumbíosLago Agrio iNaturalist
EcuadorSucumbíosLimoncocha Biological ReserveiNaturalist
EcuadorSucumbíosPuerto LibreAvila-Pires 1995
EcuadorSucumbíosSacha LodgeiNaturalist
PeruAmazonasCaterpizaAvila-Pires 1995
PeruAmazonasHuampamiAvila-Pires 1995
PeruAmazonasKayamasAvila-Pires 1995
PeruAmazonasSan Antonio, Río CenepaAvila-Pires 1995
PeruAmazonasShiringaAvila-Pires 1995