Published February 10, 2023. Open access.

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Geoffroy’s Side-necked Turtle (Phrynops geoffroanus)

Reptiles of Ecuador | Testudines | Chelidae | Phrynops geoffroanus

English common names: Geoffroy’s Side-necked Turtle, Geoffroy’s Toadhead Turtle.

Spanish common names: Tortuga barbicha, tortuga cabeza de sapo de Geoffroy (Ecuador); teparo, tortuga de arroyo misionera (Colombia).

Recognition: ♂♂ 39.5 cmMaximum straight length of the carapace. ♀♀ 46.3 cmMaximum straight length of the carapace..1 The Geoffroy’s Side-necked Turtle (Phrynops geoffroanus) can be distinguished from other aquatic turtles in the Ecuadorian Amazon by having a small and narrow olive gray head with a black postocular stripe (Fig. 1) and alternating black and white stripes on the throat.2,3 Unlike other Ecuadorian side-necked turtles, the carapace in P. geoffroanus is flattened, flared peripherally, with a central keel, and is dark brown or blackish in coloration.2 The first vertebral scute is wider than long and the cervical scute is long and narrow.3 The feet are fully webbed, with five claws on the forelimbs and four on the hindlimbs.2 Males are smaller than females and have a longer, thicker tail.2,3

Figure showing variation among individuals of Phrynops geoffroanus

Figure 1: Individuals of Phrynops geoffroanus from Bolívar State, Venezuela (); and Parque Ecológico de Nueva Loja, Sucumbíos province, Ecuador (). ad=adult, sa=subadult, j=juvenile.

Natural history: Phrynops geoffroanus is a rarelyTotal average number of reported observations per locality less than ten. seen chelonian in Ecuador, but is locally common in Brazil, where population densities of 170–230 individuals/hectare have been reported.4 Turtles of this species are diurnal and strictly aquatic, remaining most of the time submerged close to the surface and rarely wandering on dry land.25 However, females are more terrestrial than males, probably due to nesting incursions.5 Geoffroy’s Toadhead Turtles live in rivers, streams, lagoons, marshes, and lakes within old-growth closed canopy forests having abundant margin vegetation, although they also occur in polluted rivers in the periphery of cities.2,6,7 They like to sunbathe during the hottest hours of the day on inclined trunks that project over the water, where groups of up to 20 individuals may be seen together.2 At night, they sleep on submerged trunks near the surface.2 Given their stream-dwelling habits, the home range in P. geoffroanus is usually linear. In females, it is 330 m; in males is 180 m.5

In dry and humid climates, the diet of Phrynops geoffroanus is carnivorous, including fish, insects, arthropods, mollusks, and carrion; during the rainy season, it becomes facultatively frugivorous, feeding on fruits.2,4 Geoffroy’s Side-necked Turtle are not aggressive, so they don’t try to bite when handled.2 However, they have secretory glands that release a strong musk when captured.6 There are records of individuals having missing segments of the limbs due to piranha bites.2 Lizards of the genus Tupinambis are the most important natural predators of the eggs of P. geoffroanus.8,9 Reproductive activity in P. geoffroanus begins when males reach 20 cm in straight carapace length; 24.1 cm in females.10 Reproduction takes place during or at the beginning of the dry season and mating occurs in the water.10 At dusk, females make shallow nests in the sand or in clay soil besides the water, where they deposit 7–20 eggs.7,9 These are spherical with a brittle shell and an average length of 29–35 mm, a diameter of 30 mm, and a weight of 14–23 g.9 The incubation period is 149–331 days (about 5–11 months).10

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..11 Phrynops geoffroanus is listed in this category given its wide distribution over areas that have not been heavily affected by deforestation. Furthermore, this is one of the few Amazonian turtle species not widely consumed because it is tabooed and believed to cause allergic reactions.12 Also, some indigenous groups in Colombia consider them to be sacred and refrain from consuming their meat. Finally, individuals of P. geoffroanus adapt rapidly to polluted rivers.4 However, nest predation by lizards, the creation of hydroelectric projects, and intense habitat fragmentation and destruction are affecting some populations of P. geoffroanus.8,9

Distribution: Phrynops geoffroanus is native to an estimated area of 4,156,787 km2 throughout much of tropical South America, including the Amazon basin.1 In Ecuador, the species is known from nine localities at elevations between 149 and 437 m (Fig. 2).

Distribution of Phrynops geoffroanus in Ecuador

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

Etymology: The generic name Phrynops, which comes from the Greek words phryne (meaning “toad”) and ops (meaning “appearance”),13 refers to the head morphology of this turtle. The specific epithet geoffroanus honors Etienne Geoffroy Saint-Hilaire, a French zoologist. Two of his most important works were establishing the principle of “unity of composition” and writing Cours de l’Histoire Naturelle des Mammifères.14

See it in the wild: Geoffroy’s Side-necked Turtles are considered rare throughout Ecuador. Only one locality, Tiputini Biodiversity Station, has more than one record. In this reserve, individuals were observed during mornings and afternoons, basking over logs partially submerged at the mouth of a small affluent of the Tiputini River, and along the river itself.6

Authors: Gabriela SandovalaAffiliation: Pontificia Universidad Católica del Ecuador, Quito, Ecuador. and Alejandro ArteagabAffiliation: Khamai Foundation, Quito, Ecuador.

Photographer: Jose VieiracAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador.

How to cite? Sandoval G, Arteaga A (2023) Geoffroy’s Side-necked Turtle (Phrynops geoffroanus). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/KAKS4869

Literature cited:

  1. Rhodin AGJ, Iverson JB, Bour R, Fritz U, Georges A, Shaffer HB, van Dijk PP (2021) Turtles of the world: annotated checklist and atlas of taxonomy, synonymy, distribution, and conservation status. Chelonian Research Monographs 8: 1–472. DOI: 10.3854/crm.8.checklist.atlas.v9.2021
  2. Rueda-Almonacid JV, Carr JL, Mittermeier RA, Rodríguez-Mahecha JV, Mast RB, Vogt RC, Rhodin AGJ, de la Ossa-Velásquez J, Rueda JN, Mittermeier CG (2007) Las tortugas y los cocodrilianos de los países andinos del trópico. Conservación Internacional, Bogotá, 538 pp.
  3. Morales-Betancourt MA, Lasso CA, Páez VP (2012) Phrynops geoffroanus. In: Páez VP, Morales-Betancourt MA, Lasso CA, Castaño-Mora OV, Bock BC (Eds). Biología y conservación de las tortugas continentales de Colombia. Serie Editorial Recursos Hidrobiológicos y Pesqueros Continentales de Colombia, Instituto de Investigación de Recursos Biológicos Alexander von Humboldt (IAvH), Bogotá, 266–268.
  4. Souza FL, Abe AS (2000) Feeding ecology, density and biomass of the freshwater turtle, Phrynops geoffroanus, inhabiting a polluted urban river in south-eastern Brazil. Journal of Zoology 252: 437–446. DOI: 10.1111/j.1469-7998.2000.tb01226.x
  5. Pinheiro Müller MM, Ortega Z, Antunes PC, Lopes Seino L, Hammarstron MJ, França Balbino-Silva AC, Rodrigues Oliveira-Santos LG (2019) The home range of adult Phrynops geoffroanus (Testudines, Chelidae) in relation to sex and body mass. Herpetozoa 32: 259–265. DOI: 10.3897/herpetozoa.32.e38237
  6. Cisneros-Heredia DF (2006) Turtles of the Tiputini Biodiversity Station with remarks on the diversity and distribution of the Testudines from Ecuador. Biota Neotropica 6: 1–16. DOI: 10.1590/S1676-06032006000100011
  7. Souza FL, Abe AS (2001) Population structure and reproductive aspects of the freshwater turtle, Phrynops geoffroanus, inhabiting an urban river in Southeastern Brazil. Studies on Neotropical Fauna and Environment 36: 57–62. DOI: 10.1076/snfe.
  8. Vogt RC (2008) Tartarugas da Amazônia. Instituto Nacional de Pesquisa da Amazônia, Lima, 104 pp.
  9. Schneider L, Ferrara CR, Vogt RC, Guilhon AV (2011) Nesting ecology and nest predation of Phrynops geoffroanus (Testudines, Chelidae) in the Guaporé River of the Brazilian and Bolivian Amazon. Chelonian Conservation and Biology 10: 206–212. DOI: 10.2744/1071-8443-10.2.206
  10. Molina FB (1991) Some observations on the biology and behavior of Phrynops geoffroanus (Schweigger, 1812) in captivity (Reptilia, Testudines, Chelidae). Grupo de Estudos Ecologicos 3: 35–37.
  11. Morales-Betancourt MA, Lasso CA, Páez VP, Bock BC (2005) Libro rojo de reptiles de Colombia. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá, 257 pp.
  12. Ferronato BO, Cruzado G (2013) Uses, beliefs, and conservation of turtles by Ashaninka indigenous people, Central Peru. Chelonian Conservation and Biology 12: 308–313. DOI: 10.2744/CCB-1025.1
  13. Beolens B, Watkins M, Grayson M (2011) The eponym dictionary of reptiles. Johns Hopkins University Press, Baltimore, 296 pp.
  14. Panchen AL (2001) Etienne Geoffroy St.-Hilaire: father of “evo-devo.” Evolution and Development 3: 41–46. DOI: 10.1046/j.1525-142x.2001.01085.x

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

ColombiaCaquetáEl CaféMap 22 in Ferrara et al. 2017
ColombiaCaquetáFlorenciaMCZ 53280; VertNet
ColombiaCaquetáÑaseraMNHN 2008.306; VertNet
ColombiaCaquetáParte Alta del Río MesayIAvH-R-4834; Borja-Acosta & Galeano Muñoz 2023
ColombiaCaquetáRío Caquetá entre los ríos Caguán y CuemaniICN 7776; Calderón et al. 2022
ColombiaCaquetáRío Caquetá junto a la isla La ViejaICN 7777; Calderón et al. 2022
ColombiaCaquetáRío SunciyaMap 22 in Ferrara et al. 2017
ColombiaCaquetáSolanoMap 22 in Ferrara et al. 2017
ColombiaCaquetáTangoMap 22 in Ferrara et al. 2017
ColombiaPutumayoPuerto BoyMap 22 in Ferrara et al. 2017
EcuadorNapoRío CotopinoOrcés 1949
EcuadorNapoRío PucunoOrcés 1949
EcuadorOrellanaMouth of the Río SunoMCZ 68854; VertNet
EcuadorOrellanaTiputini Biodiversity StationCisneros-Heredia 2006
EcuadorSucumbíosLagartocochaMap 22 in Ferrara et al. 2017
EcuadorSucumbíosParque Ecológico Nueva LojaThis work; Fig. 1
EcuadorSucumbíosPuerto El CarmenMap 22 in Ferrara et al. 2017
EcuadorSucumbíosPuerto OreDuellman 1978
EcuadorSucumbíosSanta CeciliaDuellman 1978