Published February 2, 2024. Open access. | Gallery ❯ |
Amazonian Puffing-Snake (Phrynonax sexcarinatus)
Reptiles of Ecuador | Serpentes | Colubridae | Phrynonax sexcarinatus
English common name: Amazonian Puffing-Snake.
Spanish common name: Culebra silbadora amazónica, .
Recognition: ♂♂ 152.7 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=112.8 cm. ♀♀ 180.6 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=120 cm..1–3 Phrynonax sexcarinatus differs from other large diurnal snakes in Amazonian Ecuador by having dorsal scales arranged in 21–23 rows at mid-body, with the 3–6 median rows being feebly keeled.1–4 The iris pattern is diagnostic: mottled silvery with a dark median stripe.5 The coloration in this species changes throughout the organism’s lifespan. In juveniles, the dorsum is light brown with dark reddish brown crossbars and a contrasting postocular stripe.1,2 In adults, the dorsal coloration becomes uniformly brown (Fig. 1). This species can be confused with Spilotes sulphureus, but in the latter the dorsal scales are all strongly keeled and arranged in 19 rows at mid-body.6
Figure 1: Individuals of Phrynonax sexcarinatus: Jatun Sacha Biological Reserve, Napo province, Ecuador (); Napo Wildlife Center, Orellana province, Ecuador (); Leticia, Amazonas state, Colombia (). j=juvenile.
Natural history: Phrynonax sexcarinatus is a semi-arboreal snake that occurs in the rainforest floor as well as on shrubs and trees.3,7 These snakes are usually seen active on semi-open areas during sunny days.8 At night, they roost on shrubs 1.8–3.5 m above the ground.7 Puffing snakes are active hunters having an aglyphous dentition, meaning their teeth lack specialized grooves to deliver venom. The diet in P. sexcarinatus consists primarily on birds and their eggs,3,9 but also includes lizards and small mammals.7,10,11 Juveniles are insectivorous, feeding on beetles, moths, and grasshoppers.10 Gravid females have been found to contain 11 eggs,5 but the real clutch size is not known. Puffing snakes are known for their defense behavior. When threatened, they keep the anterior half of the body elevated in an “S” shape, while compressing it laterally and inflating the neck.8 With the mouth open, they produce a hissing sound and strike the observer.7,8
Conservation: Least Concern Believed to be safe from extinction given current circumstances..12 Phrynonax sexcarinatus is listed in this category primarily on the basis of the species’ wide distribution, presence in protected areas, and adaptability to habitat modification provided there is tree cover remaining.12 The most important threat to some populations is deforestation and habitat fragmentation caused by large-scale cattle ranching and the creation of new roads. The survival of this arboreal snake is contingent upon the availability of trees, as they serve both as protective cover against predators and as a source of forage. Lastly, Amazonian Puffing-Snakes are usually killed on sight, as they are perceived to be dangerous.
Distribution: Phrynonax sexcarinatus is widely distributed throughout the Amazon basin of Bolivia, Brazil, Colombia, Ecuador (Fig. 2), French Guiana, Guyana, Peru, Suriname, and Venezuela. The species also occurs in Trinidad Island.
Figure 2: Distribution of Phrynonax sexcarinatus in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.
Etymology: The generic name Phrynonax comes from the Greek words phryne (=toad) and anax (=king),13 and roughly translates to “master of the toads.” The specific name sexcarinatus comes from the Latin words sex (=six) and carinatus (=keeled),13 and refers to the number of keeled dorsal scale rows.
See it in the wild: Amazonian Puffing-Snakes are seen at a rate of about once every few weeks in forested localities throughout their area of distribution in Ecuador. These snakes are frequently sighted at Finca Heimatlos and Jatun Sacha Biological Reserve.
Authors: Gabriela SandovalaAffiliation: Pontificia Universidad Católica del Ecuador, Quito, Ecuador. and Alejandro ArteagabAffiliation: Khamai Foundation, Quito, Ecuador.
Photographers: Jose VieiracAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador. and Sebastián Di DoménicoeAffiliation: Keeping Nature, Bogotá, Colombia.
How to cite? Sandoval G, Arteaga A (2024) Amazonian Puffing-Snake (Phrynonax sexcarinatus). 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/YWAK9120
Literature cited:
- de Fraga R, Lima AP, da Costa Prudente AL, Magnusson WE (2013) Guia de cobras da região de Manaus - Amazônia Central. Editopa Inpa, Manaus, 303 pp.
- Lopes LV, Passos P (2023) Taxonomic status of the enigmatic Natrix sexcarinata Wagler, 1824 (Serpentes: Colubridae: Colubrinae). Zootaxa 5244: 123–144. DOI: 10.11646/zootaxa.5244.2.2
- Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
- Natera-Mumaw M, Esqueda-González LF, Castelaín-Fernández M (2015) Atlas serpientes de Venezuela. Dimacofi Negocios Avanzados S.A., Santiago de Chile, 456 pp.
- Beebe W (1946) Field notes on the snakes of Kartabo, British Guiana, and Caripito, Venezuela. Zoologica 31: 11–52.
- 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.
- Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
- Field notes, Reptiles of Ecuador book project.
- Angulo F, Chávez G (2017) First report of predation on Speckled Chachalaca (Ortalis guttata) eggs by Puffing Snake (Phrynonax polylepis) in Central Peru. Boletín UNOP 12: 27–33.
- Cisneros-Heredia DF (2005) Pseustes poecilonotus and Pseustes shropshirei (Puffing Snakes): diet. Herpetological Review 36: 326–327.
- Cunha OR, Nascimento FP (1993) Ofídios da Amazônia. As cobras da região leste do Pará. Papéis Avulsos Museu Paraense Emílio Goeldi 40: 9–87.
- Murphy J (2021) Phrynonax polylepis. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2021-3.RLTS.T64003414A64003426.en
- 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 Phrynonax sexcarinatus in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.
| Country | Province | Locality | Source |
| Colombia | Putumayo | Orito, 20 km W of | iNaturalist; photo examined |
| Colombia | Putumayo | Resguardo Indígena Huitora | Ruiz Valderrama 2023 |
| Ecuador | Morona Santiago | Logroño, 4.6 km S of | Jadin et al. 2014 |
| Ecuador | Morona Santiago | Macuma, 2.2 km E of | iNaturalist; photo examined |
| Ecuador | Morona Santiago | Macuma, 2.8 km E of | iNaturalist; photo examined |
| Ecuador | Morona Santiago | Macuma, 8.5 km N of | iNaturalist; photo examined |
| Ecuador | Morona Santiago | Puerto Morona, 8 km W of | Pazmiño-Otamendi 2020 |
| Ecuador | Morona Santiago | Sua Entza, 9 km S of | iNaturalist; photo examined |
| Ecuador | Morona Santiago | Sucúa | MZUA.Re.0047; examined |
| Ecuador | Napo | Ahuano, 3.3 km SE of | iNaturalist; photo examined |
| Ecuador | Napo | AmaZOOnico | iNaturalist; photo examined |
| Ecuador | Napo | Anaconda Lodge | Nogueira et al. 2019 |
| Ecuador | Napo | Archidona, 7.3 km E of | iNaturalist; photo examined |
| Ecuador | Napo | Huella Verde Lodge | Reptiles of Ecuador book database |
| Ecuador | Napo | Ikiam University | iNaturalist; photo examined |
| Ecuador | Napo | Jatun Sacha Biological Station | Reptiles of Ecuador book database |
| Ecuador | Napo | Misahuallí | Nogueira et al. 2019 |
| Ecuador | Napo | Puente sobre el río Uchuculin | Nogueira et al. 2019 |
| Ecuador | Napo | Río Piraña | Nogueira et al. 2019 |
| Ecuador | Napo | Yachana Reserve | Whitworth & Beirne 2011 |
| Ecuador | Orellana | 24 de Mayo | iNaturalist; photo examined |
| Ecuador | Orellana | Ávila Viejo | Nogueira et al. 2019 |
| Ecuador | Orellana | Estación PUCE, 7.8 km N of | iNaturalist; photo examined |
| Ecuador | Orellana | Loreto | Nogueira et al. 2019 |
| Ecuador | Orellana | Pozo Petrolero Amo A-2 | Nogueira et al. 2019 |
| Ecuador | Orellana | Pozo Petrolero Daimi I | Nogueira et al. 2019 |
| Ecuador | Orellana | Río Payamino | FHGO 0192; VertNet |
| Ecuador | Orellana | San José de Suno, 7.2 km SE of | iNaturalist; photo examined |
| Ecuador | Orellana | Tiputini Airport | iNaturalist; photo examined |
| Ecuador | Orellana | Tiputini Biodiversity Station | iNaturalist; photo examined |
| Ecuador | Orellana | Vía Pompeya Sur–Iro, km 46 | Nogueira et al. 2019 |
| Ecuador | Orellana | Yasuní Scientific Station | Reptiles of Ecuador book database |
| Ecuador | Pastaza | Andoas | Nogueira et al. 2019 |
| Ecuador | Pastaza | Anga Cocha | Nogueira et al. 2019 |
| Ecuador | Pastaza | Chichirota | Nogueira et al. 2019 |
| Ecuador | Pastaza | Comunidad Santa Cecilia | Reptiles of Ecuador book database |
| Ecuador | Pastaza | Diez de agosto, 3.6 km E of | USNM 204172; VertNet |
| Ecuador | Pastaza | Finca Heimatlos | iNaturalist; photo examined |
| Ecuador | Pastaza | Montalvo | Ortega-Andrade 2010 |
| Ecuador | Pastaza | Montalvo, 5 km E of | USNM 204167; VertNet |
| Ecuador | Pastaza | Moretecocha, 11 km N of | USNM 204174; VertNet |
| Ecuador | Pastaza | Río Copataza | Nogueira et al. 2019 |
| Ecuador | Pastaza | Río Cotapino | Nogueira et al. 2019 |
| Ecuador | Pastaza | Río Tigre | USNM 204170; VertNet |
| Ecuador | Pastaza | Sarayacu | Nogueira et al. 2019 |
| Ecuador | Pastaza | Sarayacu, 34 km SE of | USNM 204175; VertNet |
| Ecuador | Pastaza | Teresa Mama, 1.7 km S of | NMNH 204165; VertNet |
| Ecuador | Pastaza | Vía a Canelos | Reptiles of Ecuador book database |
| Ecuador | Pastaza | Villano | Nogueira et al. 2019 |
| Ecuador | Sucumbíos | Bosque Protector Aguarico | Nogueira et al. 2019 |
| Ecuador | Sucumbíos | El Dorado de Cascales, 7.7 km W of | iNaturalist; photo examined |
| Ecuador | Sucumbíos | Estación PUCE en Cuyabeno | Nogueira et al. 2019 |
| Ecuador | Sucumbíos | Lago Agrio | Photo by Ernesto Arbeláez |
| Ecuador | Sucumbíos | Limoncocha | LSUMZ 37929; VertNet |
| Ecuador | Sucumbíos | Lumbaqui, 1.6 km W of | UTA-R 65493; VertNet |
| Ecuador | Sucumbíos | Napo Wildlife Center | Reptiles of Ecuador book database |
| Ecuador | Zamora Chinchipe | El Pangui, 6.8 km N of | iNaturalist; photo examined |
| Ecuador | Zamora Chinchipe | Reserva Maycu | Pazmiño-Otamendi 2020 |
| Ecuador | Zamora Chinchipe | Tundayme, 3.7 km E of | MUTPL 395; GBIF |
| Peru | Amazonas | Huampami | MVZ 163310; VertNet |
| Peru | Amazonas | Zona Reservada Santiago Comaina, 10 km S of | USNM 566605; VertNet |
| Peru | Loreto | Andoas, 8.8 km N of | USNM 204176; VertNet |
| Peru | Loreto | Iquitos | SDNHM 64407; VertNet |
| Peru | Loreto | Manití, 7 km N of | MPM 11266; VertNet |
| Peru | Loreto | Medio Putumayo–Río Algodón | Chávez et al. 2016 |
| Peru | Loreto | Mishana, Rio Nanay | TCWC 42185; VertNet |
| Peru | Loreto | Moropon | TCWC 44297; VertNet |
| Peru | Loreto | Pebas | CAS 12496; VertNet |