Genus · Colubridae
Ptychophis
The genus Ptychophis contains a single species. It is not considered dangerous to humans.
About fanged water snakes
A tiny South American genus of small, semi-aquatic colubrids built around streamside life.
Ptychophis is a small genus in the family Colubridae, the largest and most diverse snake family on Earth. It contains a single recognized species, Ptychophis flavovirgatus, often called the fanged water snake. As a colubrid, it belongs to the vast assemblage of mostly slender, agile, egg-laying or live-bearing snakes that dominate snake diversity across the world, and within that family it sits among the New World ground and water snakes of South America rather than among the true vipers or elapids.
The genus is native to South America, with records centered on southern Brazil. Like many small colubrids tied to water, it is associated with moist habitats near streams, marshes, and other freshwater edges, where low vegetation and leaf litter provide cover. Members are small and slender with the typical colubrid look: a head only modestly distinct from the neck, smooth to lightly keeled scales, and a patterned body that helps it disappear against wet ground and bank vegetation. The common name points to enlarged rear teeth rather than to the long front fangs of a viper.
Ptychophis is a rear-fanged colubrid, meaning any enlarged grooved teeth sit at the back of the upper jaw rather than at the front. The great majority of rear-fanged colubrids are harmless to people and pose no medical threat, and there is no evidence this small, secretive snake is dangerous to humans. That said, no wild snake should be handled. Identification in the field is difficult and easy to get wrong, so treat any unfamiliar snake as best left alone, give it space, and let it move off on its own. If a bite from any snake occurs and you are unsure of the species, or if symptoms develop, contact emergency services or US Poison Control at 1-800-222-1222 and seek medical care; do not rely on field identification for a safety decision. As a small colubrid near water, its diet and behavior fit that niche, with such snakes typically feeding on small aquatic and ground prey and remaining low-profile and reclusive rather than confrontational.
Ptychophis belongs to the Colubridae family (Colubrids). The largest snake family, and the one most snakes you meet belong to. Typically round pupils, a head only slightly wider than the neck, and no heat-sensing facial pit or rattle. Scales may be smooth and glossy or keeled and matte depending on the species.
Danger: Almost all colubrids are harmless. A small number are rear-fanged with medically significant venom, the boomslang and the twig (vine) snakes of Africa being the dangerous exceptions. Most colubrids will flee or bluff rather than bite.
All species (1)
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