The terciopelo is the ultimate pit viper, responsible for more snakebites than any other.

Health · Published 3 October 2026 Swipe more like this →

In short: Known as the terciopelo, this formidable pit viper is the most prolific snake in the Americas. Its defensive nature, massive size, and potent venom yield have earned it a fearsome reputation. While it prefers to avoid humans, its proximity to settlements makes it a significant, and often dangerous, public health concern.

The terciopelo (Bothrops asper) is a large, sexually dimorphic viper found from Mexico to South America. Females grow significantly larger than males, reaching lengths up to 2.5 meters and weighing up to 6 kilograms. They possess proportionally massive fangs, typically 2.5 centimeters long. These snakes are nocturnal and solitary, often found near rivers or streams, where they use their heat-detecting pit organs to ambush prey. Their diet is remarkably broad, shifting from ectothermic animals in youth to endothermic mammals as adults.

This species is notoriously defensive, especially when cornered. It is known for being excitable and unpredictable, capable of moving quickly or even ejecting venom in fine jets from its fangs. In many regions, it is the primary cause of snakebite envenomation. In Costa Rica, it accounts for 46% of all bites, while in parts of Colombia and Venezuela, it is responsible for the majority of local snakebite fatalities. Bites cause severe symptoms, including local necrosis, systemic bleeding, and, in untreated cases, potential gangrene requiring amputation.

The venom's potency is so extreme that it can even affect didelphine opossums, which are typically immune to other pit viper venoms. This suggests an evolutionary arms race between the snake and its prey. Modern medical interventions, such as the antiophidic sera developed by the Clodomiro Picado Research Institute, have drastically reduced fatality rates in places like Costa Rica, bringing them from 9% before 1947 to nearly 0% today. However, managing the complex local tissue damage, such as compartment syndrome, remains a significant clinical challenge.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

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