The Mussurana Snake: Habitat and Characteristics

The mussurana is a very resistant specimen that isn't affected by the venom of other snakes, so it can feed on toxic snakes without any problem.
The Mussurana Snake: Habitat and Characteristics
Georgelin Espinoza Medina

Written and verified by the biologist Georgelin Espinoza Medina.

Last update: 27 December, 2022

Snakes are very heterogeneous reptiles with a great diversity of colors, sizes, and lifestyles. Although they don’t have legs, their bodies have enormous dexterity in their movements and speed. There are more than 3000 species in the world and one of them is called the mussurana, called the “blood viper” in some countries because of its intense red tone when young.

This snake belongs to the Colubrid family (Colubridae), and so it isn’t technically a viper. However, it is a snake that produces venom, an attribute that only some specimens of that family have. It’s also known as clelia clelia. Learn more about it in this article.

Habitat and distribution of the blood viper

The mussurana (Clelia clelia) is found in the Americas, with a distribution ranging from Mexico to Argentina. However, it isn’t found in Chile. It inhabits wooded areas and also cultivated areas, as long as they’re close to forests. Its range of distribution goes from sea level to 2000 meters (6560 feet) of altitude, although it’s estimated that it can be higher.

What does the mussurana snake look like?

The mussurana snake has an interesting appearance, since juveniles and adults have different colorations (as if they were two different species). When they’re juveniles they have an intense reddish tone all over the back of their bodies. However, their heads are black and they have a light band on the nape of the neck, followed by another black band.

Some specimens have dark spots in the region of the vertebral scales. The ventral area is cream and may have grey speckles. The body shape is cylindrical and it has eyes with wide pupils.

In its adult state, the blood viper is dark, with a bluish or black tone. It can grow very long (around 220 centimeters – 7.2 feet), especially the females, as they’re larger than the males. This means that there’s a clear sexual dimorphism, but not only with respect to size, but also in the number of ventral and subcaudal scales.

The behavior of the mussurana

This colubrid is very agile and moves easily on land, but has also been observed in water and even among trees. It usually forages for food at night, but is also active during the day.

When threatened, this snake tends to make cloacal discharges, a strategy that may seem strange but can be very useful. Other defensive behaviors include sudden changes in posture and hiding its head.

Feeding behavior of the mussurana

The mussurana is carnivorous. Its main characteristic is that it feeds o n other snakes (including some poisonous ones), which is why they are said to be ophiophagous.

Among the species preferred by the mussurana we have the Terciopelo, or Bothrops asper, and those of the genera Atropoides, Crotalus and Porthidium, among others. Their diet also includes other vertebrates, such as small mammals, birds, and lizards.

The mussurana snake is very agile in getting its prey. It uses two very important attributes, its venom and its ability to constrict: a lethal combination.

Their chemical arsenal isn’t so toxic, at least not for humans, as encounters aren’t usually fatal. It has opisthoglyphous dentition, which means that the fangs that inject the venom are on the back of the jaw.


The opisthoglyph is oviparous, which means that it lays eggs. Its clutch can contain from 9 to 22 eggs. It’s known that sexual maturity is reached when males have a size of 65 centimeters (just over 2 feet) and females 97.3 (3.2 feet).

In studies conducted in Brazil, a female fecundity of only 53% was observed, suggesting that only half of the adult females reproduce each year. In addition, it’s estimated that their reproduction is influenced by climate. Thus, in warmer regions, they have a continuous cycle and in colder regions it becomes seasonal.

Conservation status of the mussurana

The mussurana isn’t an endangered species. It’s listed as “Least Concern (LC)” according to the IUCN Red List of Threatened Species. International Union for Conservation of Nature (IUCN) Red List.

However, in Argentina, it’s classified as vulnerable, as human urban expansion means that it has fewer and fewer places to feed. In addition, we must take into account that it’s a specimen with low fecundity and late sexual maturity.

A very resistant snake

This reptile has another interesting feature: its high resistance to the venom of other venomous snakes, such as Bothrops, which are part of their diet. This event has been the subject of study by some researchers, fascinated by the innocuousness of these colubrids as they show no symptoms.

The Mussurana are impressive snakes, not only striking for their intense red coloration (in their juvenile stage), but also for their attributes. They consume other snakes with the help of their venom and their constrictor power, a combination from which their prey can’t escape. In addition, they show high resistance to other ophidian venoms, a fact of great interest in the scientific field.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Cerdas, L., & Lomonte, B. (1982). Estudio de la capacidad ofiofaga y la resistencia de la zopilota (Clelia clelia, Colubridae) de Costa Rica a los venenos de serpiente. Toxicon, 20(5), 936-939.
  • Díaz-Ricaurte, J., Serrano, F., & Ferreto, B. (2018). Clelila clelia (Daudin, 1803). Catálogo de anfibios y reptiles de Colombia, 4(2), 23-31.
  • Galarza, M., De Alencar, L., & Martins, M. (2013). Natural history of pseudoboine snakes. Papeis avulsos de Zoología, 53(19), 261-283.
  • Gutiérrez-Cárdenas, P., Rivas, G., Nogueira, C., Gagliardi, G., Catenazzi, A., Gonzales, L., & Murphy, J. (2019). Clelia clelia. The IUCN Red List of Threatened Species 2019: e.T197468A2487325.
  • Lomonte, B., Cerdas, L., Solórzano, A., & Martínez, S. (1989). El suero de neonatos de Clelia clelia (Serpentes: Colubridae) neutraliza la acción hemorrágica del veneno de Bothrops asper (Serpentes: Viperidae). Revista de Biología Tropical, 38(2), 325-326.
  • Scott, N., Giraudo, A., Scrocchi, G., Aquino, A., Cacciali, P., & Motte, M. (2006). The genera Boiruna and Clelia (Serpentes: Pseudoboini) in Paraguay and Argentina. Papeis avulsos de Zoología, 46(9),77-105.
  • Pizatto, L. (2005). Body size, reproductive biology and abundance of the rare pseudoboini snakes genera Clelia and Boiruna (Serpentes, Colubridae) in Brazil. Phyllomedusa, 4(2),111-122.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.