Mexico is a megadiverse country, with a unique variety of natural regions stretching from Tijuana to Suchiate. Among jungles, deserts, forests, thickets and oceans, flora and fauna is national pride and world heritage.

However, natural wealth also includes life forms whose defense and hunting mechanism is poison production.

Although these are species that are not aggressive and generally attack when they feel in danger, they are manipulated or their habitat is invaded, a bite from one of the most poisonous animals in Mexico It should be treated as a medical emergency. These are the 5 species with the most toxic venom in the country and how to identify them:

Black widow

Photo: Wikimedia

Distributed by most of the national territory, the black widow (Latrodectus mactans) is a small spider characterized by its black body and a pair of deep red spots on the abdomen.

The venom of this small spider is very powerful and has neurotoxic properties, capable of causing paralysis in some muscles and severe pain, which can worsen if you do not receive the antidote quickly.

Although it is very difficult for your bite to be lethal, it is best to immediately see a doctor for a proper assessment.


Coral or coral snakes are present in Oaxaca, Chiapas, Guerrero, Veracruz and Chiapas. Unlike rattlesnakes, they are small and thin, they have intense colors in which orange stripes alternate with yellow, white and black rings, in addition to small eyes and an obtuse snout.

Cases of a coral bite must be treated as a medical emergency due to the powerful neurotoxins that make it one of the most poisonous animals in Mexico, with the potential to cause flaccid paralysis.

The symptoms of paralysis begin 20 minutes after the bite and the victims experience total muscle relaxation that can be stopped with an antidote; however, if the paralysis continues it can lead to death by suffocation if the paralyzing effects reach the diaphragm.

Violinist spider

A common inhabitant in the center (Mexico City, Puebla, Tlaxcala and Estado de México) and in the north of the country are spiders of the Loxosceles genus, popularly known as violinists.

It is one of the most poisonous animals in Mexico and despite its harmless appearance (which sometimes causes them to be confused with long-legged spiders), its bite is very powerful and the poison produces inflammation, pain and fever, in addition to decomposition in the affected tissues if the antidote is not taken quickly.

Although the fame of its poison commands respect, it is a shy animal that prefers corners and places where cleaning is not customary, such as attics, garages and rooms with tools and other objects that are not used often. Your bite occurs when it is pressed against the skin, by wearing a shirt, pants or shoe that has one inside.


Rattlesnake most poisonous animalPhoto: pxfuel

Mexico is the first place worldwide in poisonous herpetofauna, but that does not mean that its bites are a common cause of death. Although the 64 species of Mexico are of medical importance and there is at least one species in each state, the vast majority of bites occur when a specimen is handled without prior knowledge.

Rattlesnakes are easily recognizable by the sound they make when shaking the rattlesnake of their tails as a defense mechanism and although they are temperamental, their attacks are due to invasion of their habitat.

The species of this genus are considered one of the most venous animals in Mexico and can cause swelling in the affected area, very intense pain and sometimes tachycardia. In some severe cases where no antidote is used, the development of acute kidney failure is possible, which can lead to life-threatening complications.

Gila monster

Gila monster most poisonous animalPhoto: Wikimedia

In Mexico there are four species of poisonous lizards, all belonging to the Heloderma genus. Unlike lizards, iguanas, and the like, these are easily identifiable by their striking spotty and mole colors, plus a flat, thick snout.

The Gila monster, the scorpion, the jawed lizard, and the spotted lizard all have toxin poison that causes suffocation, pain, and hypothermia to their victims and use it as a defense mechanism. They are slow and heavy lizards, hence the bites of these animals are very rare in Mexico.

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