The animal kingdom, particularly the world of snakes, is filled with fascinating and surprising elements. In Vietnam, some notable venomous snakes include: King Cobra, Malayan Krait, Red-Whiskered Bulbul… Many species possess venom that can kill a person in an instant.
How to Identify Venomous Snakes in Vietnam
Biological Characteristics and Behavior
Snakes are a general term for a group of legless, elongated carnivorous reptiles. Like other scaled animals, snakes are vertebrates, lacking eyelids and external ears.
Their jaws are highly flexible, allowing them to swallow prey much larger than their head.
Snakes hunt in two main ways: using venom to paralyze their prey (in venomous snakes) and constricting their prey (in non-venomous snakes). However, most snake species are non-venomous; they usually avoid humans and only attack when provoked.
Due to their lack of legs, they primarily move by slithering. Their movement styles are quite diverse, including lateral undulation, sidewinding, or swimming. Venom serves not only for hunting but also as a defense mechanism for snakes.
Snakes can be found on every continent (except Antarctica) and in all types of terrain, even in the depths of the ocean or at elevations up to 4,900 meters.
Classification
There are over 20 families of snakes with 500 genera comprising 3,400 to 3,550 snake species worldwide, showcasing the remarkable adaptability and evolution of this species.
Due to this diversity, we will focus on venomous and non-venomous species commonly found in Vietnam.
Identification primarily relies on external characteristics such as color, head and body shape, and tooth structure. In Vietnam, there are two highly venomous families: cobras and vipers.
Vietnam is home to nearly 200 snake species, of which 53 are venomous, mainly belonging to the viper and cobra families.
Horned Viper
Scientifically known as Trimeresurus cornutus, this species is found in Vietnam. Its head is distinctly triangular compared to its neck, with small scales on the top of the head, and scales over the eyes developed into horns, hence it is known as the “devil snake.” Its body size is approximately 50 cm. The venom of the horned viper is ranked among the most dangerous snakes in Vietnam.
Red-Tailed Viper
Scientifically known as Trimeresurus albolabris, this is one of the most venomous types of viper, characterized by a green body and a reddish-brown tail. They primarily inhabit the high mountainous regions and deep forests of the Trường Sơn range in northwestern Vietnam, with sightings reported in Cần Thơ, albeit rarely. Recently, they were also reported in Quảng Ngãi and Nam Đàn – Nghệ An, and last year, they reached the city of Đà Nẵng.
Bamboo Viper
Also known as the dry leaf viper, its scientific name is Trimeresurus mucrosquamatus. It gets its name due to its skin color blending in with dry leaves and dead trees, making it extremely hard to detect. Commonly found in extensive rubber forests in Southeast Vietnam, this species is considered highly dangerous, second only to sea snakes according to Professor Nguyễn Lân Dũng.
Vogels Viper
Scientifically known as Viridovipera vogeli, this species has a green head and body, with a lighter belly. Scientists have not yet fully studied the diet of southern vipers. They are nocturnal, residing in shrubs and low trees in mountainous areas at elevations from 900 m to 1,500 m. This snake species is found in Gia Lai, Đồng Nai, and Lâm Đồng.
Silver-Headed Viper
According to Wikipedia, the silver-headed viper is scientifically known as Azemiops feae and is considered one of the most primitive venomous snake species. This medium-sized snake has a slightly flattened head, distinctly separated from its neck. It measures approximately 80 cm in length and inhabits mountainous areas up to 1,000 m. In Vietnam, this species is found in Cao Bằng, Vĩnh Phú, and Lạng Sơn. Its population in the wild is very limited.
Trùng Khánh Viper
Scientifically known as Protobothrops trungkhanhensis, this species was recently discovered by scientists in the Trùng Khánh Nature Reserve in Cao Bằng, Vietnam. The Trùng Khánh Viper measures about 70 cm, relatively small compared to other species in the Protobothrops genus. They inhabit elevations of 500 – 700 m in evergreen forests and tropical limestone rainforests.
Siamese Cobra
The Siamese Cobra, also known as the king cobra, has the scientific name Naja siamensis. It is a venomous snake that can be fatal. Cobras usually strike when they feel threatened or provoked. Anyone bitten by this venomous snake may die within about 30 minutes due to respiratory failure caused by the venom, leading to suffocation and paralysis of the diaphragm. Cobras primarily feed on rats, birds, and frogs. In Vietnam, they are mainly found in the Central South and southern regions.
King Cobra
The King Cobra, scientifically known as Ophiophagus hannah, is not known to actively attack humans, but it is still considered a dangerous and fearsome species within its habitat. Not only does it possess the ability to inject venom, but it can also control the amount of venom it delivers when biting its prey. The venom of the King Cobra contains neurotoxins that can paralyze the nervous system, causing the victim to fall into a coma and potentially die.
Earth Cobra
The land cobra, also known as one-eyed cobra or fat cobra, has the scientific name Naja kaouthia. When threatened, the neck of this snake expands in a frightening manner. Just a small amount of venom from this species can kill its prey unexpectedly.
Sea Snakes
Sea snakes belong to the scientific subfamily Hydrophiinae. They are venomous snakes that live in marine environments, having evolved from terrestrial ancestors. A common feature of sea snakes is their flattened, eel-like body structure. Unlike fish, sea snakes do not have gills and must frequently surface to breathe. Most sea snake species possess powerful venom. In Vietnam, they are known by various names such as rắn đẻn or rắn đẻn biển, and can be found in many coastal regions of the country.
Many-banded Krait
The many-banded krait (Bungarus fasciatus), also known as striped krait or black-and-yellow krait, belongs to the cobra family (Elapidae). This is one of the most venomous snake species; although they rarely attack humans, if bitten, the venom can kill the victim within minutes without timely medical intervention. They are commonly found in the lowlands, midlands, and mountainous areas of Vietnam. They hunt at night, preying on other snakes and occasionally lizards.
Spotted Leaf-nosed Snakes
The head of this snake can change to a light brown color, while the body is a deep orange or light reddish-brown. The patterns on the body may include large, widely spaced spots on the sides, irregularly shaped round spots, twisted black patterns along the back, and sometimes no patterns at all. The body and tail tip have a black band. The belly is pink, while the underside of the tail has asymmetrical black and white patches. They typically measure around 47 cm.
The patterns on the snake’s body can include large, widely spaced spots on the sides.
Females lay eggs once a year, producing two eggs each time. Their primary diet consists of small snakes, especially Typhlops sp. and lizards. They are venomous and dangerous. When threatened, they often raise their black and white underside and coil up to intimidate predators.
When cornered, they may play dead and emit a foul smell to deceive attackers. Typically, this nocturnal snake is found under debris, logs, and similar locations in dense forests at elevations of up to 1,000 meters.
Cat Cobra
Image: Trường Nguyên.
The cat cobra, also known as the Indochinese spitting cobra, is famous for its ability to spit venom up to 1.4-1.6 meters. According to Dr. Tình, the cat cobra typically has a V-shaped mark or a cat-like face on its head. This species is commonly found in the southern regions of Vietnam. When threatened, the animal expands its neck from front to back, unlike cobras that widen their necks sideways.
