Spider Tailed Horned Viper: Horrible or Not?

Spider tailed horned viper, the name is good enough to make a fearful atmosphere! Isn’t it?

Well, we are going to have a brief knowledge about a Persian viper snake species: Pseudocerastes urarachnoides, which is typically endemic to western Iran and was originally described in 2006. Since its discovery, this has become very popular due to its highly modified tail and very interesting caudal luring behavior.


The tale of the tail: An unique modification!


Spider Tailed Horned Viper: the modified tail
The modified tail

The tail of Pseudocerastes urarachnoides is highly modified to form a spider-shaped lure, hence this is called spider-tailed viper. The specific name urarachnoides is derived from ancient Greek, which means uro: tail, arachnoid: like a spider or arachnid.

The tail tip of the spider-tailed viper is inflated into a bulb-like shape. There are 15 pairs of subcaudal scales, and the drooping scales on the sides of the tail are elongated and appear like appendages of an arthropod.


Caudal luring: A unique characteristic of Spider Tailed Horned Viper


Caudal luring is a form of aggressive mimicry in which a predator uses tail movements to attract prey. On the other hand, the prey animal misinterprets the tail as a worm-like species or another smaller prey and unwillingly enters the danger zone. Once the prey animal is within striking range, the predator attacks. If the prey is lucky enough, can escape the clutch of the predator. Unfortunately, this predator misses its prey very often.

The tip of the tail is used as a lure in several species of snake including Bitis caudalis, Crotalus cerastes, Sistrurus catenatus, Agkistrodon contortrix, Acanthophis antarcticus, Acanthophis praelongus, Morelia viridis, etc. But none of them got a unique elongated scale that can provide gives the appearance of arthropod appendages.

A highly specified tail tip of the spider-tailed viper is lurking around, mimicking a wandering spider and used to lure insectivorous small animals to come within striking range.

Juvenile snakes have a smaller lure compared to the size of adults’ lure and are much more effective in attracting the prey, as it is closer to the size of the worm-like prey.


False-horned spider tailed viper


Spider Tailed Horned Viper: False horn

Spider-tailed snakes are often referred to as horned vipers, but actually, they are false-horned species. The horn-like structures above their eyes are made up of numerous small scales and hence the generic name is Pseudocerastes (pseudo means false). This is in contrast to the true-horned viper, Cerastes cerestes, which has a similar supraorbital spine like small horns, each consisting of a single elongated scale. There are about 16 to 17 scales between the horns. Cerastes cerestes are commonly known as Saharan horned viper. They habitually bury themselves in the sand where the horns are possibly used to keep sand away from covering the eyes.

By the way, the typical species got a spider-like tail and a horn (even though it’s a false horn), thus simply the snake achieved its sweet name, “Spider Tailed Horned Viper” or scientifically Pseudocerastes urarachnoides.


A Perfect example of camouflage


It’s easy to miss the spider-tailed viper in its habitat. Its skin is rippled with very rough, corrugated light and dark shaded scales that resemble the glittering hills of gypsum and limestone where it is often found. Although the Spider Tailed Horned Viper found in western Iran more than a decade back, many of its characteristics are still unknown due to its rarity. However, its characteristics help to perfectly camouflage against the rocky rugged natural environment.

The species is medium-sized and takes silent refuge in rocky beds and blends itself so neatly that you often won’t see until it strikes prey which can happen in less than a second! The habitat situation and the behavior of the species suggest that it should have only short movement. Characteristic rough scales help the snake to grab the rocky surface tightly while attacking prey at lightning speed, in just 0.2 seconds.

[ See how they captured a photo of spider tailed horned viper]


Can a spider tailed horned viper kill you?


The family Viperidae consists of venomous snakes. The quality and quantity of venom vary from species to species. Some vipers are lethal to human-being.

The bite of spider tailed horned viper is not fatal. Their venom is used to catch their prey, which commonly consists of insectivorous small birds like warblers from the genus Acrocephalus. Also, small lizards, rodents, and amphibians sometimes fulfill their meal.

Viper venom is vasculotoxic, damages the vascular tissues, and has necrotizing local effects. So, if the spider-tailed viper bite left untreated it may cause loss of damaged organs. But it can’t kill human beings.

+ posts

Ms. Subhra Das is a biology teacher in high school by profession. Besides she is a passionate science writer and nature lover.

As a teacher, she never restricts herself within the four walls of the classroom, rather she loves exploring the crude science behind the natural facts that include human and animal health, critical diseases, typical characteristics of wildlife, and mother nature.

Ms. Subhra Das is also a passionate traveler and explorer; she always tries to uncover natural flora and fauna at every destination she travels.

Leave a Comment