Azemiops

Azemiops is a special group of vipers known as Fea's vipers. This group includes two species: A. feae and A. kharini. They are found in the mountains of Southeast Asia, in China, southeastern Tibet, and Vietnam. These vipers are venomous, like all other vipers.

The first Fea's viper was collected by an Italian explorer named Leonardo Fea. It was described as a new kind of viper by a scientist named Boulenger in 1888. Scientists once thought these vipers were among the most basic types of vipers, but newer studies show they are closely related to pit vipers, a group known as Crotalinae.

Fea's vipers are unique because they are the sister group to pit vipers, meaning they share a common ancestor. Today, scientists recognize two species in this group, and they continue to study these fascinating snakes to learn more about their place in nature.

Description

Fea’s vipers are small snakes, not growing longer than about 77 centimeters. They are considered one of the most basic types of vipers. Unlike many vipers, they have smooth scales on their backs instead of ridged ones, and their heads have large plates instead of many small scales.

These vipers have short, hollow fangs and small venom glands. They lay eggs and hibernate in winter. Their coloring is striking, with a shiny blue-gray to black back marked by thin white-orange bands. The head is orange to yellow with a gray pattern, and the belly is olive-gray with small lighter spots. Their eyes are yellowish with vertical pupils.

Geographic range

These snakes live in parts of northern Vietnam and southern China, including areas like Fujian, Guangxi, Jiangxi, Guizhou, Sichuan, Yunnan, and Zhejiang. They are also found in southeast Myanmar and southeast Tibet. The place where these snakes were first discovered is called the Kakhien Hills in Myanmar. The two species live on either side of the Red River, with A. kharini to the east and A. feae to the west.

Habitat

These snakes live in mountainous areas up to 1000 meters high, where they like cooler weather around 20-25 °C. You might find them near roads, in tall grass, rice fields, or even close to homes. In Vietnam, they enjoy bamboo and tree fern forests with open spaces, lots of rotting plants on the ground, rocks, and small streams. They like moist places to hide and are most active at dawn and dusk.

Behavior

When this snake feels threatened, it flattens its body to look bigger and its head takes on a triangular shape. Sometimes, it will also shake its tail. If needed, the snake will strike, possibly using its fangs to defend itself. Some scientists think this snake is active during the daytime, especially from early March to late November.

Feeding

These snakes eat small mammals. One young snake that was caught had eaten a type of shrew called the common gray shrew. When kept in a cage, they are not eager to eat, but when they do, they will eat very small mice, usually only at night. Sometimes, when they catch their food, they hold onto it tightly and don't let go right away.

Venom

Fea's viper has venom that looks a lot like the venom of Wagler's viper. Studies show that the enzymes in Fea's viper venom are similar to those in other viper venoms. However, this venom does not affect blood clotting, cause bleeding, or damage muscle tissue. One special toxin in their venom, called azemiopsin, can block certain receptors in muscles that help them work.