Elaphe carinata

Elaphe carinata, the king ratsnake, is a species of Colubrid snake found in Southeast and East Asia.

Description
Elaphe carinata is a large species of snake with total length up to 240 cm. It is an active, predatory snake that eats everything from beetles to birds to snakes, with particular preference for the latter.

Etymology
The common name refers to its habit of eating other snakes, including venomous species such as the Chinese cobra and the sharp-nosed viper. It suffocates its prey by constriction, similar to the hunting technique of boas and pythons. Elaphe carinata also preys on rodents and other small animals.

It is also known as Taiwan stink snake and stinking goddess which refer to this species' highly developed post-anal glands that are frequently emptied when the snake is picked up, resulting in a very strong, bad odour.

Classification
While there may be some speculation among herpetoculturists that the king ratsnake could be more closely related to the kingsnakes of the genus Lampropeltis than the other ratsnakes in the genus Elaphe, there is very little direct genetic relationship between the two genera. This perceived similarity is due in part to the dietary habits of the king ratsnake, in particular its preference for ectothermic prey such as snakes and lizards, and to the physical structure of the head, which is far less distinct than that of most rat snakes and closely resembles the elongated head and indistinct neck structure of the kingsnakes.

In actuality, they share much in common genetically with other Eurasian rat snakes such as the Russian rat snake (Elaphe schrenkii) and the Japanese rat snake (Elaphe climacophora). They may also share a common lineage with the genera Coelognathus, Gonyosoma and Orthriophis. External morphological characteristics and behavior alone are generally not considered reliable taxonomic keys to classifying relationships between species, as the majority of current classification is now based on DNA evidence. The superficial resemblance to American kingsnakes is more likely an example of convergent evolution, much like the similarities between the South American emerald tree boa (Corallus caninus) and the Indo-Australian green tree python (Morelia viridis).

Distribution
Elaphe carinata is found in China, northern Vietnam, Taiwan, and Japan (Ryukyu Islands).

Commercial use
Elaphe carinata is one of the major species in the snake trade in China, particularly in skin trade but also of live animals; it is the most commonly available snake in restaurants.

The king rat snake is also uncommonly found in the exotic pet trade.