The Chinese water dragon (''Physignathus cocincinus'') is a species of

agamid Agamidae is a family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview Phylogenetically, they may be sister to the I ...

lizard native to

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

and

mainland Southeast Asia Mainland Southeast Asia, also known as the Indochinese Peninsula or Indochina, is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to the west an ...

. It is also known as the Asian water dragon, Thai water dragon, and green water dragon. The genus name is Greek for "inflated jaw".

Description

Chinese water dragons can grow up to 36" (0.9m) in total length, including tail, and can live from 10 to 15 years. Coloration ranges from dark to light green, or sometimes purple with an orange stomach. Diagonal stripes of green or turquoise are found on the body, while the tail is banded from the middle to the end with green and white. Their undersides range from white, off white, very pale green, or pale yellow. But their throats are considered to be more attractive, which can be quite colorful (blue and purple, or peach), some with a single color, some with stripes. Adult males have larger, more triangular heads than females, and develop larger crests on the head, neck and tail, and are larger in general. The tail, slightly over two-thirds of the entire body length, can be used as a weapon, for balance, and to assist swimming. Like many other reptiles the Chinese water dragon possesses a small, iridescent,

photosensitive Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light. In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicity. ...

spot between their eyes referred to as the

pineal eye A parietal eye, also known as a third eye or pineal eye, is a part of the epithalamus present in some vertebrates. The eye is located at the top of the head, is photoreceptive and is associated with the pineal gland, regulating circadian rhythm ...

(or parietal eye, or colloquially as the third eye) that is thought to help

thermoregulate Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

their bodies by sensing differences in light to assist with basking and seeking shelter after sunset. Since it recognizes differences in light, the parietal eye can also help the lizard avoid predation from birds and other aerial threats, and can awaken from deep sleep from even slight changes in light from overhead. These animals are very docile and allow physical activity.

Habitat and behaviors

Native to the lowland and highland forests of southern

and southeastern Asia (

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

Laos Laos (, ''Lāo'' )), officially the Lao People's Democratic Republic ( Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ, French: République démocratique populaire lao), is a socialist ...

Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailand t ...

and

Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

), Chinese water dragons are most commonly found along the banks of freshwater lakes and streams. Water dragons live in areas with average humidity levels of 40–80% and temperatures ranging from 80–90 °F (26–32 °C). They are active during the day (diurnal), and spend most of their time in the trees or plants (arboreal). If threatened, the dragon will drop from the trees into the water and either swim to safety or remain submerged for up to 90 minutes.

Diet

Though they will also eat vegetation, the diet of the water dragon consists mainly of insects, supplemented with an occasional small fish, mammal, bird, reptile or egg. Mollusks and small crustaceans are also part of their diet.

Reproduction

Chinese water dragons normally

reproduce sexually Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...

, but sometimes reproduce by

parthenogenesis Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...

instead.

Invasive species

Chinese water dragons have established themselves in

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...

, probably from released pet animals.

Gallery

Chinese Water Dragon (Physignathus cocincinus) - Khao Yai National Park - 2.jpg, Head -

Khao Yai National Park Khao Yai National Park ( th, อุทยานแห่งชาติเขาใหญ่, , ) is a national park in Thailand. Established in 1962 as Thailand's first national park, it is the third largest national park in Thailand. Descri ...

, Thailand Chinese Water Dragon (Physignathus cocincinus) - Khao Yai National Park - 3.jpg,

, Thailand Physignathus cocincinus chinese green water dragon toronto zoo jan 08 1.jpg, Detailed view of legs and scales Physignathus cocincinus chinese green water dragon toronto zoo jan 08 2.jpg, Detailed view of head

References

External links

Care for Chinese water dragonChinese water dragon care sheet
{{DEFAULTSORT:Chinese water dragon Agamidae Reptiles of Myanmar Reptiles of Cambodia Reptiles of China Reptiles of Laos Reptiles of Southeast Asia Reptiles of Thailand Reptiles of Vietnam Reptiles described in 1829 Taxa named by Georges Cuvier