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
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 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, 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
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 dragon
Chinese 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