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Chinese Water Dragon

Physignathus cocincinus

The tropical, aquatic cousin of the Iguana. A gorgeous mint-green lizard with spiky crests, deeply beloved for its generally docile and tame nature. However, it is an animal of extreme husbandry complexity: it requires enormous vertical enclosures featuring a massive, deep, heated pool of water for diving (being semi-aquatic), and almost inevitably suffers devastating head trauma if kept in barren glass tanks.

Family
Agamidae
Origin
Sud-est Asiatico
Origin
Extra-Amazon South AmericaSouth and Southeast AsiaEast Asia
Tank use
Used in 0 tanks

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Species challenges
Temperature

25 °C - 32 °C

pH

n/a

Water type

Terrestrial / Freshwater

Basking spot

32 °C

UVB

High

Description

Geographical Origin and Habitat: Evergreen montane rainforests and dense jungles of Thailand, Vietnam, Cambodia, and southern China. It never leaves the thick branches of trees that overhang directly above crystal-clear freshwater streams. At the slightest hint of danger, it executes spectacular swan dives from the high branches straight into the river below, where it can remain submerged holding its breath on the bottom for nearly half an hour.

Taxonomy and Genetics: Agamidae family. An agamid of impressive size, often wrongly considered the 'insectivorous, handleable version' of the Green Iguana. Its coloration is an iridescent emerald green, with a creamy white chin sometimes bordered in brilliant cobalt blue, and vertical black bands on its laterally compressed long tail (perfect for swimming like an oar).

Behavior and Habits: Extremely visual and highly active. They are brazenly curious but easily spooked by sudden movements. Tragically, they NEVER recognize clear glass as a physical barrier: to the water dragon, if it can see the room outside, that is open explorable space, and it will explode into neurotic dashes, throwing itself face-first against the glass pane with horrific aesthetic consequences.

Morphology and Sexual Dimorphism: Imposing males, reaching up to 3 feet (90-100 cm) in length (two-thirds being the tail) with substantial weight; females are noticeably more modest, at around 2 feet (60-70 cm). Adult males develop towering nuchal and dorsal crest spikes (which females barely possess), massive blocky jowls colored with orange or cobalt blue throat patches, and extremely powerful jaws meant for crushing large crustaceans in the wild.

Care and observations

Terrarium Setup: AN INCUBATOR OF MISTAKES. The Water Dragon requires an immense paludarium (minimum 6 feet tall x 5 feet wide x 3 feet deep / 180x150x90 cm for a male). It must contain robust vertical synthetic vines and branches for climbing high up, and ON THE FLOOR a massive pool of clean water, deep enough for the entire animal to swim without touching the bottom, filtered by a heavy-duty external aquarium canister filter. IT IS MANDATORY to cover the glass sides or mask the bottom half with cork or visually dense plants: bare transparent glass will induce them to 'Rostral Rub' continuously until they sand away their facial bones and teeth.

Lighting and Heating: Forest-dwelling heliothermic reptiles. They demand high, humid air temperatures: 80-84°F (27-29°C) ambient, a basking spot of 90-93°F (32-34°C) on the highest, driest branches, with a nighttime drop to 75°F (24°C). The massive water pool on the floor must be heated with an aquarium heater to 77-80°F (25-26°C). Exposure to high-grade UVB rays (T5 systems at 6-10%) is absolute and vital; without excellent solar irradiation, they collapse victim to horrific bone deformities at an alarming rate during their first two years of rapid growth.

Humidity and Hydration: Massive humidity (75-85%). Thanks to the huge pool of heated water at the bottom of the enclosure, maintaining high humidity is somewhat easier. Frequent warm misting completes the environment. They very often refuse to defecate on land, using the massive water tub as their personal toilet, forcing the keeper into maniacal daily cleaning and heavy biological filtration to avoid bacterial blooms and unbearable stench from the water.

Feeding and Supplementation: Insectivore-heavy omnivores. Daytime diet: a storm of large crickets, locusts, huge roaches (Dubia), and superworms. Roughly once or twice a week it is crucial to offer large, whole earthworms (clean nightcrawlers) and occasional live feeder fish (healthy Guppies/Minnows free of thiaminase). They will accept minimal, sporadic amounts of sweet pulpy fruits and greens. Mandatory dusting with pure calcium at every juvenile meal, supplementing multi-vitamins every 10 days to prevent neurological deficiencies and myoclonic tremors.

Compatibility and Cohabitation: Territorial. A single male, never housing him with another male (penalty is mortal combat or chronic intimidation leading to the clinical wasting away of the submissive male). Small harems (one male, two or three females) only work in mastodonic heated greenhouses of 100 cubic feet. Unfertilized eggs frequently cause fatal egg-binding (dystocia) in females if they lack an isolated, extremely deep, warm dirt box to dig their nests.

Health and Common Diseases: Rostral Trauma (Snout Rubbing): The catastrophic trademark of the Water Dragon in captivity. Kept in narrow glass tanks, they jump against the crystal repeatedly; the skin of the snout tears into raw flesh, the facial bone rots from bacterial infection (Infectious Stomatitis / Mouth Rot), and the upper teeth fall out, permanently disfiguring the animal and causing death from brain abscesses. MBD (Metabolic Bone Disease) causing sudden spinal paralysis without proper T5 UVB tubes rigorously replaced every 6 months.

Reptile profile

Diet
Insettivoro
Humidity
70 % - 85 %
Ambient temperature
28 °C
Basking spot
32 °C
UVB
High
Adult size
90 cm
Minimum enclosure
1,200 L

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