Added 23 January 2013.

A look at the Family Agamidae

Physignathus

Water Dragons

Introduction

Water dragons are among the better known and more popular of the agamid lizards, and have been kept in captivity fairly regularly since the 1990s. At the same time they do have certain requirements which must be met if they are to thrive, mainly a reasonably large vivarium with access to a body of water. The Chinese Water Dragon, P. concinncus, in particular is renowned for bashing its snout raw against glass, often leading to serious injury or infection. This can only be avoided by an appropriate sized enclosure, and sometimes by marking the glass so that the lizard can see it is a barrier. They have been likened to smaller versions of the Green Iguana, but unlike the latter consume more insectivorous prey. The Australian Water Dragon is unavailable as an import due to Australia's wildlife laws but has been bred in captivity and, for an Australian lizard, is relatively obtainable.

Boulenger listed the characteristics of the genus as follows: tympanum distinct; body more or less compressed; nuchal and dorsal crests present; no gular sac; strong transverse gular fold; tail round or more or less compressed; toes not lobate; femoral pores present, at least in the male. Both species are good swimmers.

Husbandry details are available in deVosjoli, Manthey and Schuster and Rogner. See also the index of agamid-related articles under Physignathus, as both species have been covered several times over the past 10 years or so.

More recently it has been proposed to move P. lesuerii into its own genus, Intellagama.

Species Name

Common Name

Distribution

Size

Notes

Physignathus 

P. cocincinnus 

Asian Water Dragon, Chinese Water Dragon 

E/SE Thailand, Cambodia, Vietnam, S China, poss. Burma

SVL to 25 cm, tail about 2½x SVL; max TL 90cm

In nature this species is normally found in evergreen forests or mixed evergreen/deciduous/bamboo forests [Stuart & Emmett] near water, often on branches overhanging streams. In captivity they are prone to snout injuries, so the cage must be a suitable size (deVosjoli suggests 6' for a pair) and arranged so that the lizards are less likely to run into the glass and injure themselves. Scalation details: canthus rostralis well marked; nostril nearer end of snout than orbit; rostral a little wider than high, bordered behind by 2 supralabials and 8 postrostrals; nasals rather small, surrounded by a ring of slightly elevated scales separated from rostral by 3 scales and from labials by 5 rows scales; about 10 rows separating nasals; 4-5 enlarged suboculars; 12 supralabials, 11 infralabials; dorsal head scales minute, granular, keeled, a little enlarged on canthus rostralis and supraorbital border (as per Taylor, slightly larger on snout than on rest of head); gular scales large juxtaposed granules, unequal on the sides, and 3-4 of posterior lateral ones largest and conical; series of 6-11 large shields on each side, parallel with infralabials. Dorsal scalation: scales equal, minute, granular, feebly keeled; nuchal crest composed of lanceolate spines supported by fold of skin covered in granular scales, spines being short in young males but very long in adult males; dorsal crest similar, slightly lower on shoulders but continous with nuchal crest. Ventral scalation: scales larger, imbricate, smooth.Tail: strongly compressed; crest as developed as, but not continous with, dorsal crest; lower caudal scales enlarged and strongly keeled. Other: head moderately elongate; snout slightly longer than diameter of orbit; tympanum one third diameter of orbit; 11-18 molar teeth on each side of upper jaw and 12-18 on each side of lower jaw; limbs long, covered with minute, slightly imbricate, keeled scales; 3rd and 4th toes subequal with 22 lamellae on underside, each with 2 keels; 4th toe very much larger, with 2-3 rows of irregular scales underneath and about 34 scales in each row; 4-5 (sometimes up to 8?) pores under basal part of each thigh. Coloration: overall green, a little lighter ventrolaterally; indistinct narrow transverse bands of a lighter colour on the sides; enlarged gular shields and tubercles whitish; tail with dark-brown annuli. Reproduction: males have swollen cheeks; females can be distinguished by lack of crests; clutch of 8-12 eggs laid in exposed sandy patch in stream bed; hatching takes 9-10 weeks. [SOURCES: Boulenger, Cox et al, Taylor]

P. lesuerii

Brown Water Dragon, Australian Water Dragon

Australia (E Queensland, E NSW and E Victoria), S New Guinea

8"/20cm SVL, tail about 2½ x SVL

Similar in habitat to P. cocincinnus, being found on the banks of watercourses and also banks of lakes and in some coastal areas where it forages among rocks. Diet includes insects but also frogs, fish, crabs and flowers, fruit and berries, and according to Manthey and Schuster, sometimes young individuals, who therefore avoid adult hunting areas. Wilson and Swann state that this species thrives in urban areas, including Canberra, Sydney and Brisbane. Scalation details: canthus rostralis, supraciliary and supraorbital borders form slight ridges; dorsal head scales very small, very strongly keeled; occiput and temple with numerous conical and compressed tubercles; gular scales subimbricate, indistinctly keeled, intermixed laterally with enlarged suboval tubercles forming irregular longitudinal series; some of the hindermost of these tubercles are conical; row of slightly enlarged shields on each side, parallel with infralabials. Dorsal scalation: nuchal crest composed of a few triangular compressed spines; dorsal crest a serrated ridge; dorsal scales roundish, keeled tubercles forming irregular transverse series. Ventral scalation: scales larger than dorsals, imbricate, keeled. Tail: strongly compressed, crested like the back, dorsolateral scales very small and intermixed at base of tail with enlarged tubercles; ventral scales larger. Other: head moderately elongate, large and thick in the male; snout slightly longer than the diameter of the orbit; tympanum half diameter of the orbit; limbs long, scaled like the back; 12-22 femoral pores on each side. Coloration: overall grey to grey-brown (“dark olive” per Boulenger), with darker and lighter transverse bands that become rings or transverse bands on the tail; often a broad black band from eye to above the shoulder, involving the tympanum; belly pale olive, dotted with black; throat with black longitudinal lines in young, according to Boulenger; . Some populations have chest and anterior abdomen flushed with dark red, or chest, head and throat flushed with green, or (in south, presumably the Gippsland Water Dragon) throat marked or striped with orange, red, blue, green and yellow [Cogger]: Manthey and Schuster state that the ventral area is yellowish to brown in females and reddish in males, which would perhaps tally with the northernmost subspecies the Eastern Water Dragon. Reproduction: a clutch of 6-20 eggs is laid at some distance from the territory in spring [Manthey and Schuster], which might have ramifications for breeding in captivity; incubation time is 70-120 days. Manthey and Schuster also suggest that more than 2 clutches per season may be possible and give breeding suggestions [SOURCES: Boulenger, Cogger, Manthey and Schuster, Wilson and Swan]

P. l. lesuerii

Eastern Water Dragon

Australia (C NSW to Cape York Peninsula, Qld)


Coloration: as per species description, with red flush on chest [SOURCE: Wilson and Swan].

P. l. howittii

Gippsland Water Dragon

Australia (E Victoria to SE NSW)


Coloration: generally lacking stripe behind eye; dark body bands reduced; dark olive green on chest; mature males have black throat blotched with yellow, orange and sometimes blue [SOURCE: Wilson and Swan].

Bibliography

Links

Tricia's Chinese Water Dragon page has been going for over a decade now.

The Australian Museum offers a set of husbandry guidelines for the Australian Water Dragon.

See also the index of agamid-related articles, which has several listed for the two species.