AUSTRALIAN BIODIVERSITY RECORD - Calodema

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Australian Biodiversity Record, 2009 (3): 1-96 and back and base of the tail as in the south-coastal NSW population. There is always a thin creamish, golden or pale yellowish dorsolateral stripe that runs from just above and behind the eye, along the nape (where it may be dark-edged along the upper edge), and along most of the body, but this stripe is most intense on the anterior of the body. This species only rarely possesses an obscure pale streak that extends from behind the eye to above the ear opening. The upper lateral zone of the body is usually black with scattered pale yellow or creamish speckles or spots that may have an irregular vertical alignment to them. However, some populations may have the upper lateral zone brownish rather than black. The lower lateral zone is creamish or creamish-yellow with dense black flecking which may form a darker variegated pattern posteriorly, and a finer, darker peppering pattern anteriorly. The upper parts of the limbs are the same colour as the dorsum, but with black flecks and small blotches, and the side of the original tail may be heavily speckled with black; regenerated tails are plain brown. Ventrally, whitish to creamish or creamish-yellow, with the throat, chin and infralabials finely flecked with blackish or dark bluish, and sometimes with a series of thin blackish or greyish lines formed from fine dotting under the throat, chest and venter. Some significant features of this species morphology are: body scales smooth in sub adult and mature specimens, but distinctly keeled in neonates, and in 36-44 rows at mid-body; paravertebrals similar in size or barely larger than adjacent dorsal scales, and numbering 74- 88; prefrontals usually in broad contact; parietals in contact behind the interparietal; interparietal about 1.5 times longer than wide, and never separating parietals; supraoculars 4; mature specimens have the upper secondary temporals separated across the nape by four or five variable, obliquely aligned scales which contact the posterior margins of the parietals (usually comprised of 1-3 nuchals, plus the upper secondary temporals); supranasals usually absent; nasals separated; supralabials 7-8 (usually 7) (with 5 th or 6 th subocular); infralabials 7- 10, with postmental in contact with first two or three infralabials on each side; lower eyelid movable and scaly; supraciliaries 9-12; ear-opening present and conspicuous (larger than nasal scale); no anterior ear lobules; well-developed pentadactyl limbs that strongly overlap when adpressed; hind limbs much longer than forelimbs; 4th toe much longer than the 3rd; base of 4th toe broad, with most lamellae with a median groove, and divided basally; 24-34 subdigital lamellae (smooth) beneath 4th toe. Premaxillary teeth 7-9 (usually 9); Attains a maximum total length of around 350 mm., and a snout-vent length of about 140 mm, although most mature specimens would be slightly smaller, at around 280-300 mm in total length, and a SVL of around 100-120mm. Although females and males have similar snout-vent lengths, females tend to have larger body lengths. Variation in morphology suggests that this species is composite. There appears to be a taxonomically distinct population in the Mt Lofty Ranges of South Australia. An undescribed member of this species has also been known from mideastern and northern Queensland for nearly 50 years. A proposed Holotype (labelled as such) was even deposited in the Australian Museum by Eric Worrell, but his description was never published, I have examined this specimen and I am convinced that it is indeed a separate species quite distinct from quoyii. I have decided however to refrain from formally naming this species as Dr Glenn Shea has informed me that he is currently in the process of revising the Eulamprus quoyii complex. It is possible that Hinulia gastrosticta Günther, 1875 is applicable to one of these distinctive Queensland populations, and Wells and Wellington (1984) resurrected that species on the basis of the original description. However, I note also that Hutchinson and Rawlinson (1995) resynonymised Eulamprus gastrostictus with quoyii due to insufficient evidence that its earlier resurrection by Wells and Wellington was warranted. Although I have observed that “Eulamprus quoyii” exhibits quite distinct morphological differences in Queensland to that present in topotypic specimens from Sydney (the Type Locality of quoyii), I am now aware that there are at least two, possibly three distinct ‘forms’ of quoyii in Queensland. As the Type Locality of Hinulia gastrosticta Gunther, 1875 was given merely as ‘Queensland’, it is premature to assign this name to this or any other population in Queensland without examining the Holotype in the British Museum - which I am unable to do. The impending revision by Glenn Shea of the quoyii complex will hopefully resolve whether or not Hinulia gastrosticta is a valid taxon from Queensland, so I have accepted the decision of Hutchinson and Rawlinson and refrain from using the name further until the matter is resolved by Shea. Distribution: As currently defined, this species occurs over a large part of eastern Australia, ranging from about Cairns in north-eastern Queensland, south to the mid-south coast of New South Wales (including parts of the coastal section of the Australian Capital Territory at Jervis Bay), parts of the Murray-Darling River Basin of north-western and western NSW, north- 14
Australian Biodiversity Record, 2009 (3): 1-96 western Victoria and along the Murray River in South Australia; an isolated population also occurs in the Mt Lofty Ranges in south-eastern South Australia where it lives in association with the Torrens, Sturt and Onkaparinga Rivers. Habitat: It utilises a variety of coastal or near coastal vegetation communities (usually riparian), ranging from rainforest, wet or dry sclerophyll forest, open woodland, and essentially prefers the margins of melaleuca swamps, marshes, freshwater creeks, rivers, billabongs, and soaks. Also occurs along rocky ridges and cliff-lines in various open coastal woodland and sclerophyll forest communities. It can also be found quite close to the littoral and intertidal zones at some coastal locations, but usually where this occurs there is a freshwater stream or soak present. This species also extends well into the semi-arid interior along relatively permanent tributaries of the Darling River, principally the MacIntyre and Namoi Rivers, as well as the Murray River, but nowhere is the species as common here as it is on the coast. In the more developed coastal areas, it is successful at colonising or adapting to disturbed or regenerating environments such as farmland, polluted water courses, even urban concrete canals and drains in heavily urbanized and industrial areas of cities. In such disturbed situations, such as agricultural or urban environments, this species may persist in large numbers along heavily polluted watercourse with fringing vegetation that has been replaced by dense weedy infestation, such as lantana, Crofton weed, blackberry and privet. Biology/Ecology: Essentially a diurnal, terrestrial and semi-aquatic species that lives along the verges of permanent or semi-permanent watercourses, from sea-level to about 400 metres altitude. Often individuals may be found in areas distant from obvious water, but even in such situations, there is usually a non-perennial stream bed in the vicinity, or some sort of other body of standing water, such as a temporary soak, farm dam, or the area has moist microhabitat refuges like a rocky ridge or outcrop, or the area is well-vegetated. Basking sites are often logs or rocks, under which they retreat when disturbed, often into self-constructed burrow-like cavities. They will also utilise other animal’s burrows to escape predators, but the main escape strategy adopted to avoid predation is by rapidly running over land to shelter sites. They will dive into water if retreat over land is not an option, and when entering the water, they usually swim vigorously on the surface vegetation near shore, or dive underwater where they can remain for up to 10 minutes or so before surfacing. After leaving the water, specimens will immediately seek out a suitable basking site so as to rapidly recover the energy loss associated with swimming. Other shelter sites are hollow logs, rock crevices, soil cavities of exposed tree roots along the edges of watercourses, piles of flood debris, earth cracks and the burrows of other animals. In disturbed situations this species may be found sheltering in expansion grooves and drainage holes of concrete canals, along stone retaining walls of highways, beneath discarded rubbish lying on the ground - like old boards, sheets of corrugated iron, plastic, fibro, discarded garden wastes and the like. It has been observed that fairly large colonies of this species can be found where the outlets of stormwater pipes discharge into streams. This is an intelligent, highly active and common species that lives in small social groups at preferred sites. Adult males can engage in aggressive fights will each other, and on occasions will emit a high pitched squeak when fighting or when handled. The Eastern Water Skink is a viviparous species, with sexual maturity in females being reached at about 85-90 mm SVL, and age 3-4 in southern populations, but at year 2 in populations from North Queensland. Mating occurs in Spring and the young are born several weeks later in January-February (late Summer) in the southern part of its range. However specimens in the tropical part of its range in north Queensland, give birth during the Wet Season in December. Up to 10 live young (usually about 4-7) have been reported in a brood, but 3-4 is more usual in average-sized adults, and around 5-7 for larger females. However, although larger females across the species’ range generally tend to have larger litters, North Queensland populations have a higher number of smaller offspring in a brood than do the southern populations, which tend to have a smaller number of larger offspring. In diet, the Eastern Water Skink is generally an opportunistic omnivore, although it feeds mainly on small invertebrates which are actively hunted both on land and in water, On occasions small fruiting bodies of some plants are eaten, and even small vertebrates - mainly lizards, but also frogs (tadpoles and metamorphlings) are hunted as well, and large specimens have been known to eat small mammals (baby mice) in captivity. Known predators are mainly snakes such as Pseudechis porphyriacus, Notechis scutatus, Pseudonaja textilis, Cryptophis nigrescens and in coastal areas of eastern NSW - Acanthophis antarcticus. It is believed that several species of birds also prey on this species. Eastern Water Skinks are known to harbor a range of endoparasites, specifically pleurocercoids of skin worms, as well as other cestodes and 15
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AUSTRALIAN BIODIVERSITY RECORD - Calodema

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