"Laboratory" Animals
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Lampropholis: the new "laboratory" animals Shelley Burgin Faculty of Science and Technology, University of Western Sydney — Hawkesbury, Richmond, NSW 2753 ABSTRACT Two spsciGs of Lsmpropholis skinks, LQmpropholis dslicdtd and Lsmpropholis guichenoti, commonly referred to as Penny or Garden skinks, have a predilection for disturbed areas. Both species have a widespread distribution over much of eastern Australia. Throughout most of their ranges they occur in overlap in a variety of habitats both disturbed and undisturbed, including suburban gardens. It is proposed that these species would make appropriate "laboratory" animals for undergraduate teaching, particularly animal ecology. They adapt well to captivity providing they are provided with adequate space and cover, food, water, and other appropriate environmental conditions such as light and temperature. Their attributes include adaptive capacity to captivity, small size, ease of capture Downloaded from http://meridian.allenpress.com/rrimo/book/chapter-pdf/2644390/rzsnsw_1993_041.pdf by guest on 24 September 2021 and abundance. Also addressed are animal welfare issues of captive housing and use of native species in teaching. INTRODUCTION As "laboratory" animals they are ideal. Their small size, abundance, ease of capture either Past generations of Australian biologists are by hand or pitfall traps, and adaptation to familiar with both the ubiquitous laboratory rat artificial housing make them appropriate Rattus norvegicus and Cane Toad Bufo marinus. animals for a range of undergraduate studies Their dissection has generally been a basic encompassing animal behaviour and ecology. component of first year undergraduate train- ing. Subjects taught in subsequent years also They adapt readily to life in an aquarium (or have their "typical" animals. It is inconceivable other appropriate "cage"), providing they have to imagine that anyone could call themselves a sufficient space, cover, food in the form of Genetics student without having handled large Drosophila sp. and water. If they are only being numbers of Drosophila melanogaster; while many kept short-term, no special arrangements are of us learned all we know about mark, release, required to control temperature and light. recapture techniques using a tray of flour However, if kept in captivity for extended swarming with Tribolium sp. periods of time, they need to have access to direct sunlight or heat lamps, otherwise they With appropriate technical support, estab- may encounter problems moulting. They lished animal houses and/or assured supply, also need to have appropriate lighting and the approach was safe, but boring. In recent temperature regimes for follicular develop- years, with greater concern about ethics, ment since it is associated with day-length financial constraints and increased numbers of cycles and a minimum temperature of 20°C is students, it has become increasingly difficult required for their development. and expensive to ensure our yearly supply of laboratory animals. I also perceive another Two species, Lampropholis delicata (De Vis "problem" with this traditional approach: none 1888) and Lampropholis guichenoti (Dumeril and of these species are Australian natives. Austra- Bibron 1839), are better known than their lian alternatives exist, for example the small congeners and are abundant in urban areas of reptiles. the Australian east coast (Burgin 1989). SCINCID LIZARDS BIOLOGY OF AS "LABORATORY" ANIMALS LAMPROPHOLIS DELICATA Small diurnal scincid lizards are widely Lamoropholis delicata is small, animals distributed throughout eastern Australia. One observed in Sydney weighed as much as 1.1 such group, the Lampropholis, are sufficiendy gm with a maximum total length of 82.5 mm. abundant to have gained the common names They occur in open forest types from south- Garden or Penny Skinks. Due to their pre- eastern South Australia through southern dilection for disturbed areas, Lampropholis are Victoria and eastern New South Wales to frequently abundant in areas of human habita- northeastern Queensland (Cogger 1992). In tion, including parklands, urban gardens and addition the species occurs in eastern Tasmania adjacent bushland. (Green 1981) and has been introduced to Herpetology in Australia 279 Hawaii (Baker 1979; Loveridge 1934; Oliver Clutch size in oviparous species is known to and Shaw 1953) and New Zealand (Hardy be correlated with female size. Baker (1979) 1977). This species will therefore be endemic suggested that the relatively smaller size to the campuses of most universities in Queens- attained by female L. delicata on Oahu Island land, eastern New South Wales, Victoria and (Hawaiian group) may have been a result of South Australia. greater competition (both intra- and inter- specific), than occurred on the islands of Kauai Baker (1979) commented that L. delicata was or Hawaii. Since individuals from the Hawaiian widely distributed in urban habitat, from dry Islands grow to a significantly larger body size lowlands to wet upland regions. As with other than Australian L. delicata, this phenomenon species of the genus, its preferred microhabitat may be attributed to lower predation pressure varies with prevailing weather conditions. In on the exotic populations, allowing individuals general the species tends to be associated with to live longer and therefore attain a greater sun flecks under canopy in areas with relatively body size and consequently larger clutch size. uniform, although open, cover. However, in Observations of predation give some basis for cooler areas, such as the Notophagus moorei rain- the prediction that larger females are at greater forests on the New South Wales/Queensland Downloaded from http://meridian.allenpress.com/rrimo/book/chapter-pdf/2644390/rzsnsw_1993_041.pdf by guest on 24 September 2021 boarder, individuals are more commonly predatory risk, at least immediately preceding observed in the open, along road and track oviposition (Burgin 1989). verges, rather than in more sheltered areas. This behaviour is also common during the BIOLOGY OF cooler months in warmer parts of the species' LAMPROPHOLIS GUICHENOTI range, although in cooler areas they will Lampropholis guichenoti is the larger of the two hibernate during cold periods. Outside of closed forest habitats, L. delicata tends to species. Animals from the Sydney population be restricted to areas of permanent cover may weigh as much as 1.4 gm and have a representing relatively moist microclimates, maximum total length of 86 mm. Their range such as logs and rock piles (Belmont 1977). It extends from southeastern South Australia is also frequently observed in more open through most of Victoria and eastern New habitat (including urban gardens and park- South Wales to southeastern Queensland. lands) in association with relatively deep litter, Within this range the species is broadly in over- such as at the base of mature eucalypts or in lap with L. delicata, although L. guichenoti tends other appropriately moist areas (Burgin 1989). to tolerate a drier micro-climate than L. delicata. Both achieve similar body temperatures in the Clarke (1965) recorded that the young hatch field, despite L. guichenoti preferring air in summer and reach maturity in the following temperatures approximately one degree year. Joss and Minard (1985) studied a Sydney warmer than L. delicata (Graham 1987). Where L. delicata population. They confirmed that the habitats of the two species overlap, L. oviposition occurred in summer while ovaries guichenoti is invariably in more open areas than were quiescent during autumn and winter (i.e., L. delicata, although frequently both species are February to July). Between August and October associated with disturbed areas (Burgin 1989). follicles grew, with one or two per ovary Joss and Minard (1985) observed that in the becoming vitellogenic, and these were ovulated Sydney region L. guichenoti had a similar repro- in October or November. After eggs were laid ductive cycle to L. delicata. However, (approximately one month later), a second wave of vitellogenic follicles occurred, subsequently in seasons of high rainfall, L. guichenoti may these regressed, post-mating in late summer. produce two clutches of eggs in a single season. Males produced mature sperm during October Other observations also indicate that this may and November, and again in February. Testes be the case (Milton 1980, Brisbane area; are depleted of sperm by the end of autumn. Pengilley 1972, southeastern Highlands of The females thus carry sperm over-winter and New South Wales), although Milton (1980) developed eggs are fertilized in spring. suggested that his observations coulcl also be explained in terms of the species breeding While small individuals occasionally have a later in southeastern Queensland. On the New single egg, two is more common. Within Aust- England Tableland (northern New South Wales), ralia females generally carry three eggs, with however, the species apparently produces only large individuals occasionally producing up to one clutch annually with recruitment begin- five (Burgin 1989). However in Hawaii female ning in February, subsequently juveniles grow L. delicata may produce as many as seven eggs rapidly and both sexes reach maturity in eight (mean clutch size on Hawaii 4.7; range 3-7) to nine months (Simbotwe 1985), growth rate although among islands, female egg numbers then decreases (Heatwole 1976; Simbotwe vary (Baker 1979). 1985). Egg incubation requirements of the two 280 Herpetology in Australia