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Thylogale billardierii (Desmarest, 1822), the Tasmanian pademelon, is a small macropodid now endemic to Tasmania; the other 5 species are on the Australian mainland or Papua, New Guinea. The body is compact with relatively long forelimbs compared with larger macropodids, short ears, and a tail two-thirds the head and body length that lies on the ground while at rest. The long pelage is dark brown above and yellow-to-rufous below. While running, its body lies more closely parallel to the ground than other macropodids. A browser more than a grazer, it occupies a wide range of habitats but is often associated with forest edges. Adults weigh 4–11 kg, and males are 50% heavier than females. At present, T. billardierii is secure, listed as “Least Concern”; it is threatened primarily by introduced carnivores.Version of Record, first published online September 25, 2018, with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.

Changes in milk composition (total solids, carbohydrate, protein, lipid and calculated gross energy content) during lactation in three groups of Tasmanian bettongs ( Bettongia gaimardi): free-living animals (wild group), captive animals offered a diet of dry dog food and apples ad libitum (ad lib group), and captive animals fed restricted amounts of the same diet (maintenance group) were related to growth rates (measured as body mass and head length) of their young. There were no significant differences in the concentration of milk solids among the three groups, but the wild group had higher lipid concentrations and the maintenance group had higher carbohydrate but lower protein concentrations. For all three groups, milk total solids increased through lactation from ca. 25% to ca. 45% and carbohydrate concentrations decreased from ca. 18% to about 3%. Protein concentrations increased from ca. 5% to ca. 10% in the wild and ad lib groups, but only from 4% to 8% in the maintenance group. Lipid concentrations increased in the wild and ad lib groups from ca. 4% to ca. 18%, but in the maintenance group only to ca. 7%. Calculated gross energy content of milk increased through lactation in the wild and ad lib groups (from ca. 500 kJ.100 ml(-1) to ca. 1,000 kJ.100 ml(-1)), but there was no significant increase in the maintenance group. The volume of milk produced increased to a peak just prior to permanent pouch vacation by the young, when the gross energy output in milk was 120-150 kJ.3 h(-1) in the wild and ad lib groups. On a daily basis this is equivalent to the milk energy output of larger wallabies, and helps to explain the relatively high growth rates of young Tasmanian bettongs. There were significant differences in growth rates among the groups, with the heaviest young always in the ad lib group. Thus differences in milk composition resulting from different planes of nutrition can lead to differences in growth rates of marsupial young.

Intersexual interactions in Tasmanian bettongs (Bettongia gaimardi) were observed in dyadic combinations. Several behaviours were associated with agonistic confrontations and occurred in predictable response sequences. There was no evidence of a consort period between males and pre-oestrous females. Overt sexual interactions occurred only on the night of oestrus, coincidentally with the maintenance of close spatial proximity. During copulation, multiple intromissions were regularly achieved but the intervals between successive bouts of these acts generally increased. Males were also observed to engage in regular attempts at social (urogenital) investigation and were apparently able to detect the reproductive state of all resident females, presumably utilising olfactory cues. The brevity of sexual interactions occurring between individuals contrasts with the more complex repertoire of the gregarious large macropodoid marsupials.

Relationships between testes weight, body weight and mating systems were examined in 40 marsupial species and in the extant monotremes. Relationships between relative testes weight and mating systems in marsupials resemble those previously described for primates. Thus relative testes weights are greatest in those marsupials where females mate with multiple males during the fertile period, i.e. polyandrous species (e.g. Antechinus flavipes, Isoodorr obesulus, Peranzetes nasuta, Potorous tridactylus, Macropus eugenii and M. agilis) and smallest in monandrous forms (e.g. Petauroides volans and Petaurus breviceps) where females usually mate with a single male. These findings are consistent with effects of sperm competition upon the evolution of relative testes sizes in marsupials. Where field studies on marsupial mating systems are lacking, we make predictions based upon examination of their relative testes weights. Tarsipes rostratus, Acrobates pygmaeus, Macropus rufogriseus and Sarcophilus harrisii are predicted to engage in multiple matings and sperm competition. Conversely, Lasiorhinus latifrons, Cercatetus concinnus and Pseudoantechinus macdonnellensis are predicted to be monandrous in their mating hehaviour. The monotremes (Ornithorhynchus anatinus, Tachyglossus aculeatus and Zaglossus bruijnii) are characterized by possession of very large testes; monotremes are shown to have significantly greater relative testes weights than marsupials, primates or avian species. This taxonomic difference is unlikely to be related 10 the occurrence of oviparity or to the abdominal position of the testes in the Monotremata. Their mating systems are not known in detail, but some evidence for multiple matings (and hence for sperm competition) exists for Tachyglossus aculeatus so that their large testes may be adaptive in this context.

1. 1. Body temperatures were determined by radio-telemetry in four male Tasmanian bettongs (Bettongia gaimardi) maintained for 72 hr at 20°C followed by 10 days in an outdoor enclosure. 2. 2. In both conditions Tb showed a diurnal rhythm in which Tmax coincided with greatest activity around midnight and tbasal (36.6°C) in laboratory animals) with sleep/rest around mid-day. 3. 3. Tbasal showed little variation between ambient temperatures of 5–30°C but increased at extremes on either side of this range; at 40°C Tbasal remained stable but at − 10°C continuous activity led to variable Tbasal.

The Tasmanian bettong (Bettongia gaimardi) is a small rat-kangaroo (marsupial) found only in Tasmania, Australia. The duration of pouch life is 15 weeks. Adults and older young display non-shivering thermogenesis and this paper examines the role of thyroxine in the development of endothermy in pouch young. Free thyroxine (T4) concentrations varied throughout pouch life. The mean (± SE) concentration was 6.2 ± 1.9 pmol L−1 in week 7, increased and peaked at 19.2 ± 4.3 pmol L−1 in week 12, and declined to 5.6 ± 0.4 pmol L−1 by week 20. This was similar to adult levels (3.2 ± 3.8 pmol L−1). These concentrations showed significant differences. From pouch week 12 onwards, T4 injection raised oxygen consumption. Maximum levels of VO2 after T4 injection occurred at weeks 14–15. Although adult levels were lower, the increase in adult oxygen consumption after T4 injection was about 50%. Peak free T4 levels and metabolic responses to nor-adrenalin occur at week 12 and we hypothesize that thyroid hormone may facilitate the development of adrenergic-receptors in this species. The data presented in the paper further attest to the likely important role of the thyroid gland in the development of endothermy in marsupial pouch young.

Microvascular dysfunction due to endothelial damage is often associated with the ionizing radiation used during cancer therapy. This radiation-induced capillary injury is a major factor in the inhibition of new vessel growth (angiogenesis) and in disease states such as radiation-induced pneumonitis and nephropathy. Many studies have examined the effects of radiation on endothelial cell function; however, little is known regarding the role the basement membrane plays in radiation-induced endothelial cell damage and angiogenesis. Therefore, we examined the effects of gamma radiation on aortic explants, and in vitro on three endothelial cell types (of artery, vein and capillary origin) irradiated with or without the basement membrane glycoprotein laminin-1. As expected, irradiation inhibited angiogenic sprouting of the aortic explants, endothelial cell proliferation, attachment, migration and differentiation in vitro in a dose-dependent manner. However, the effect of radiation on several of these processes in angiogenesis was reduced when the cells were irradiated on laminin-1. To further evaluate the effects of radiation on endothelial cells, we examined the expression of the vascular endothelial cell growth factor (VEGF) kinase domain region receptor in endothelial cells irradiated in the presence and absence of laminin-1. In endothelial cells irradiated on laminin-1, KDR expression increased 2.5-fold over control levels. Therefore, although radiation has a dose-dependent inhibitory effect on processes associated with angiogenesis in vitro, the presence of the basement membrane glycoprotein laminin-1 during irradiation decreases these effects.

Marsupials at birth are ectothermic and gradually attain the ability to change their metabolic heat production during pouch life. How this process occurs in the bettong has been measured on 13 pouch young from week 1 until 3 weeks after pouch vacation (week 18). Oxygen consumption was measured at 35 degrees C (pouch temperature) and at 22 degrees C. The results at 35 degrees C showed an increase in metabolic rate from week 1 until week 12 when there was a decrease to near adult levels after pouch vacation. At 22 degrees C young bettongs had a lower metabolic rate (compared with measurements made at 35 degrees C) until week 9 after which there was an increase above measurements made at 35 degrees C. Noradrenaline had little effect until week 10 after which the metabolic rate (although measured at 35 degrees C) paralleled the levels measured at 22 degrees C. The free thyroxine level was low in early pouch life, increased to a peak at week 12 then decreased. Thermal conductance increased until week 10 after which it decreased, reaching values similar to those of adult bettongs by week 20. The results indicate that non-shivering thermogenesis occurs in this macropodoid marsupial. This phenomenon may be a phylogenetic difference between macropodid and non-macropodid marsupials as also suggested by Nicol et al. (1997).

Angiogenesis, the formation of new vascular branches from pre-existing blood vessels, is closely linked to tumor growth and metastasis. The angiogenic process is characterized by the response of endothelial cells to a variety of stimulating factors. These cells, along with other cells comprising the vessel wall, initiate the process of angiogenesis by invading the basement membrane matrix to which they are attached, proliferating, adhering to extravascular matrix to migrate to a distal site, then differentiating and forming new vascular links. This process is required for all tumors to grow beyond 1 to 2 mm in diameter, and in response to low oxygen tension and reduced nutrients, tumor cells have the ability to release several growth factors that result in rapid expansion of the local vascular as well as the tumor cell mass (Folkman, 1992).

Basal body temperature, quantitative changes in vaginal smears and plasma concentrations of progesterone were measured during a number of oestrous cycles in Tasmanian bettongs (Bettongia gaimardi). These methods of monitoring the reproductive cycle were compared in an attempt to find a technique that allowed non-stressful assessment of the reproductive condition of the bettongs. Telemetric measurement of basal body temperature showed that there was a diurnal variation of 1.3 degrees C, typical of a nocturnal animal. During the oestrous cycle, there was a small, but not significant, peak in basal body temperature at oestrus (day 0) followed by a significant trough on day 2. There was a significant increase on day 3 and the temperature remained raised until day 10, during which time plasma progesterone concentrations are also high; the temperature then fell 2 days before oestrus. This fall corresponds to a decrease in concentration of plasma progesterone and in the numbers of leucocytes in vaginal smears. Telemetric measurement of body temperature may be useful as a non-stressful method of monitoring the oestrous cycle in bettongs.

Here we review the role of angiogenesis as it pertains to the interactions between the epithelium and the mesenchyme, especially during tumor growth and metastasis. We illustrate and discuss several models of angiogenesis including endothelial tube formation on Matrigel. Finally, we examine angiogenic factors using the Matrigel model and investigate several other matrix molecules for their importance in angiogenesis and epithelial/stromal interactions.

This study assessed whether capture and transferral into captivity represents a significant stressor to Tasmanian devils. Four male and four female devils were captured in the wild and housed for 6 months in captivity in male–female pairs. Blood samples were collected for cortisol assay at capture, every 24 h for the first 4 days, and then monthly; body weight and tail width were monitored weekly. In the males, mean plasma cortisol concentrations were highest (49 ± 9.19 ng mL–1) at the time of initial capture; cortisol concentrations declined significantly after 48 h in captivity (9.2 ± 5.96 ng mL–1) and did not change significantly over the months in captivity. Females exhibited a different pattern: plasma cortisol concentrations were highest (74.0 ± 3.24 ng mL–1) in the initial sample, but mean concentrations remained elevated in samples taken at 24, 48 and 96 h after initial capture, and did not exhibit a significant decline (to 20.65 ± 8.95 ng mL–1) until 4 weeks after capture. During the first 2 months in captivity, the male devils lost ~8.7% of their original body weight, and females lost 10.6% during this same period. However, body weights then rose during the rest of the experiment. These results suggest that Tasmanian devils experience elevated plasma cortisol concentrations in response to capture and transfer into captivity. However, these high concentrations are not maintained during 6 months in captivity, suggesting that the animals are not chronically stressed.

The energetics of the lesser long-eared bat, Nyctophilus geoffroyi, at the southern limits of its distribution was examined to determine whether this species shows any latitudinal variation in this aspect of its physiological ecology. Estimates of metabolic rate were obtained from the oxygen consumption of adult bats in a non-reproductive condition. Values for the thermoneutral zone were similar but thermal conductance was lower than for bats from mainland of Australia. Euthermic body temperature was higher (37.4 ± 0.2°C) and the ambient temperature at which N. geoffroyi entered torpor has a downward shift of 10°C at the southern limits of its distribution. The basal metabolic rate (1.12 ± 0.14 mL O2 g –1 h –1 ) also was lower than in lower latitudes. Thermal conductance of the bats in Tasmania was lower than that found in New South Wales or Western Australia (0.29 v. 0.38–0.39 mL O2 g –1 h –1 °C –1 ). All of these differences are apparently adaptations to a cooler environment. ZO en Ny l K. J o R

Many macropodids exhibit lactational quiescence during which an embryo produced at post-partum mating is retained as a blastocyst in utero while a pouch young is sucking. The sucking stimulus maintains secretion of prolactin which may in some species inhibit the activity of the corpus luteum and, hence, the development of the embryo. When the sucking frequency decreases, the blastocyst resumes development. In the present study, the dopamine agonist bromocriptine, which in many mammals results in decreased secretion of prolactin from the pituitary gland, was administered to the Tasmanian bettong (Bettongia gaimardi) at two different doses (12.5 mg kg(-1) and 5 mg kg(-1)). Although lactation was affected by both doses, as evidenced by slower growth of the pouch young or their loss, in only two cases did the quiescent blastocyst activate at the time of injection. This occurred with the highest dose of bromocriptine and was reflected by earlier changes in plasma progesterone concentrations. It is concluded that the Tasmanian bettong is unusual in its lack of sensitivity to bromocriptine.

The fetus of the marsupial Bettongia gaimardi, the Tasmanian bettong, has both morphological and cytological effects upon the gravid uterus. Development of diapausing embryos or the initiation of oestrous cycles was achieved by removal of the pouch young (RPY). Increases in the diameter of the uterine basal endometrial glands were noted 3 and 4 days later. An animal at Day 5 after RPY had glands in the gravid uterus that were significantly larger than those in the non-gravid uterus (P less than 0.01). This difference was also found in non-pregnant animals before Day 11 and was believed to be due to the local presence of the corpus luteum. Thereafter, significant differences were only found in pregnant animals until parturition at Day 17 or 18 after RPY. These differences were attributed to the local effect of the fetus and reflect a 'maternal recognition of pregnancy', as found in other macropodoid species.

1. Milk composition and energy content was measured in two related marsupials, Bettongia gaimardi and Potorous tridactylus. 2. Although protein content was consistently higher in bettong milk, lactational trends in both species are similar to those reported for other marsupials. 3. The faster relative growth rate of the bettong may be correlated with the increased protein and a higher milk intake.

Earlier workers suggest that marsupial embryonic growth rates are slower than those of many eutherians and that there is little correlation between marsupial gestation lengths and their weight at birth. Previously, this latter observation has been explained as being due to the considerable variability in duration of the initial slow phase of marsupial embryonic growth. The latter phase of pregnancy has always been regarded as rapid and highly uniform in all marsupials. However, this review shows that there can be considerable variation in growth rate during this ‘fast’ phase and also that marsupials have similar rates of embryonic growth to most eutherians. Development within the monotreme egg may proceed at a similar rate to intra-uterine growth in therian mammals.

Three different types of ectomycorrhizae found in the Southeastern United States on Eucalyptus nova-anglica and identified as being formed by Cenococcum geophilum, Pisolithus tinctorius, and Scleroderma geaster were examined with a scanning electron microscope (SEM). In overall appearance the three types of mycorrhizae could be distinguished easily from each other, particularly C. geophilum, which had a relatively smooth, undulate surface in comparison with the other two types. Detailed descriptions and comparisons of these ectomycorrhizae are given and the value of SEM in characterizing ectomycorrhizae is discussed

The selective toxic effects of cadmium on the testes of eutherian mammals have been well documented. A single subcutaneous or intraperitoneal injection of cadmium (as CdCl/sub 2/) results in testicular necrosis in most eutherian species. Some comparative work has also been carried out on other vertebrate groups, but studies of the effects of cadmium salts on the testes of non-eutherian mammals (monotremes and marsupials) are limited to two brief reports. The present paper reports the results following the injection of cadmium into another marsupial, the common Australian brush-tail possum (Trichosurus vulpecula). Sperm are found throughout the year in this species but breeding is mainly limited to the winter months with secondary peak in spring.

The growth cycle of the corpus luteum (CL) of the potoroo is similar to that of other macropodids. During delayed gestation, the post-partum CL remains quiescent until it is reactivated by removal of the sucking pouch young. The CL then undergoes a period of growth, rapid from Day 6 until Day 12, followed by a gradual decline from Day 21 to Day 27. Excision of the CL before Day 6 of pregnancy either inhibited embryonic development or failed to support it. Excision of the CL between 6 and 21 days after removal of pouch young did not prevent embryos developing to full term but interfered with parturition. Excision on Day 25 after removal of pouch young allowed birth but impaired lactation, neonates dying within 2 days. By Day 27, the CL appeared to be no longer essential for embryonic development, birth or neonate survival. It is suggested that the CL of the potoroo is required for a slightly greater proportion of pregnancy than in most larger kangaroos because the birth canal must be prepared before each parturition.

The reproductive biology of the Tasmanian Bettong (Bettongia gaimardi) conforms in many respects to that found in related kangaroos. Gestation and the oestrous cycle are of similar duration (21–22 days), and a postpartum oestrus may result in the formation of a blastocyst that remains quiescent (embryonic diapause) throughout most of pouch life. Oestrous cycles including a gestation are shorter (by 1·5 days) than those cycles without a pregnancy. This ‘maternal recognition of pregnancy’ is extended into pouch life as the furred young always vacates the pouch when a new young is born. Pouch life is relatively short (106 days) and, as the Bettong breeds throughout the year, several young may be reared/year. Both males and females become mature before one year.

The reproductive biology of Lampanyctodes hectoris (Gunther, 1876), Maurolicus muelleri (Gmelin, 1789) and Diaphus danae Taning, 1932, from continental-slope waters of eastern Tasmania, was examined between April 1984 and June 1985. L. hectoris spawned in winter and M. muelleri spawned from late winter to early summer. Apart from one ripe male, no reproductive activity was detected in D. danae; this species may be an expatriate in these waters. Fecundity was positively correlated with standard length in L. hectoris, but not in M. muelleri. The ratio of females to males increased with length in all three species. The spermatozoa of L. hectoris and D. danae are atypical of vertebrates and have no tail.

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Summary. An oestrous cycle length of 33 days (N = 4, range 32–34) was obtained for the common wombat from a number of parameters including vaginal smears, vaginal biopsies, changes in pouch morphology and behavioural observation. All but one of the successive periods of oestrus occurred during winter. Hourly measurements of body temperature by telemetry showed a rhythm typical of nocturnal species. Superimposed on this diurnal rhythm was another rhythm which could be correlated with the oestrous cycle.

1. The cutaneous water loss, respiratory rate and rectal temperature of the Tasmanian devil (Sarcophilus harrisi) was measured before and during heat stress. 2. There was a sevenfold increase in respiratory rate under heat stress indicating panting, whilst cutaneous water loss increased by only 50 per cent and remained below levels considered indicative of thermal sweating. 3. No marsupials are now known to use sweating as a thermoregulatory response when at rest. This response appears to be restricted to the primates and some ungulates.

In continuously breeding marsupials it is possible for successive young to occupy the pouch simultaneously. Although this rarely occurs in nature, it is most likely in some macropodids. Experiments by others have suggested that it is the pouch young which determines the duration of lactation and pouch occupancy. The female Bettongia gaimardi exhibits a precise sequence of events on the night her young vacates the pouch. Initially, the pouch muscle tightens, preventing re-entry by the large young, this is then followed by birth and/or oestrus. When pouch vacation is not followed by birth and/or oestrus, young have stayed in the pouch significantly longer. Experiments in which furred pouch young are replaced by others of different ages have shown that the replacements remain in the pouch until the night of birth and/or oestrus, regardless of their age. This indicates that in this species physiological events in the mother are at least partly responsible for determining the duration of pouch life.

Prenatal development of Macropus rufogriseus was described in eight stages ranging from a quiescent blastocyst to a near-term foetus. Embryos and corpora lutea were induced to resume development after diapause by the removal of suckling pouch young (RPY). The diameter of unilaminar blastocysts ranged from approximately 260 �m at 0 days after RPY to 290 �m after 6 days. At 9 days after RPY (330 �m diameter) the zona pellucida and mucoid coat were apparently absent and endoderm had proliferated (early bilaminar). At 15 days, mesoderm had formed in the trilaminar blastocyst (4.8 mm diameter). By 18 days after RPY the shell membrane had ruptured and was 3.0 �m in thickness (7.0 pm at 0 days after RPY). At this time the pre-foetal embryo had acquired forelimb ridges, mesonephric kidneys, optic stalks and 25 paired somites; persistent features included an amniopore, posterior neuropore and an intact stomodeal membrane; the lung buds and allantois were rudimentary; cervical, lumbosacral and cranial flexures were present. By 20 days after RPY, digital anlagen were noted in the forelimb paddles of the pre-foetal embryo (32 paired somites); the gonadal ridges; glomeruli and optic cups had formed. At 25 days after RPY, the near-term foetus had forelimbs with claws on the separate digits, hindlimb paddles, pontine flexure and cardiac valves; the metanephric kidneys, pigmented and nervous retinas and villous intestine were present. A single birth was recorded at 26 days after RPY (delayed gestation length).

The Tasmanian bettong, Bettongia gaimardi, appears to be the most common member of its genus. Though formerly distributed on the Australian mainland, B. gaimardi is now found only in the open forest habitats of eastern Tasmania, the vast majority of which are susceptible to forestry operations, such as clearfelling, burning and the laying of 1080 poison. Unless carefully managed, all of these practices in the long term are likely to reduce bettong populations. This and the fact that only 5% of bettong habitat lies within National Parks, leads to the conclusion that the conservation status of this species should be regarded as 'vulnerable'.

Milk samples from captive potoroos were analysed for composition during weeks 3-25 of the lactation period. During pouch residence, up to week 16, carbohydrate levels were high, ranging from 9 g 100 ml-1 at week 5 to 15 g 100 ml-1 at week 15; fat levels were consistently low, at around 2 g 100 ml-1; protein levels gradually increased from 5 g 100 ml-1 before week 10 to 12 g 100 ml-1 at week 16. Growth rates during this period increased exponentially, from 1 g week-1 at week 3 to 40 g week-1 at week 16. Thereafter, as the young left the pouch, marked changes were seen in carbohydrate and fat levels: by week 25, carbohydrate levels had fallen to 2 g 100 ml-1, and fat levels had risen to 26 g 100 ml-1. Protein levels increased moderately, reaching 15 g 100 ml-1 by week 25. Growth rates further increased during this period, to reach 60 g week-1 by week 25. Thus, trends in milk composition previously observed in Macropus species were observed also in the potoroo, suggesting a consistent pattern across the macropodid family. Carbohydrate levels in potoroo milk tend to be higher than in other macropodids, but total milk intake is as important as composition in determining growth rates.

The histological changes in the corpus luteum and uteri of P. tridactylus throughout delayed gestation are described. Early in gestation there appears to be a unilateral stimulus of the uterus ipsilateral to the corpus luteum. Late in gestation there appears to be a foeto-placental stimulus of the pregnant uterus. Embryonic development is closely associated with the uterine changes. At about day 29 after removal of pouch young the foetus is born via the median vagina. A model is proposed to explain the apparently great discrepancy between the length of delayed and undelayed gestation in this species.