Sutarostrongylus Johnsoni sp. n. (Nematoda: Trichostrongylina, Heligmosomoidea) from the pademelon, Thylogale stigmatica (Marsupialia) from Queensland, Australia

A new species of heligmosomoid nematode Sutarostrongylus johnsoni sp. n., belonging to the sub-family Herpetostrongylinae Skrjabin & Schultz, is described from the small intestine (duodenum) of the red-legged pademelon, Thylogale stigmatica (Gould, 1860) (Marsupialia: Macropodidae), from north-eastern Queensland, Australia. The only other species of the genus S. kirkpatricki Beveridge & Durelte-Desset, 1986 occurs in the related host, the red-necked pademelon, T. thetis (Lesson, 1827) in south-eastern Queensland. The new species differs in having longer spicules and asymmetrical spicule tips as well as the presence of a comarete which develops on the right ventral aspect of the mid-region of the body. The synlophe of the new species is unusual in that the inclination of the axis of orientation changes from being oblique in the anterior part of the body to being frontal in the posterior part. The same change may occur in some species of Austrostrongylus Chandler, 1924. Current data suggest that species of Sutarostrongylus are limited to a single genus of host, Thylogale Gray, 1837 and support the suggestion that both nematode species exhibit morphological features which are intermediate between those occurring in Herpetotostrongylinae in dasyurid marsupials and those occurring in macropodid marsupials.     

Corollonema thylogale n. g., n. sp. (Nematoda: Strongyloidea), parasitic in the pademelons Thylogale thetis and T. stigmatica (Marsupialia: Macropodidae) from Queensland, Australia

Corollonema thylogale n. g., n. sp. is described from the stomachs of Thylogale thetis and T. stigmatica from south-eastern Queensland. The new genus is characterised by four branches to the dorsal ray, a J-shaped ovejector, a cylindrical buccal capsule reduced to a posterior, thickened annulus and a leaf-crown of eight elements originating from the base of the buccal capsule. On the basis of these features, the new genus is placed in the subfamily Cloacininae Stossich, 1899 and the tribe Coronostrongylinea Beveridge, 1986. The presence of an internal leaf crown is unique within the tribe and the new genus is erected on this basis.     

Effects of historical forest contraction on the phylogeographic structure of Australo‐Papuan populations of the red‐legged pademelon (Macropodidae: Thylogale stigmatica)

Geographic patterns of genetic variation are strongly influenced by historical changes in species habitats. Whether such patterns are common to co‐distributed taxa may depend on the extent to which species vary in ecology and vagility. We investigated whether broad‐scale phylogeographic patterns common to a number of small‐bodied vertebrate and invertebrate species in eastern Australian forests were reflected in the population genetic structure of an Australo‐Papuan forest marsupial, the red‐legged pademelon (Macropodidae: Thylogale stigmatica). Strong genetic structuring of mtDNA haplotypes indicated the persistence of T. stigmatica populations across eastern Australia and southern New Guinea in Pleistocene refugial areas consistent with those inferred from studies of smaller, poorly dispersing species. However, there was limited divergence of haplotypes across two known historical barriers in the northeastern Wet Tropics (Black Mountain Barrier) and coastal mideastern Queensland (Burdekin Gap) regions. Lack of divergence across these barriers may reflect post‐glacial recolonization of forests from a large, central refugium in the Wet Tropics. Additionally, genetic structure is not consistent with the present delimitation of subspecies T. s. wilcoxi and T. s. stigmatica across the Burdekin Gap. Instead, the genetic division occurs further to the south in mideastern Queensland. Thus, while larger‐bodied marsupials such as T. stigmatica did persist in Pleistocene refugia common to a number of other forest‐restricted species, species‐specific local extinction and recolonization events have resulted in cryptic patterns of genetic variation. Our study demonstrates the importance of understanding individualistic responses to historical climate change in order to adequately conserve genetic diversity and the evolutionary potential of species.     

Helminth communities of pademelons, Thylogale stigmatica and T. thetis from eastern Australia and Papua New Guinea

Gastrointestinal helminths were collected from pademelons of the genus Thylogale (Marsupialia: Macropodidae) in eastern Australia and Papua New Guinea. Examined were 12 Thylogale stigmatica stigmatica and 13 T. s. wilcoxi, the latter subdivided into eight specimens from the northern limit of their distribution and five from southern areas, all from eastern Queensland, Australia, one T. s. oriomo from Papua New Guinea and ten T. thetis from southeastern Queensland and northern New South Wales, Australia. Six species of cestodes and 40 species of nematodes were found. The helminth community of T. s. stigmatica was similar to that found in northern specimens of T. s. wilcoxi, while differences from the helminth community present in southern T. s. wilcoxi could be accounted for by parasites acquired from sympatric T. thetis. Thylogale thetis harboured a community of helminths distinct from but related to that in T. stigmatica. The evidence suggests that all subspecies of T. stigmatica examined share a common helminth community, but that in areas of sympatry, T. stigmatica and T. thetis share some of their parasites.     

Rugonema labiatum n. g., n. sp. (Nematoda: Strongyloidea) from the stomach of Macropus irma (Marsupialia: Macropodidae) from Western Australia

Rugonema labiatum n. g., n. sp. is described from the stomach of Macropus irma (Jourdan) from Western Australia. The new genus possesses four branches to the dorsal ray, has a cylindrical buccal capsule and lacks a cervical groove, placing it within the subfamily Cloacininae Stossich, 1899. The presence of a prominently striated buccal capsule and labial as well as cephalic collars places the genus within the tribe Pharyngostrongylinea Popova, 1952, but it is distinguished from all existing genera within the tribe by the possession of four lips. The presence of lips is an important characteristic of the related tribe Zoniolaiminea (Popova, 1952) and the characters used in distinguishing these two tribes are discussed.     

Electrophoretic comparison of Rugopharynx longibursaris Kung and R. omega Beveridge (Nematoda: Strongyloidea), with the description of R. sigma n. sp. from pademelons,Thylogale spp. (Marsupialia: Macropodidae)

An electrophoretic comparison of the nematodes Rugopharynx longibursaris and R. omega, both from Macropus rufogriseus in south-eastern Australia, revealed fixed genetic differences at 4.5% of the 23 enzyme loci examined. The electrophoretic data do not therefore reject the null hypothesis that the two taxa are conspecific. R. longibursaris was found in Tasmania and in the western mainland population of M. rufogriseus, while R. omega occurred only in the eastern mainland population. Implications for the taxonomic status of the western host population are considered. Specimens formerly assigned to R. omega, from Thylogale stigmatica from Queensland, were found to differ at 45.0% of enzyme loci from specimens from M. rufogriseus. Morphological examination revealed differences in the shape of the buccal capsule, the position of the deirid, the morphology of the spicule tip and the presence of a gubernaculum. A new species, R. sigma, is erected for specimens from T. stigmatica, T. thetis and T. calabyi.     

Progamotaenia capricorniensis sp. nov. (Cestoda: Anoplocephalidae) from wallabies (Marsupialia: Macropodidae) from Queensland, Australia

Progamotaenia capricorniensis sp. nov. (Cestoda: Anoplocephalidae) is described from the wallabies Macropus dorsalis (Gray, 1837) and Petrogale assimilis Ramsay, 1877 from Queensland, Australia. The new species is characterised by a fimbriated velum composed of 26-32 digitiform to triangular projections on each side of the proglottis, paired uteri and 140-190 testes distributed in a single band across the medulla. Minor variation occurs in the distribution of the testes. The above characters distinguish the new species from its most closely related congeners P. lagorchestis (Lewis, 1914), P. proterogyna (Fuhrmann, 1932), P. spearei Beveridge, 1980 and P. villosa (Lewis, 1914). P. capricorniensis appears to exhibit a highly disjunct distribution within its usual host, M. dorsalis.     

Foraging in a risky environment: a comparison of Bennett's wallabies Macropus rufogriseus rufogriseus (Marsupialia: Macropodidae) and red‐bellied pademelons Thylogale billiardierii (Marsupialia: Macropodidae) in open habitats

Abstract This study aimed to establish whether red‐bellied pademelons (Thylogale billiardierii) and Bennett's wallabies (Macropus rufogriseus rufogriseus) alter their foraging distribution in open habitat, in response to food availability and distance to protective shelter, the latter used as a measure of predation risk. Scat counts were used as a measure of the presence or absence of these macropods over two plantations (Russell and Dunalley). These plantations differed in both their on‐site food and shelter characteristics (the presence or absence of windrows). Logistic regression indicated that at Russell, which had low food availability but the presence of on‐site shelter, probability of scats of both species increased with the percentage cover of both edible and inedible vegetation. The probability of both pademelon and wallaby scats decreased with increasing distance from windrows, but increased with increasing distance from forest at the plantation edge. Logistic regression indicated that at Dunalley, which had high food availability but no on‐site shelter, the probability of scats of both species increased with an increase in the percentage cover of edible vegetation. In relation to predation risk, however, the two species differed in their response. Pademelons exhibited a decrease in scat probability with increasing distance from the forest at the plantation edge, while wallabies showed an increase in scat probability with distance from the forest at the plantation edge. Results indicated some differences in antipredation strategies of the two species, which may be a function of differences in body size.     

The anoplocephalid cestode parasites of the spectacled hare-wallaby Lagorchestes conspicillatus Gould, 1842 (Marsupialia: Macropodidae).

Progamotaenia gynandrolinearis sp. nov. is described from the small intestine of Lagorchestes conspicillatus Gould, 1842 from Barrow I., Western Australia. It is distinguished from other species by the small number of testes arranged in a single transverse row. Progamotaenia lagorchestis (Lewis, 1914) is redescribed. The name Progamotaenia thylogale sp. nov. is proposed for a second species described previously under the name P. lagorchestis. Progamotaenia zschokkei (Janicki, 1905), Progamotaenia festiva (Rudolphi, 1819) and Progamotaenia villosa (Lewis, 1914) were also found in L. conspicillatus.     

Macropostrongyloides dendrolagi n. sp. and Mbaisonema coronatum n. g., n. sp., two new species of nematodes (Strongyloidea: Cloacinidae) from tree-kangaroos,Dendrolagus spp. (Marsupialia: Macropodidae) from Irian Jaya,Indonesia

Two new species of strongyloid nematodes are described from tree-kangaroos, Dendrolagus spp. (Marsupialia: Macropodidae), from Irian Jaya, Indonesia. Macropostrongyloides dendrolagi n. sp. from the colon of Dendrolagus dorianus (type-host) and D. mbaiso is distinguished from congeners by the presence of a cephalic inflation and paired lateral alae which extend along the body from the cephalic inflation. Mbaisonema coronatum n. g., n. sp., from the stomach of D. mbaiso, is allocated to the tribe Coronostrongylinea Beveridge, 1986, as the buccal capsule is reduced to a sclerotised annulus and the lining is inflated into lip-like lobes at the anterior extremity. The new genus is allied to Popovastrongylus Mawson, 1977, from which it is distinguished by the presence of a labial crown composed of numerous elements.     

Comparative red blood cell metabolism in three wallaby species, Macropus eugenii, Macropus parma and Thylogale thetis (Macropodidae: Marsupialia)

Aspects of red blood cell metabolism were compared among three species of small macropodid marsupials from different habitats. Packed cell volume (PCV), erythrocyte reduced glutathione (GSH) concentration and GSH regeneration rates were similar in all three species. The Parma wallaby had very low red cell potassium levels compared to the other species studied. The Tammar wallaby had higher rates of glucose consumption and lactate production in vitro at both pH 7.4 and 8.2 than did the Parma and significantly lower adenosine triphosphate (ATP) levels than the other species. These findings are consistent with preliminary reports published previously. The differences noted cannot be directly related to differences in the habitats of the species.     

Phylogenetic relationships of rock-wallabies, Petrogale (Marsupialia: Macropodidae) and their biogeographic history within Australia

The rock-wallaby genus Petrogale comprises a group of habitat-specialist macropodids endemic to Australia. Their restriction to rocky outcrops, with infrequent interpopulation dispersal, has been suggested as the cause of their recent and rapid diversification. Molecular phylogenetic relationships within and among species of Petrogale were analysed using mitochondrial (cytochrome oxidase c subunit 1, cytochrome b, NADH dehydrogenase subunit 2) and nuclear (omega-globin intron, breast and ovarian cancer susceptibility gene) sequence data with representatives that encompassed the morphological and chromosomal variation within the genus, including for the first time both Petrogale concinna and Petrogale purpureicollis. Four distinct lineages were identified, (1) the brachyotis group, (2) Petrogale persephone, (3) Petrogalexanthopus and (4) the lateralis-penicillata group. Three of these lineages include taxa with the ancestral karyotype (2n=22). Paraphyletic relationships within the brachyotis group indicate the need for a focused phylogeographic study. There was support for P. purpureicollis being reinstated as a full species and P. concinna being placed within Petrogale rather than in the monotypic genus Peradorcas. Bayesian analyses of divergence times suggest that episodes of diversification commenced in the late Miocene-Pliocene and continued throughout the Pleistocene. Ancestral state reconstructions suggest that Petrogale originated in a mesic environment and dispersed into more arid environments, events that correlate with the timing of radiations in other arid zone vertebrate taxa across Australia.     

Species of Cloacina Linstow, 1898 (Nematoda: Strongyloidea) from the black-tailed wallaby, Wallabia bicolor (Desmarest, 1804) from eastern Australia

Species of Cloacina Linstow, 1898 (Nematoda: Strongyloidea) are reported and/or described from the stomach of the macropodid marsupial Wallabia bicolor (Desmarest, 1804) collected in eastern Australia. Nematodes were examined from 26 hosts collected in 3 states and the number of species of Cloacina in any one host was 2--7. The following species were encountered: C. wallabiae Johnston and Mawson, 1939, C. gallardi Johnston and Mawson, 1940, C. edwardsi Mawson, 1972 and C. cornuta (Davey and Wood, 1938) the last named constituting a new host record. The following new species are described: C. mawsonae sp. nov., C. papillata sp. nov., C. annulata sp. nov., C. castor sp. nov. and C. pollux sp. nov.     

Phylogeography of the pademelons (Marsupialia: Macropodidae: Thylogale) in New Guinea reflects both geological and climatic events during the Plio‐Pleistocene

Aim Alternative hypotheses concerning genetic structuring of the widespread endemic New Guinean forest pademelons (Thylogale) based on current taxonomy and zoogeography (northern, southern and montane species groupings) and preliminary genetic findings (western and eastern regional groupings) are investigated using mitochondrial sequence data. We examine the relationship between the observed phylogeographical structure and known or inferred geological and historical environmental change during the late Tertiary and Quaternary. Location New Guinea and associated islands. Methods We used primarily museum specimen collections to sample representatives from Thylogale populations across New Guinea and three associated islands. Mitochondrial cytochrome b and control region sequence data were used to construct phylogenies and estimate the timing of population divergence. Results Phylogenetic analyses indicated subdivision of pademelons into ‘eastern’ and ‘western’ regional clades. This was largely due to the genetic distinctiveness of north‐eastern and eastern peninsula populations, as the ‘western’ clade included samples from the northern, southern and central regions of New Guinea. Two tested island groups were closely related to populations north of the Central Cordillera; low genetic differentiation of pademelon populations between north‐eastern New Guinea and islands of the Bismarck Archipelago is consistent with late Pleistocene human‐mediated translocations, while the Aru Islands population showed divergence consistent with cessation of gene flow in the mid Pleistocene. There was relatively limited genetic divergence between currently geographically isolated populations in subalpine and nearby mid‐montane or lowland regions. Main conclusions Phylogeographical structuring does not conform to zoogeographical expectations of a north/south division across the cordillera, nor to current species designations, for this generalist forest species complex. Instead, the observed genetic structuring of Thylogale populations has probably been influenced by geological changes and Pleistocene climatic changes, in particular the recent uplift of the north‐eastern Huon Peninsula and the lowering of tree lines during glacial periods. Low sea levels during glacial maxima also allowed gene flow between the continental Aru Island group and New Guinea. More work is needed, particularly multi‐taxon comparative studies, to further develop and test phylogeographical hypotheses in New Guinea.     

A morphological and electrophoretic study of Rugopharynx zeta (Johnston & Mawson, 1939) (Nematoda: Strongyloidea), with the description of a new species,R. mawsonae,from the black-striped wallaby Macropus dorsalis (Marsupialia: Macropodidae)

Rugopharynx zeta (Johnston & Mawson) (Nematoda: Strongyloidea) is redescribed from the rock wallabies Petrogale penicillata penicillata, P. p. herberti, P. inornata and P. assimilis from Queensland and New South Wales, Australia. Specimens formerly assigned to this nematode taxon from the wallabies Macropus dorsalis and M. parma are treated as a new species, R. mawsonae. R. mawsonae n. sp. differs from R. zeta in the shape of the dorsal ray, length of spicules, morphology of spicule tip, length of female tail and position of deirid. The morphological differences are supported by electrophoretic data. R. zeta and R. mawsonae n. sp. had fixed genetic differences at 45.0% of the 21 enzyme loci examined, while each differed at 38.1% and 45.0% of loci respectively from the morphologically distinct R. delta (Johnston & Mawson). The known host and geographical distributions of R. zeta and R. mawsonae n. sp. are reviewed.     

Mate Choice in Female Red-necked Pademelons,Thylogale thetis (Marsupialia: Macropodoidea)

Changes in the behaviour of captive female red-necked pademelons, Thylogale thetis, before, during and after oestrus were observed relative to the location of potential male mates. A penned female was presented with four adjacent, individually caged males representing the size classes large, medium, small and subadult. The female's behaviour was videotaped for 8–9 d spanning oestrous (3 d), post-oestrous (3 d) and normal (3 d) sessions of time. Changes in the activity, orientation and location of six penned females, relative to the caged males, were transcribed from videotape. A model of female pademelon behaviour pattern was developed. Results suggest that the females spent a significantly greater amount of time directly in front of the largest available male, relative to the other three smaller males during the oestrous period only, and that a significant proportion of this time was spent involved in active behaviours (grooming and locomotion, compared with inactive behaviours of sitting and scan/sniffing). Although there was a significant preference for females to orientate their bodies away from the location of the males, they faced the males significantly more during oestrus than any other session. Furthermore, the females faced the large male significantly more frequently than any other male. This study provides evidence for mate choice by female red-necked pademelons.