Resolution of portions of the kangaroo phylogeny (Marsupialia: Macropodidae) using DNA hybridization

We generated a DNA hybridization matrix comparing eleven 'true' kangaroos (Macropodinae) and two outgroup marsupials, the rufous rat-kangaroo Aepyprymnus rufescens (Potoroinae) and the brush-tailed phalanger Trichosurus vulpecula (Phalangeridae). A small matrix included additional species of the genus Macropus (large kangaroos and wallabies). The results indicate that the New Guinean forest wallaby Dorcopsulus vanheurni, and the quokka Setonix brachyurus, represent successively closer sister-groups of other macropodines. The remaining taxa examined form two clades: the tree kangaroo Dendrolagus matschiei with die pademelons Thylogale and rock wallabies Petrogale, and Macropus including the swamp wallaby Wallabia bicolor. The smaller matrix of five Macropus species and Wallabia (with Dorcopsulus as an outgroup) pairs the red-necked wallaby M. rufogriseus and Parry's wallaby M. parryi, with the eastern grey kangaroo M. giganteus as their nearest relative; and associates the red kangaroo M. rufus and wallaroo M. robustus, with Wallabia as their sister-taxon. In the larger study, we found mat inclusion of both outgroups provided little resolution among the macropodines, judging by jackknife and bootstrap tests. When Aepyprymnus was deleted, the Dendrolagus-Thylogale-Petrogale association obtained; with Trichosurus eliminated instead, the Wallabia-Macropus group was recovered. Only analysis of the eleven ingroup taxa by themselves gave a topology which supported both major clades. Our findings suggest that, at least for DNA hybridization studies, when ingroup taxa are separated by very short internodes experimental error in outgroup-to-ingroup distances may seriously compromise determination of ingroup affinities as well as the position of the root. We recommend that in such cases separate analyses with the outgroups sequentially eliminated and rigorous validation of die topology at each step should be conducted.     

Review of Papillostrongylus Johnston & Mawson, 1939 (Nematoda: Strongyloidea) from wallabies and kangaroos (Marsupialia: Macropodidae) using morphological and molecular techniques,with the description of P. barbatus n. sp.

The strongyloid nematode genus Papillostrongylus Johnston & Mawson, 1939, from kangaroos and wallabies, is reviewed using morphological and molecular methods. P. labiatus Johnston & Mawson, 1939 is re-described from material from the type-host, the black-striped wallaby Macropus dorsalis, from eastern Queensland, Australia, in which it is a relatively common parasite. Additional records from M. parryi and Thylogale thetis are confirmed and considered to represent examples of host-switching. A geographically disjunct population of the nematode species occurs in M. bernardus and Petrogale brachyotis in Arnhem Land, Northern Territory, but assessment of its status requires additional material. Nematodes from M. rufus, M. giganteus, M. fuliginosus and M. robustus from inland regions of Australia, formerly attributed to P. labiatus, are here assigned to a new species, P. barbatus, distinguished by the presence of an external leaf-crown, larger size, by greater spicule length in the male and by a sinuous vagina in the female. Additional hosts of P. barbatus n. sp. are Petrogale assimilis and Pet. lateralis purpureicollis. Sequence analyses of the second internal transcribed spacer of ribosomal DNA (ITS-2) also showed that P. barbatus n. sp. differed at 40 (16.7%) of the 240 alignment positions when compared with P. labiatus. Most of these interspecific sequence differences occurred in loops or bulges of the predicted precursor rRNA secondary structure, or represented partial or total compenstory base pair changes in stems.     

Pinning down a polymorphic parasite: new genetic and morphological descriptions of Eimeria macropodis from the Tammar wallaby (Macropus eugenii)

Identification of the protozoan parasite, Eimeria has traditionally relied on oocyst morphology, host range and life-cycle attributes. However, it is increasingly recognized that Eimeria species can vary in size and shape across their host range, an attribute known as 'polymorphism' that presents a unique challenge for identification. Advances in molecular tools hold promise for characterising Eimeria that may otherwise be misclassified based on morphology. Our study used morphologic and molecular traits of the oocyst life stage to identify a polymorphic parasite, Eimeria macropodis in a captive Tammar wallaby (Macropus eugenii) population in Australia. Molecular characterization highlighted the need to use multiple genetic markers (18S SSU and cytochrome c oxidase subunit I) to accurately identify E. macropodis owing to heterozygous alleles at the 18S SSU locus. This study provided an opportunity to assess the utility and shortcomings of morphologic and molecular techniques for 'pinning down' a polymorphic species. Moreover, our study was able to place E. macropodis in an evolutionary context and enhance resolution of the under-studied marsupial clade.     

Molecular characterization of Eimeria species in macropods

A total of 597 faecal samples were collected from western grey kangaroos (Macropus fuliginosus), Euros (M. robustus), red kangaroos (M. rufus) in Western Australia and Eastern Grey Kangaroos (M. giganteus) from Victoria and screened for the presence of Eimeria by PCR at the 18S ribosomal RNA (rRNA) locus. The overall prevalence was 24.3% (145/597). At the 18S rRNA locus, sequences were obtained for 25 of the 145 positives. Phylogenetic analysis indicated that all the macropod-derived Eimeria species grouped in a separate marsupial clade that included Eimeria trichosuri from brushtail possums. At least 6 different clades were identified within the marsupial isolates and many of the genotypes identified are likely to be valid species, however morphological and biological data need to be collected to match sequences to previously characterized Eimeria species or identify if they are new species.     

Climatological correlates for body size of five species of Australian mammals

Size variation of body and skull of five species of Australian mammals (echidna, Tachyglossus aculeatus ; brush-tail possum, Trichosurus vulpecula ; eastern grey kangaroo, Macropus giganteus ; western grey kangaroo, M. fuliginosus ; red kangaroo, M. rufus ), is related to climatic factors. All five species show trends in body size that conform with Bergmann's rule, individuals from colder environments being larger than those from warmer areas. The western and eastern grey kangaroos also conform with Allen's rule, the relative size of their extremities being large in warmer areas. In four of the five species (not the red kangaroo) body size is also correlated with indices of biomass productivity. However, since biomass productivity and ambient temperature are related to some extent, it is difficult to separate the effects of these factors.     

Free-ranging heart rate, body temperature and energy metabolism in eastern grey kangaroos (Macropus giganteus) and red kangaroos (Macropus rufus) in the arid regions of South East Australia

Eastern grey kangaroos (Macropus giganteus) are generally regarded as mesic inhabitants. Even though access to drinking water in permanent stock watering troughs is commonly available, these animals are still found in only low densities in arid pastoral areas. We hypothesised that the differential success of red and grey kangaroos in the arid zone may be due to higher energy requirements of M. giganteus with a concomitant need for increased food, rather than limitations imposed by inadequate water access. We set out to test this by indirectly measuring energy expenditure through the monitoring of heart rate by radio telemetry in semi-free-ranging eastern grey and red kangaroos (Macropus rufus). Radio telemetry measurements of heart rate were calibrated against oxygen consumption and were used in the assessment of energy expenditure of animals maintained in an 8-ha enclosure in the arid zone of southeast Australia. Heart rate provided a reliable estimate of oxygen consumption. This well-correlated relationship was curvilinear and was established for each individual. Behavioural observations revealed that both kangaroo species spent most of the day in low energy demanding activities. M. rufus were more active at night whilst M. giganteus were more active in the early mornings and late afternoons. Like other marsupials, both species had low field metabolic rates (FMRs). However, M. giganteus in keeping with their mesic history had higher FMRs than the more arid-adapted M. rufus, particularly during water restriction. Body temperature telemeters revealed a further species difference in that under hot conditions when water is freely available, M. rufus exhibits a higher and more labile daytime body temperature than M. giganteus. During the hottest part of the day M. giganteus maintain body temperature, relying upon increased evaporative cooling mechanisms, such as licking. Indeed, only when access to drinking water was restricted was thermolability evident in M. giganteus. Differences in behaviour and concomitant energy expenditure may thus contribute substantially to the divergent distribution and abundance of these two kangaroo species.     

Progamotaenia ruficola sp. n. (Cestoda: Anoplocephalidae) from the red kangaroo, Macropus rufus (Marsupialia)

Progamotaenia ruficola sp. n. is described from the red kangaroo (Macropus rufus) from New South Wales, Australia. It is distinguished from other similar species having paired, nondiverticulate uteri in each prolottis: Progamotaenia festiva (Rudolphi 1819), P. diaphana (Zschokke 1907), and P. macropodis Beveridge 1976, by the extremely broad, straight-edged velum, the lack of an external seminal vesicle, the cirrus armature, the number of testes, the lack of vaginal atrophy following insemination, and the morphology of the egg.     

A New Family of Entodiniomorph Protozoa from the Marsupial Forestomach, with Descriptions of a New Genus and Five New Species

ABSTRACT. A unique group of entodiniomorph protozoa was found in forestomach contents from quokka ( Setonix brachyurus ), western grey kangaroo ( Macropus fuliginosus ), red kangaroo ( Macropus rufus ) and euro ( Macropus robustus erubescens ). A new genus, Macropodinium n.g., containing five new species, is described. Three species are described from forestomach contents of the quokka: Macropodinium baldense n. sp., Macropodinium moiri n. sp. and Macropodinium setonixum n. sp. A single species, Macropodinium ennuensis n. sp., is described from the red kangaroo and euro. The last species, Macropodinium yalanbense n. sp., is described in forestomach contents from the western grey kangaroo. At least three distinct features in the new genus are incompatible with any of the described families in the order Entodiniomorphida. On this basis, the new family Macropodiniidae has been created.     

"Whey" proteins of milk of the red (Macropus rufus) and eastern grey (Macropus giganteus) kangaroo

1. A comparison is made of gel electrophoretic patterns of the "whey" proteins of the milk of red (Macropus rufus) and eastern grey (Macropus giganteus) kangaroos at various stages of lactation. Qualitative and quantitative changes occur with time during the mature phase of lactation of both types. Their onset is related solely to the stage of lactation. "Whey" proteins are isolated and characterised and the nature of protein changes determined for the first time. 2. The anodic electrophoretic pattern is divided into 6 main zones (designated A F in order of decreasing mobility) and 2 cathodic zones (G and H) that are only detected in the milk of M. giganteus. 3. Zones A, B and C are milk specific. Zone B is present throughout lactation in both species and is an alpha-lactalbumin. Zones A and C are present only in late lactation, zone C, usually, but not always, appearing first. Zone A is an alpha-lactalbumin in M. giganteus, but is not an alpha-lactalbumin in M. rufus. Zone C appears to be the same protein in both species and is possibly a beta-lactoglobulin. 4. Zone D is kangaroo serum albumin and zone E is possibly a beta 2-microglobulin. Zone F contains three main iron (III) binding bands whose relative intensity varies with stage of lactation. Their intensity differs from the corresponding blood serum transferrin bands. 5. Zone H of Macropus giganteus is a lysozyme. 6. Lactose is present in the milk, but is not the principal sugar. 7. The significance of the results is discussed.     

Provisional mapping of the gene for a cell surface marker, GA-1, in the red-necked wallaby Macropus rufogriseus

A series of M. rufogriseus-mouse somatic cell hybrids was constructed and analysed cytologically, enzymatically and immunologically. A monoclonal antibody, GA-1, was prepared against an M. rufogriseus cell surface antigen on an M. rufogriseus-mouse somatic cell hybrid. A gene determining the expression of this antigen was provisionally assigned to the long arm of the M. rufogriseus chromosome 3. The monoclonal antibody also reacted with an M. rufus (red kangaroo)-mouse somatic cell hybrid containing only the M. rufus chromosome 5, the G-banded chromosome identical to M. rufogriseus 3q. The results also suggest synteny of the genes for the marsupial enzymes hypoxanthine phosphoribosyltransferase and phosphoglycerate kinase-A.     

Ventilatory accommodation of oxygen demand and respiratory water loss in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus)

We studied ventilation in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus), respectively, within the range of ambient temperatures (T(a)) from -5 degrees to 45 degrees C. At thermoneutral temperatures (Ta=25 degrees C), there were no differences between the species in respiratory frequency, tidal volume, total ventilation, or oxygen extraction. The ventilatory patterns of the kangaroos were markedly different from those predicted from the allometric equation derived for placentals. The kangaroos had low respiratory frequencies and higher tidal volumes, even when adjustment was made for their lower basal metabolism. At Ta>25 degrees C, ventilation was increased in the kangaroos to facilitate respiratory water loss, with percent oxygen extraction being markedly lowered. Ventilation was via the nares; the mouth was closed. Differences in ventilation between the two species occurred at higher temperatures, and at 45 degrees C were associated with differences in respiratory evaporative heat loss, with that of M. giganteus being higher. Panting in kangaroos occurred as a graded increase in respiratory frequency, during which tidal volume was lowered. When panting, the desert red kangaroo had larger tidal volumes and lower respiratory frequencies at equivalent T(a) than the eastern grey kangaroo, which generally inhabits mesic forests. The inference made from this pattern is that the red kangaroo has the potential to increase respiratory evaporative heat loss to a greater level.     

Lack of evidence for co-speciation in a parasitic nematode of grey kangaroos

Multilocus enzyme electrophoresis was used to compare specimens of the parasitic nematode Cloacina obtusa from the stomach of the eastern grey kangaroo, Macropus giganteus and the western grey kangaroo, M. fuliginosus. Allelic variation among nematodes was detected at 17 (85%) of 20 loci, but there was only a single fixed genetic difference (at the locus for isocitrate dehydrogenase, IDH) between C. obtusa from M. fuliginosus and those from M. giganteus in areas where each host occurred in allopatry. However, this fixed difference was not apparent within the zone of host sympatry. Although electrophoretic data indicate genetic divergence among allopatric populations of C. obtusa in the two host species, the magnitude of the electrophoretic difference (5%) between these populations does not refute the hypothesis that C. obtusa represents a single species. The 'usual' situation for parasitic helminths of grey kangaroos is that pairs of parasite species occur in the two host species. This situation differs for C. obtusa, where there has been a lack of speciation following a speciation event in its macropodid marsupial hosts. This finding suggests that a speciation event in the host does not necessarily lead to a speciation event for all its parasites and further highlights our lack of understanding of which processes drive speciation in parasites.     

Australia's savanna herbivores: bioclimatic distributions and an assessment of the potential impact of regional climate change

The future impacts of climate change are predicted to significantly affect the survival of many species. Recent studies indicate that even species that are relatively mobile and/or have large geographic ranges may be at risk of range contractions or extinction. An ecologically and evolutionary significant group of mammals that has been largely overlooked in this research is Australia's large marsupial herbivores, the macropodids (kangaroos). The aims of our investigation were to define and compare the climatic conditions that influence the current distributions of four sympatric large macropodids in northern Australia (Macropus antilopinus, Macropus robustus, Macropus giganteus, and Macropus rufus) and to predict the potential future impact of climate change on these species. Our results suggest that contemporary distributions of these large macropodids are associated with well-defined climatic gradients (tropical and temperate conditions) and that climatic seasonality is also important. Bioclimatic modeling predicted an average reduction in northern Australian macropodid distributions of 48% +/- 16.4% in response to increases of 2.0 degrees C. At this temperature, the distribution of M. antilopinus was reduced by 89% +/-0.4%. We predict that increases of 6.0 degrees C may cause severe range reductions for all four macropodids (96% +/-2.1%) in northern Australia, and this range reduction may result in the extinction of M. antilopinus.     

Description of a new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from the western Derby eland Taurotragus derbianus derbianus Gray (Artiodactyla: Bovidae) in Senegal

Examination of faecal samples from semi-captive western Derby elands Taurotragus derbianus derbianus Gray, in the Bandia and Fathala Reserves of Senegal, revealed the presence of o?cysts of the genus Eimeria Schneider, 1875 that we considered to represent a new species, Eimeria derbiani n. sp. The new species possesses nearly ellipsoidal o?cysts (length/width ratio 1.3) with a bi-layered wall and an average size of 27.6 × 21.5 μm. E. derbiani possesses a micropyle covered by a micropylar cap and ovoidal, single-layered sporocysts with an average size of 14.9 × 7.7 μm, each with a Stieda body. Sporozoites of E. derbiani possess a large refractile body and a nucleus. Sporulation lasted for 2 days at 23°C. The new species is differentiated from the two species parasitising Taurotragus oryx Pallas, E. canna Triffitt, 1924 and E. triffittae Yakimoff, 1934.     

Coccidia (Apicomplexa: Eimeriidae) from sciurid rodents (Eutamias, Sciurus, Tamiasciurus spp.) from the western United States and northern Mexico with description of two new species

Since May 1979, 190 rodents in the family Sciuridae, representing three genera and nine species, have been collected in the western United States and northern Mexico and examined for coccidia; 71 (37%) had coccidian oocysts in their feces. These included 2 of 12 (17%) Eutamias canipes; 7 of 12 (58%) E. dorsalis; 18 of 50 (36%) E. merriami; 33 of 96 (34%) E. obscurus; 3 of 4 (75%) E. townsendii; 3 of 9 (33%) Sciurus aberti; 1 of 1 S. griseus; 1 of 1 Tamiasciurus hudsonicus mogollonensis; and 3 of 5 (60%) T. mearnsi. The following coccidians were identified from infected rodents: Eimeria cochisensis n. sp. and Eimeria dorsalis n. sp. from E. canipes, E. cochisensis, E. dorsalis, and E. tamiasciuri from E. dorsalis, E. dorsalis and E. tamiasciuri from E. merriami; E. cochisensis, E. dorsalis, E. tamiasciuri, and E. wisconsinensis from E. obscurus; E. cochisensis and E. dorsalis from E. townsendii; E. ontarioensis and E. tamiasciuri from S. aberti; E. tamiasciuri from S. griseus; E. tamiasciuri and E. toddi from T. h. mogollonensis; and E. tamiasciuri from T. mearnsi. Sporulated oocysts of Eimeria dorsalis n. sp. were ovoid, 21.9 x 16.8 (17-24 x 14-20) micrometer with sporocysts ovoid, 11.5 x 6.9 (10-14 x 6-8) micrometer. Sporulated oocysts of Eimeria cochisensis n. sp. were spheroid to subspheroid, 16.7 x 15.3 (15-18 x 14-17) micrometer, with sporocysts ovoid, 8.4 x 5.6 (6-11 x 4-7) micrometer. Fifty-five of 71 (77%) infected hosts had oocysts of only one eimerian species in their feces at the time they were examined. One eimerian, E. tamiasciuri, was found in seven of nine host species in three genera. A list is provided of all eimerians (22, including the species described here) that have been described in the literature from Eutamias, Sciurus, and Tamiasciurus spp.     

Repertoires of social behaviour in captive and free-ranging grey kangaroos, Macropus giganteus and Macropus fuliginosus (Marsupialia: Macropodidae)

The eastern grey kangaroo, Macropus giganteus , and the western grey kangaroo, M. fuliginosus , are sibling species. The behaviour of 48 eastern grey kangaroos and 15 western grey kangaroos was observed for 249 h at Melbourne Zoo. Up to 31 eastern grey kangaroos and 38 western grey kangaroos were observed for 305 h where they occurred syntopically in the Grampians National Park.
In total, 46 social acts were identified in four social contexts between conspecifics. All but one of the acts were performed by both species in captivity, whereas fewer were seen performed by either species in the field. Five general acts were performed by all age/sex classes, and 10 acts occurred in mother-young contexts. High-intensity agonistic acts and all sexual acts were performed exclusively by adult males. In captivity, western grey males performed a truncated range of sexual acts directed at eastern grey females, but no interspecific sexual acts were performed by males of either species in the field, supporting the distinctiveness of the two species. The close evolutionary relationship between the two species was confirmed by high degree of concordance between their behavioural repertories, which differed only in the structure of the isolation call given by large pouch young.     

Genetic evidence for a complex of species within Rugopharynx australis (Mönnig, 1926) (Nematoda: Stronglyloidea) from macropodid marsupials

An electrophoretic analysis using 17 enzyme loci was carried out on specimens of the gastric nematode of macropodid marsupials, Rugopharynx australis (Mönnig, 1926), collected from Macropus eugenii (Desmarest), M. fuliginosus (Desmarest), M. giganteus Shaw, M. robustus Gould, M. rufogriseus (Desmarest), M. rufus (Desmarest), Thylogale billardierii (Desmarest) and Wallabia bicolor (Desmarest) from south-eastern Australia. The extent of fixed genetic differences between nematodes from different host species ranged from 0–53%. The two distinct morphological forms of the parasite found in M. rufogriseus differed at 50% of loci. Specimens present in M. fuliginosus and M. giganteus were indistinguishable genetically, as were nematodes from M. rufus and M. robustus. Of the two morphologically distinct congeners included in the analysis as controls, Rugopharynx epsilon (Johnston & Mawson, 1939) was genetically distinct (46–69% fixed genetic differences) from all specimens of the R. australis complex while R. rufogrisea Magzoub, 1964 was closely related to one of the two species occuring in M. rufogriseus. It was concluded that R. australis is a species complex, with a genetically distinct species present in M. eugenii, M. fuliginosus/M. giganteus, M. robustus/M. rufus, W. bicolor and T. billardierii, and two species in M. rufogriseus.     

Detection by allozyme electrophoresis of cryptic species of Hypodontus macropi (Nematoda: Strongyloidea) from macropodid marsupials.

Allozyme electrophoresis of 98 Hypodontus macropi from eight different species of hosts using 24 enzymes revealed a complex of at least six sibling species, with 15-50% fixed genetic differences between taxa. Except for the taxon parasitizing Macropus rufus/M. robustus, pairs of parasite taxa were, in each case, sympatric at each locality examined, thus supporting the conclusion that they represent valid species. The existence of a series of host-specific nematode taxa explains many of the inconsistencies noted previously in the host distribution of H. macropi. Comparison of parasite allozyme phenograms with host phylogeny suggests that four of the speciation events could be attributable to cospeciation and two to host switching. A clear case of host switching between M. rufus/M. robustus and M. fuliginosus was found.     

Eimeria (Protozoa: Eimeriidae) of the Cottontail Rabbit Sylvilagus audubonii in Northeastern Colorado, with Descriptions of Three New Species

SYNOPSIS. All of 100 cottontail rabbits Sylvilagus audubonii were found to be infected with 1-6 species of Eimeria. Three new species, E. audubonii, E. neoirresidua and E. poudrei are described from this host. Sub-spherical oocysts of E. audubonii average 21.2 by 17.1 μ; polar body, micropyle, oocyst residuum and sporocyst residuum are all absent; ellipsoidal sporocysts average 12.9 by 5.8 μ. Ovoid to ellipsoidal oocysts of E. neoirresidua average 25.7 by 17.9 μ; polar body and oocyst residuum are absent; micropyle and sporocyst residuum are present; ellipsoidal sporocysts average 14.5 by 6.4 μ. Ovoid to ellipsoidal oocysts of E. poudrei average 26.0 by 18.1 μ; polar body is lacking; micropyle, oocyst residuum and sporocyst residuum are present; ellipsoidal sporocysts average 14.4 by 6.4 μ. Three species of Eimeria previously described in the literature, E. maior Honess, 1939, E. media form honessi Carvalho, 1943 and E. environ Honess, 1939 are redescribed. A detailed structural and statistical analysis of each species is presented with at least 200 sporulated oocysts measured in each instance. A host list and a key to the Eimeria of cottontails is given. The use of detailed studies of oocyst size and structure as a tool for specific diagnosis of the Eimeria of cottontails is discussed.     

Cryptosporidium fayeri n. sp. (Apicomplexa: Cryptosporidiidae) from the Red Kangaroo (Macropus rufus)

The morphology and infectivity of the oocysts of a new species of Cryptosporidium from the faeces of the red kangaroo (Macropus rufus) are described. Oocysts are structurally indistinguishable from those of Cryptosporidium parvum. Oocysts of the new species are passed fully sporulated, lack sporocysts, and measure 4.5-5.1 microm (mean=4.9) x 3.8-5.0 microm (mean=4.3 microm) with a length to width ratio 1.02:1.18 (mean 1.14) (n=50). Oocysts were not infectious for neonate ARC Swiss mice. Multi-locus analysis of numerous unlinked loci demonstrated this species to be distinct (90.64%-97.88% similarity) from C. parvum. Based on biological and molecular data, this Cryptosporidium infecting marsupials is proposed to be a new species Cryptosporidium fayeri n. sp.