Macropus Research Articles

Epigenetic clock and methylation studies in marsupials: opossums, Tasmanian devils, kangaroos, and wallabies

The opossum (Monodelphis domestica), with its sequenced genome, ease of laboratory care and experimental manipulation, and unique biology, is the most used laboratory marsupial. Using the mammalian methylation array, we generated DNA methylation data from n = 100 opossum samples from the ear, liver, and tail. We contrasted postnatal development and later aging effects in the opossum methylome with those in mouse (Mus musculus, C57BL/6 J strain) and other marsupial species such as Tasmanian devil, kangaroos, and wallabies. While the opossum methylome is similar to that of mouse during postnatal development, it is distinct from that shared by other mammals when it comes to the age-related gain of methylation at target sites of polycomb repressive complex 2. Our immunohistochemical staining results provide additional support for the hypothesis that PRC2 activity increases with later aging in mouse tissues but remains constant in opossum tissues. We present several epigenetic clocks for opossums that are distinguished by their compatibility with tissue type (pan-tissue and blood clock) and species (opossum and human). Two dual-species human-opossum pan-tissue clocks accurately measure chronological age and relative age, respectively. The human-opossum epigenetic clocks are expected to provide a significant boost to the attractiveness of opossum as a biological model. Additional epigenetic clocks for Tasmanian devil, red kangaroos and other species of the genus Macropus may aid species conservation efforts.

Molecular identification of Eimeria hestermani and Eimeria prionotemni from a red-necked wallaby (Macropodidae; Macropus rufogriseus) in Japan.

To date, more than 50 Eimeria spp. have been isolated from marsupials of the family Macropodidae. Although 18 species of Eimeria have been previously detected from multiple animal species belonging to the genus Macropus of the family, limited genetic analyses of the parasites are available, and their pathogenicity remains unclear. Here, we report the isolation of Eimeria spp. from a zoo specimen of red-necked wallaby (Macropodidae; Macropus rufogriseus). Specifically, two distinct types of Eimeria oocysts were recovered, one from the feces before treatment with an anthelmintic and the second from the intestinal contents after death of the animal. The oocysts obtained from the two sources were morphologically identified as E. hestermani and E. prionotemni, respectively. We successfully determined partial gene sequences from the two isolates, including segments of the 18S rRNA genes, and for the first time have used phylogenetic analyses of these sequences to assign the species to distinct clades. In combination with further genetic data, these results are expected to help elucidate the pathogenicity and host ranges of Eimeria spp. within the respective family and genus.

A molecular and morphometric assessment of the systematics of the Macropus complex clarifies the tempo and mode of kangaroo evolution

Kangaroos and wallabies of the Macropus complex include the largest extant marsupials and hopping mammals. They have traditionally been divided among the genus Macropus (with three subgenera: Macropus, Osphranter and Notamacropus) and the monotypic swamp wallaby, Wallabia bicolor. Recent retrotransposon and genome-scale phylogenetic analyses clarify the placement of Wallabia as sister to Notamacropus, with Osphranter and Macropus branching successively deeper. In view of the traditional Macropus concept being paraphyletic, we undertake to resolve the species-level phylogeny and genus-level taxonomy of the Macropus complex. For the first time, we include nuclear and mitochondrial DNA covering all extant species, and the first DNA sequences from the extinct Toolache wallaby (Notamacropus greyi), which we find groups with the black-gloved wallaby (Notamacropus irma). Morphological variation was examined using geometric morphometric methods on three-dimensional surface-scanned skulls. Wallabia skull shape fell close to Notamacropus (or Thylogale when controlling for allometry). We recommend the subgenera Macropus, Osphranter and Notamacropus be elevated to genera, alongside Wallabia, based on comparisons with other established macropodine genera for cranial disparity, ecology and molecular divergence. Our time tree estimates that all four ‘Macropus’ genera diverged close to the Miocene–Pliocene boundary (~6–5 Mya), then diversified coincident with Pliocene expansion of grasslands in Australia.

Behaviour and enclosure use of captive parma wallabies (Macropus parma): an assessment of compatibility within a mixed-species exhibit.

The parma wallaby (Macropus parma) is considered to be a species of conservation concern. Collaborative breeding programs for this cryptic animal are in place in many zoos worldwide. Many zoos choose to house parma wallabies in mixed-species exhibits and a successful combination of species can greatly improve breeding prospects. However, there are potential health and welfare concerns and species compatibility requires consideration. This study investigates if a previously unreported housing of the parma wallaby and the Patagonian mara (Doliochotis patagonum), is congruous. Parma wallabies at Dudley Zoological Gardens were observed in two different housing systems; mixed-species (MS) and single species (SS) for nine days. Scan sampling of all individuals, across a range of behaviours previously reported for this species, was carried out at three 30 minute periods across the day. Differences in foraging behaviour were noted with parmas housed in the MS foraging significantly less than the SS group (p<0.01). A novel behaviour, agonistic directional urination, was also observed in the MS enclosure which was not observed within the SS group. Utilisation of the enclosure was analysed using a Spread of Participation Index (SPI); values revealed MS parmas utilised less of their enclosure, with a notable preference for areas not frequented by mara (W27=899.0, p<0.05). The MS parmas appeared to be affected by the presence of the mara, both behaviourally and in their enclosure use, this could be indicative of a negative welfare state. This study provides an indicator of species incompatibility, potentially affecting the welfare of captive parma wallabies and the future conservation of the species, and requires further investigation.

Reassembling haplotypes in a mixture of pooled amplicons when the relative concentrations are known: A proof-of-concept study on the efficient design of next-generation sequencing strategies

Next-generation sequencing can be costly and labour intensive. Usually, the sequencing cost per sample is reduced by pooling amplified DNA = amplicons) derived from different individuals on the same sequencing lane. Barcodes unique to each amplicon permit short-read sequences to be assigned appropriately. However, the cost of the library preparation increases with the number of barcodes used. We propose an alternative to barcoding: by using different known proportions of individually-derived amplicons in a pooled sample, each is characterised a priori by an expected depth of coverage. We have developed a Hidden Markov Model that uses these expected proportions to reconstruct the input sequences. We apply this method to pools of mitochondrial DNA amplicons extracted from kangaroo meat, genus Macropus. Our experiments indicate that the sequence coverage can be efficiently used to index the short-reads and that we can reassemble the input haplotypes when secondary factors impacting the coverage are controlled. We therefore demonstrate that, by combining our approach with standard barcoding, the cost of the library preparation is reduced to a third.

Speciation Generates Mosaic Genomes in Kangaroos.

The iconic Australasian kangaroos and wallabies represent a successful marsupial radiation. However, the evolutionary relationship within the two genera, Macropus and Wallabia, is controversial: mitochondrial and nuclear genes, and morphological data have produced conflicting scenarios regarding the phylogenetic relationships, which in turn impact the classification and taxonomy. We sequenced and analyzed the genomes of 11 kangaroos to investigate the evolutionary cause of the observed phylogenetic conflict. A multilocus coalescent analysis using ∼14,900 genome fragments, each 10 kb long, significantly resolved the species relationships between and among the sister-genera Macropus and Wallabia. The phylogenomic approach reconstructed the swamp wallaby (Wallabia) as nested inside Macropus, making this genus paraphyletic. However, the phylogenomic analyses indicate multiple conflicting phylogenetic signals in the swamp wallaby genome. This is interpreted as at least one introgression event between the ancestor of the genus Wallabia and a now extinct ghost lineage outside the genus Macropus. Additional phylogenetic signals must therefore be caused by incomplete lineage sorting and/or introgression, but available statistical methods cannot convincingly disentangle the two processes. In addition, the relationships inside the Macropus subgenus M. (Notamacropus) represent a hard polytomy. Thus, the relationships between tammar, red-necked, agile, and parma wallabies remain unresolvable even with whole-genome data. Even if most methods resolve bifurcating trees from genomic data, hard polytomies, incomplete lineage sorting, and introgression complicate the interpretation of the phylogeny and thus taxonomy.

Empirical tests of harvest-induced body-size evolution along a geographic gradient in Australian macropods.

Life-history theory predicts the progressive dwarfing of animal populations that are subjected to chronic mortality stress, but the evolutionary impact of harvesting terrestrial herbivores has seldom been tested. In Australia, marsupials of the genus Macropus (kangaroos and wallabies) are subjected to size-selective commercial harvesting. Mathematical modelling suggests that harvest quotas (c. 10-20% of population estimates annually) could be driving body-size evolution in these species. We tested this hypothesis for three harvested macropod species with continental-scale distributions. To do so, we measured more than 2000 macropod skulls sourced from wildlife collections spanning the last 130years. We analysed these data using spatial Bayesian models that controlled for the age and sex of specimens as well as environmental drivers and island effects. We found no evidence for the hypothesized decline in body size for any species; rather, models that fit trend terms supported minor body size increases over time. This apparently counterintuitive result is consistent with reduced mortality due to a depauperate predator guild and increased primary productivity of grassland vegetation following European settlement in Australia. Spatial patterns in macropod body size supported the heat dissipation limit and productivity hypotheses proposed to explain geographic body-size variation (i.e. skull size increased with decreasing summer maximum temperature and increasing rainfall, respectively). There is no empirical evidence that size-selective harvesting has driven the evolution of smaller body size in Australian macropods. Bayesian models are appropriate for investigating the long-term impact of human harvesting because they can impute missing data, fit nonlinear growth models and account for non-random spatial sampling inherent in wildlife collections.

Inferring Kangaroo Phylogeny from Incongruent Nuclear and Mitochondrial Genes

The marsupial genus Macropus includes three subgenera, the familiar large grazing kangaroos and wallaroos of M. (Macropus) and M. (Osphranter), as well as the smaller mixed grazing/browsing wallabies of M. (Notamacropus). A recent study of five concatenated nuclear genes recommended subsuming the predominantly browsing Wallabia bicolor (swamp wallaby) into Macropus. To further examine this proposal we sequenced partial mitochondrial genomes for kangaroos and wallabies. These sequences strongly favour the morphological placement of W. bicolor as sister to Macropus, although place M. irma (black-gloved wallaby) within M. (Osphranter) rather than as expected, with M. (Notamacropus). Species tree estimation from separately analysed mitochondrial and nuclear genes favours retaining Macropus and Wallabia as separate genera. A simulation study finds that incomplete lineage sorting among nuclear genes is a plausible explanation for incongruence with the mitochondrial placement of W. bicolor, while mitochondrial introgression from a wallaroo into M. irma is the deepest such event identified in marsupials. Similar such coalescent simulations for interpreting gene tree conflicts will increase in both relevance and statistical power as species-level phylogenetics enters the genomic age. Ecological considerations in turn, hint at a role for selection in accelerating the fixation of introgressed or incompletely sorted loci. More generally the inclusion of the mitochondrial sequences substantially enhanced phylogenetic resolution. However, we caution that the evolutionary dynamics that enhance mitochondria as speciation indicators in the presence of incomplete lineage sorting may also render them especially susceptible to introgression.

Phylogenetic relationships of species within the tribe Labiostrongylinea (Nematoda: Cloacinidae) from Australian marsupials based on ribosomal DNA spacer sequence data

Parasitic nematodes of the tribe Labiostrongylinea (Family Cloacinidae) occur in the stomachs of a wide variety of potoroid and macropodid marsupials in Australia, Papua Indonesia and Papua New Guinea. The aim of the present study was to infer the evolutionary relationships of the five genera of labiostrongyline nematodes that occur in Australian potoroids and macropodids using sequence data of the nuclear first and second internal transcribed spacers of ribosomal DNA. The phylogenetic analyses resulted in the separation of the Labiostrongylinea into two major groups reflecting coevolution between hosts and parasites. Two nematode species belonging to the genus Potorostrongylus formed a sister group to the remaining species of the Labiostrongylinea. This genus occurs exclusively in potoroid marsupials, which are considered to be basal to the macropodid marsupials. The second major group included species of Labiostrongylus, Labiosimplex, Labiomultiplex and Parazoniolaimus, all of which occur in macropodids. These species formed two distinct clades, one predominating in the host genera Thylogale and Onychogalea, and the second in the genus Macropus, which includes the more recent macropodids. However, there is also evidence of colonisation by both nematode clades of relatively unrelated hosts. In addition, genetic differences among individuals of Lm. eugenii from geographically isolated populations of M. eugenii, and among Ls. longispicularis from different subspecies of M. robustus suggest the existence of sibling species that may have arisen by allopatric speciation. The broad coevolutionary relationship between the labiostrongyline nematodes and their marsupial hosts therefore represents a mixture of potential cospeciation and colonisation events.

Species-specific shifts in centromere sequence composition are coincident with breakpoint reuse in karyotypically divergent lineages

The evolution of three classes of centromere sequences across nine species of macropodine marsupials were compared with that of other genes, showing that each species has experienced differential expansion and contraction of individual classes.

GROUP SIZE BUT NOT DISTANCE TO COVER INFLUENCES AGILE WALLABY (MACROPUS AGILIS) TIME ALLOCATION

Despite their widespread distribution and relative abundance, little is known about the antipredator behavior of agile wallabies (Macropus agilis). The ability to modify time allocation as a function of group size is an antipredator behavior that has been reported in some, but not all, previous studies of members of the genus Macropus. We studied group-size effects and space use for agile wallabies foraging in the open to develop a better understanding of behavior of mid-sized macropods. We found that agile wallabies modified time allocated to foraging and vigilance as a function of group size but were insensitive to distance from cover. We contrast the group size results from agile wallabies with those from other macropodids and speculate that predation by saltwater crocodiles (Crocodylus porosus) may have a profound effect on how agile wallabies perceive and manage predation risk.

Elaeocarpus for Flora Malesiana: The Coilopetalum Group in Sulawesi &amp; Maluku

The ten species of Elaeocarpus of the Coilopetalum group from Sulawesi (Celebes) and Maluku (the Moluccas) are discussed and sixteen taxa keyed out and accounted for. Six new species are described: E. balgooyi Coode, E. batui Coode, E. takolensis Coode, E. erdinii Coode and E. harunii Coode, all from Sulawesi, and E. seramicus Coode from Maluku. E. lancipetalus Merr. is resuscitated (from the synonymy of E. branderhorstii Pulle) and two new subspecies, subsp. mediocris Coode from Maluku and subsp. tuberculatus Coode from Obi I., are described; E. macropus Warb. is recognised and a new subspecies thenui Coode is described; E. octopetalus Merr. is recognised and two new subspecies subsp. darnaedii Coode and subsp. teruyae Coode from Sulawesi are described; E. rumphii Merr. is recognised and one new subspecies ternatensis Coode described. E. multiflorus (Turcz.) Fern.-Vill. is recognised and E. moluccanus Scheff. & E. minahassensis R. Knuth are sunk into it. E. crenatus (Raf.) Merr., based on Rumphius' Arbor rediviva, is listed as inadequately known.

Sex Determination of The Whiptail Wallaby, Macropus parryi, Using Adult Skulls.

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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 Aepyprymnas 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 the 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 that 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 the topology at each step should be conducted.

Host-parasite associations of Eimeria spp. (Apicomplexa:Eimeriidae) in kangaroos and wallabies of the genus Macropus (Marsupialia:Macropodidae)

Faecal samples from 514 kangaroos and wallabies representing 12 species of the genus Macropus were examined for oocysts of Eimeria spp. Six species of Eimeria were redescribed from their type hosts, and on the basis of finding homologous oocysts in the faeces of other Macropus spp., host ranges for these coccidia were extended. Eimeria hestermani Mykytowycz, 1964 is redescribed from M. giganteus (eastern grey kangaroo) and is described from M. fuliginosus (western grey kangaroo), M. rufogriseus (red-necked wallaby), M. dorsalis (black-striped wallaby), and M. eugenii (tammar wallaby). E. toganmainensis Mykytowycz, 1964 is redescribed from M. rufus (red kangaroo) and the host range is extended to M. giganteus, M. fuliginosus, M. rufogriseus and M. eugenii. E. wilcanniensis Mykytowycz, 1964 is redescribed from M. rufus, and the host range is extended to M. giganteus, M. fuliginosus and M. robustus (euro or wallaroo). E. macropodis Wenyon & Scott, 1925 is redescribed from M. rufogriseus, and is described from M. giganteus, M. fuliginosus, M. rufus, M. irma (western brush wallaby), M. parryi (whip-tailed wallaby), M. dorsalis, M. eugenii, and M. parma (parma wallaby). E. fausti Yakimoff & Matschoulsky, 1936, E. cunnamullensis Mykytowycz, 1964 and E. purchasei Mykytowycz, 1964 are synonymized with E. macropodis. E. marsupialium Yakimoff & Matschoulsky, 1936 is redescribed from M. giganteus, and from M. fuliginosus. E. gungahlinensis Mykytowycz, 1964 is redescribed from M. fuliginosus, and from M. giganteus. Seven new species of Eimeria are described. E. flindersi, new species, is described from M. eugenii, M. rufogriseus, and M. antilopinus (antilopine wallaroo). E. prionotemni, new species, is described from M. eugenii, M. parryi, M. rufogriseus, M. agilis (agile wallaby) and M. dorsalis. E. mykytowyczi, new species, is described from M. agilis, M. antilopinus, and M. parryi. E. parryi, new species, is described from M. parryi. E. yathongensis, new species, is described from M. fuliginosus and M. giganteus. E. parma, new species, is described from M. parma, and E. desmaresti, new species, is described from M. rufogriseus. E. kogoni Mykytowycz, 1964, and E. rufusi Prasad, 1960 are considered species inquirendae. The hostparasite associations of these coccidia, and of similar species of Eimeria in other genera of Macropodoid marsupials, are discussed in relation to the postulated phylogeny of the hosts.

Evolutionary Relationships of Australian Marsupials as Assessed by Albumin Immunology

Current phylogenetic hypotheses of the relationships of Australian marsupials were tested by microcomplement fixation of albumin. The study involved antisera to albumins of 56 species, and cross- reactions to albumins of 199 species. The most notable and controversial features of the study were as follows. (1) Two major lineages are evident among the Australian marsupials- bandicoots-dasyuroids and diprotodontids; the marsupial mole represents a third lineage. (2) The honey possum Tarsipes is clearly a diprotodontid. (3) Acrobates and Distoechurus are monophyletic, but they are not burramyids; they are closely related to Tarsipes; moreover the Acrobates-Distoechurus-Tarsipes clade may be close to petaurids. (4) The New Guinean species of Antechinus are more closely related to the New Guinean Murexia than to Australian species of Antechinus. (5) The bandicoots fall into two groups-the New Guinean genera and the Australian genera; the bilby, Macrotis lagotis, is not clearly distinct from the bandicoots, and may be monophyletic with the New Guinean genera. (6) The banded hare-wallaby Lagostrophus is clearly the sister-group to all other extant macropodines, and may be monophyletic with potoroines rather than macropodines. (7) The genus Macropus may be paraphyletic. (8) The tree-kangaroos Dendrolagus may be closely related to the rock-wallabies and their allies (Petrogale, Peradorcas and Thylogale). (9) The genus Pseudocheirus (ringtail possums) is paraphyletic and its species are highly divergent at the molecular level. (10) The cuscuses (genus Phalanger) are probably a monophyletic assemblage.

Taxonomic and Phylogenetic Status of Living and Fossil Kangaroos and Wallabies of the Genus Macropus Shaw (Macropodidae: Marsupialia), with a New Subgeneric Name for the Larger Wallabies

Historical concepts of the generic status of the macropodines commonly known as kangaroos and wallabies are reviewed in this paper. A new diagnosis is provided for the genus Macropus, encompassing both living and fossil forms, and using cladistic principles to assess the phylogenetic value of diagnostic characters where possible. Cytological, biochemical and anatomical characters are used. Fourteen living and 11 extinct species of Macropus are recognized. Of these, 20 species have been classified into three subgenera, M.(Macropus), M.(Osphranter) and a new subgenus, M.(Notamacropus), as follows: M.(M.) giganteus, M.(M.) fuliginosus, M.(M.) mundjabus, M.(M.) pan, M.(M.) pearsoni and M.(M.) ferragus; M.(O.) antilopinus, M.(O.) bernardus, M.(O.) robustus, M.(O.) rufus and M.(O.) pavana; ,M.(N.) rufogriseus, M.(N.) eugenii, M.(N.) parryi, M.(N.) dorsalis, M.(N.) irma, M.(N.) agilis, M.(N.) greyi, M.(N.) parma, M.(N.) wombeyensis and M.(N) thor. Four poorly known extinct species, M. dryas, M. rama, M. woodsi and M. narada, have not yet been allocated to a subgenus. Prionotemnus palankarinnicus Stirton, 1957 is shown to belong outside Macropus. Because it is the type-species of Prionotemnus, that name is not available for a subgenus of Macropus. A current synonymy is presented for fossil species and the known stratigraphic range is given for each species. A phylogeny is presented expressing our view that M. (,Votamacropus) is the most plesiomorphic subgenus and M. (Macropus) is the most derived.

Further Studies of Lung Parasites (Nematoda) From Australian Marsupials.

Seven new taxa in two families of metastrongyloid nematodes are described from the lungs of five host species belonging to the Dasyuridae, Phalangeridae and Macropodidae. Filaroides (Filaroides) athertonensis, sp. nov., (Filaroididae) is described from Thylogale stigmatica Gould in north Queensland. The following species of Marsupostrongylus Mackerras &amp; Sandars, 1953, (Angiostrongylidae) are described as new: M. parallelus, sp. nov., from Satanellus hallucatus (Could) in the Northern Territory; M. pseudominesi, sp. nov., from Trichosurus vulpecula johnstonii (Ramsay) in north Queensland; M. vandiemeni, sp. nov., from macro pus rufogriseus rufogriseus (Desmarest) in Tasmania; and M. wallabiae, sp. nov., from Wallabia bicolor (Desmarest) and Macropus rufogriseus banksianus (Quoy &amp; Gaimard) in New South Wales. To the formerly monotypic genus Filostrongylus Mackenas, 1955, (Angiostrongylidae) is added F. tridendriticus, sp. nov., described from Trichosurus vulpecula (Kerr) in Tasmania. The genus Cosmostrongylus (Angiostrongylidae) is described as new, with a single species C. conspectus, sp. nov., from Thylogale stigmatica Gould in north Queensland. Durikainema sp. (Muspiceoidea: Robertdollfusidae) is diagnosed in histological sections of the lungs of Phascolarctos cinereus (Goldfuss), Macropus agilis (Could) and M. giganteus Shaw. Keys to the genera of lung parasites and to all species of Filaroides, Marsupostrongylus and Filostrongylus known from Australian marsupials, new host and new geographic records of known taxa, and a host-parasite list of lung parasites of Australian marsupials, including those known only from histological sections of lung tissue, are provided.

The Macropodid Oesophagus I. Gross Anatomical, Light Microscopic, Scanning and Transmission Electron Microscopic Observations of its Mucosa

The results of examinations on the oesophagus of 248 animals of 36 species of macropodid marsupials are presented in this paper. Four distinct morphological types of oesophageal lining are described and the species examined classified accordingly. The oesophagus of Aepyprymnus: Bettongia, Dendrolagus, Hypsiprymnodon, Onychogalea; Petrogale; Peradorcas, Setonix and Thylogale has a smooth lining with small and simple longitudinal folds (type 1). The large kangaroos of the genus Macropus (M. antilopinus. M. bernardus, M. fuliginosus, M. giganteus. M. robustus, and M. rufus) have smooth oesophageal linings with extensively pleated longitudinal folds (type 11). The so-called brush wallabies of the genus Macropus (M. agilis, M. dorsalis, M. eugenii, M. irma; M. parma and M. parryi) and Wallabia bicolor have papillated oesophageal linings (type 111). In the red-necked wallaby M. rufogriseus banksianus and the Bennett's wallaby M. r. rufogriseus the oesophagus proximal to the diaphragm is lined with longitudinal leaf-like, laminar plates. and distal to the diaphragm the lining consists of finger-like papillae (type IV). The morphology of the oesophagus in the various macropodid species is discussed in relation to dietary preferences, habitat. and phylogenetic associations between species.

Marsupial neurohypophysial hormones: Identification of mesotocin, lysine vasopressin, and phenypressin in the quokka wallaby ( Setonix brachyurus)

The neurohypophysial hormones of the quokka wallaby ( Setonix brachyurus) have been isolated through preparative high pressure liquid chromatography (HPLC). One oxytocin-like and two vasopressin-like peptides have been found. These peptides have been characterized by their amino acid composition and by their retention time in HPLC. Mesotocin ([Ile 8]-oxytocin) has been identified by amino acid composition, polar partition chromatography, high pressure liquid chromatography with a reversed phase column, and pharmacological properties. Lysine vasopressin and phenypressin ([Phe 2]-arginine vasopressin) have been characterized by amino acid composition, ion-exchange chromatography, and high pressure liquid chromatography. Lysine vasopressin is about twice as abundant as phenypressin. These three peptides have previously been found in three species belonging to the genus Macropus, namely the red kangaroo, the Eastern gray kangaroo, and the tammar wallaby; they are therefore current in the family Macropodidae. Comparison with other native Australian mammals is discussed.