Redescriptions of two species of microcotylid monogeneans from three arripid hosts in southern Australian waters

Microcotyle arripis Sandars, 1945 is redescribed from Arripis georgianus from four localities: Spencer Gulf, Gulf St. Vincent, off Kangaroo Island and Coffin Bay, South Australia, Australia. Kahawaia truttae (Dillon & Hargis, 1965) Lebedev, 1969 is reported from A. trutta off Bermagui, New South Wales and is redescribed from a new host, A. truttaceus, from four localities in South Australian waters: Spencer Gulf, Gulf St. Vincent, off Kangaroo Island and Coffin Bay. Phylogenetic analysis of the partial 28S ribosomal RNA gene (28S rRNA) nucleotide sequences for both microcotylid species and comparison with other available sequence data for microcotylid species across four genera contributes to our understanding of relationships in this monogenean family.     

Prenylated cinnamate and stilbenes from Kangaroo Island propolis and their antioxidant activity

A prenylated cinnamic acid derivative as well as six prenylated tetrahydroxystilbenes were isolated from the ethyl acetate extract of propolis that originated from Kangaroo Island, Australia. Furthermore, six known stilbenes and two known flavanones were also identified from the same sample. Stilbenes are not common in propolis; therefore, Kangaroo Island propolis is considered a unique type of propolis that is rich in prenylated stilbenes. Stilbene propolis from Kangaroo Island showed a stronger scavenging activity towards DPPH free radical than Brazilian green propolis. This strong activity can be explained by the presence of large number of stilbenes, most of them showed strong free radical scavenging activity.     

PVC nest boxes are less at risk of occupancy by feral honey bees than timber nest boxes and natural hollows

Feral European Honey Bee (Apis mellifera) has been identified as a potential nest competitor for Australian hollow nesting species, but few studies have investigated the impact of feral honey bee competition on Threatened species. Our study used data from Glossy Black‐cockatoo (Calyptorhynchus lathami halmaturinus) nests on Kangaroo Island, monitored and managed over an 11‐year period, and found 12% of nests became occupied by feral honey bees during that period. Our results indicate that feral honey bees were less likely to occupy nest boxes made of PVC (5%) compared with wooden nest boxes (24%) or natural hollows in Eucalyptus trees (14%). The removal of feral honey bee hives from nests is a priority for long‐term conservation of glossy black‐cockatoos on Kangaroo Island. We recommend that PVC nest boxes are chosen for future nesting habitat restoration, due to the more frequent use of wooden nest boxes by feral honey bees.     

Monostephanostomum georgianum n. sp. (Digenea: Acanthocolpidae) from Arripis georgianus (Valenciennes) (Perciformes: Arripidae) off Kangaroo Island,South Australia,with comments on Monostephanostomum Kruse, 1979 and Stephanostomum Looss, 1899

Monostephanostomum georgianum n. sp. is described from Arripis georgianus off Kangaroo Island, South Australia. It differs from its congeners by the presence of a short second row of oral spines. M. manteri Kruse, 1979 is reported from A. georgianus off southern Western Australia and Kangaroo Island, South Australia and A. trutta off northern Tasmania. It is considered that the other two species, M. yamagutii Ramadan, 1984 and M. krusei Reimer, 1983, should probably be removed from this genus. Two new combinations are formed, M. gazzae (Shen, 1990) n. comb. (from Stephanostomum) and M. mesospinosum (Madhavi, 1976) n. comb. (from Stephanostomum). A key to the four recognised species of Monostephanostomum is given.     

Small population size and extremely low levels of genetic diversity in island populations of the platypus, Ornithorhynchus anatinus

Genetic diversity generally underpins population resilience and persistence. Reductions in population size and absence of gene flow can lead to reductions in genetic diversity, reproductive fitness, and a limited ability to adapt to environmental change increasing the risk of extinction. Island populations are typically small and isolated, and as a result, inbreeding and reduced genetic diversity elevate their extinction risk. Two island populations of the platypus, Ornithorhynchus anatinus, exist; a naturally occurring population on King Island in Bass Strait and a recently introduced population on Kangaroo Island off the coast of South Australia. Here we assessed the genetic diversity within these two island populations and contrasted these patterns with genetic diversity estimates in areas from which the populations are likely to have been founded. On Kangaroo Island, we also modeled live capture data to determine estimates of population size. Levels of genetic diversity in King Island platypuses are perilously low, with eight of 13 microsatellite loci fixed, likely reflecting their small population size and prolonged isolation. Estimates of heterozygosity detected by microsatellites (H(E)= 0.032) are among the lowest level of genetic diversity recorded by this method in a naturally outbreeding vertebrate population. In contrast, estimates of genetic diversity on Kangaroo Island are somewhat higher. However, estimates of small population size and the limited founders combined with genetic isolation are likely to lead to further losses of genetic diversity through time for the Kangaroo Island platypus population. Implications for the future of these and similarly isolated or genetically depauperate populations are discussed.     

Fire‐related cues and germination from the soil seed bank of senescent remnants of mallee vegetation on Eastern Kangaroo Island

Plant communities dominated by narrow‐leaved mallee (Eucalyptus cneorifolia) are almost entirely confined to north‐eastern Kangaroo Island, South Australia, an area which has been extensively cleared for agriculture. Consequently, surviving examples consist mostly of small remnants which are thought to be senescent due to the exclusion of fire. This senescence is associated with the loss of many native understory species. Prescribed burns have been suggested as a management tool to stimulate the restoration of native plants from the soil seed bank; however, no seed bank studies have previously been conducted on Kangaroo Island and the seed bank literature usually focuses on particular species rather than on plant communities. We conducted an experiment to investigate the effects of the fire‐related cues heat and smoke on the germination of plants from the seed bank in soil sampled from 10 long‐ungrazed narrow‐leaved mallee sites on Kangaroo Island. Eighty trays of soil were monitored in a controlled glasshouse for five months after being subjected to heat and/or smoke treatments. The overall number of native, but not exotic, plant species germinating from the soil seed bank was significantly increased by all three fire‐related treatments (heat, smoke and heat plus smoke) compared with the control (no fire‐related treatment). Different plant life forms exhibited varying responses to heat and smoke treatments. The results of this study illustrate that the application of fire‐related treatments to soil seed banks in controlled glasshouse conditions can stimulate the recruitment of native species, including several species of conservation concern. These findings also indicate the potential of using these treatments for the ex situ germination of fire dependent species for revegetation purposes and indicate aspects of prescribed burns that may be important for restoring different components of native vegetation.     

Eggs of extinct dwarf island emus retained large size

Islands off southern Australia once harboured three subspecies of the mainland emu (Dromaius novaehollandiae), the smaller Tasmanian emu (D. n. diemenensis) and two dwarf emus, King Island emu (D. n. minor) and Kangaroo Island emu (D. n. baudinianus), which all became extinct rapidly after discovery by European settlers. Little was recorded about their life histories and only a few historical museum specimens exist, including a number of complete eggs from Tasmania and a unique egg from Kangaroo Island. Here, we present a detailed analysis of eggs of dwarf emus, including the first record of an almost complete specimen from King Island. Our results show that despite the reduction in size of all island emus, especially the King Island emu that averaged 44% smaller than mainland birds, the egg remained similar sized in linear measurements, but less in volume and mass, and seemingly had a slightly thinner eggshell. We provide possible reasons why these phenomena occurred.     

Phylogeographic structure,demographic history and morph composition in a colour polymorphic lizard

In polymorphic species, population divergence in morph composition and frequency has the potential to promote speciation. We assessed the relationship between geographic variation in male throat colour polymorphism and phylogeographic structure in the tawny dragon lizard, Ctenophorus decresii. We identified four genetically distinct lineages, corresponding to two polymorphic lineages in the Northern Flinders Ranges and Southern Flinders Ranges/Olary Ranges regions respectively, and a monomorphic lineage in the Mt Lofty Ranges/Kangaroo Island region. The degree of divergence between these three lineages was consistent with isolation to multiple refugia during Pleistocene glacial cycles, whereas a fourth, deeply divergent (at the interspecific level) and monomorphic lineage was restricted to western New South Wales. The same four morphs occurred in both polymorphic lineages, although populations exhibited considerable variation in the frequency of morphs. By contrast, male throat coloration in the monomorphic lineages differed from each other and from the polymorphic lineages. Our results suggest that colour polymorphism has evolved once in the C. decresii species complex, with subsequent loss of polymorphism in the Mt Lofty Ranges/Kangaroo Island lineage. However, an equally parsimonious scenario, that polymorphism arose independently twice within C. decresii, could not be ruled out. We also detected evidence of a narrow contact zone with limited genotypic admixture between the polymorphic Olary Ranges and monomorphic Mt Lofty Ranges regions, yet no individuals of intermediate colour phenotype. Such genetic divergence and evidence for barriers to gene flow between lineages suggest incipient speciation between populations that differ in morph composition.     

Diversity at the major histocompatibility complex Class II in the platypus, Ornithorhynchus anatinus

The platypus (Ornithorhynchus anatinus) is the sole survivor of a previously widely distributed and diverse lineage of ornithorhynchid monotremes. Its dependence on healthy water systems imposes an inherent sensitivity to habitat degradation and climate change. Here, we compare genetic diversity at the major histocompatibility complex (MHC) Class II-DZB gene and 3 MHC-associated microsatellite markers with diversity at 6 neutral microsatellite markers in 70 platypuses from across their range, including the mainland of Australia and the isolated populations of Tasmania, King Island, and Kangaroo Island. Overall, high DZB diversity was observed in the platypus, with 57 DZB β1 alleles characterized. Significant positive selection was detected within the DZB peptide-binding region, promoting variation in this domain. Low levels of genetic diversity were detected at all markers in the 2 island populations, King Island (endemic) and Kangaroo Island (introduced), with the King Island platypuses monomorphic at the DZB locus. Loss of MHC diversity on King Island is of concern, as the population may have compromised immunological fitness and reduced ability to resist changing environmental conditions.     

Polymorphic microsatellite markers for chromosomal races of Australian morabine grasshoppers (Vandiemenella,viatica species group)

Chromosomally diverse Australian morabine grasshoppers (genus Vandiemenella, viatica species group) have parapatric distributions and occasionally hybridize at contact zones. To investigate population genetic structure and the extent of gene flow between chromosomal races/species of Vandiemenella, we isolated and characterized nine polymorphic microsatellite loci and one insertion/deletion polymorphic locus. The numbers of alleles per locus ranged from two to 34 across three chromosomal races on Kangaroo Island, South Australia, and expected heterozygosity within races ranged from 0.00 to 0.94. Inter‐taxon amplification was generally successful within Vandiemenella, but not for other morabine genera.     

East–west genetic differentiation in Musk Ducks (<Emphasis Type="Italic">Biziura lobata</Emphasis>) of Australia suggests late Pleistocene divergence at the Nullarbor Plain

Musk Ducks (Biziura lobata) are endemic to Australia and occur as two geographically isolated populations separated by the Nullarbor Plain, a vast arid region in southern Australia. We studied genetic variation in Musk Duck populations at coarse (eastern versus western Australia) and fine scales (four sites within eastern Australia). We found significant genetic structure between eastern and western Australia in the mtDNA control region (Φ_ST = 0.747), one nuclear intron (Φ_ST = 0.193) and eight microsatellite loci (F_ST = 0.035). In contrast, there was little genetic structure between Kangaroo Island and adjacent mainland regions within eastern Australia. One small population of Musk Ducks in Victoria (Lake Wendouree) differed from both Kangaroo Island and the remainder of mainland eastern Australia, possibly due to genetic drift exacerbated by inbreeding and small population size. The observed low pairwise distance between the eastern and western mtDNA lineages (0.36%) suggests that they diverged near the end of the Pleistocene, a period characterised by frequent shifts between wet and arid conditions in central Australia. Our genetic results corroborate the display call divergence and Mathews’ (Austral Avian Record 2:83–107, 1914) subspecies classification, and confirm that eastern and western populations of Musk Duck are currently isolated from each other.     

The bivalved arthropods Isoxys and Tuzoia with soft‐part preservation from the Lower Cambrian Emu Bay Shale Lagerstätte (Kangaroo Island,Australia)

Abstract: Abundant material from a new quarry excavated in the lower Cambrian Emu Bay Shale (Kangaroo Island, South Australia) and, particularly, the preservation of soft‐bodied features previously unknown from this Burgess Shale‐type locality, permit the revision of two bivalved arthropod taxa described in the late 1970s, Isoxys communis and Tuzoia australis. The collections have also produced fossils belonging to two new species: Isoxys glaessneri and Tuzoia sp. Among the soft parts preserved in these taxa are stalked eyes, digestive structures and cephalic and trunk appendages, rivalling in quality and quantity those described from better‐known Lagerstätten, notably the lower Cambrian Chengjiang fauna of China and the middle Cambrian Burgess Shale of Canada.     

Propolis with high flavonoid content collected by honey bees from Acacia paradoxa

Honey bees, Apis mellifera var ligustica, on Kangaroo Island, Australia, were found to collect propolis from the sticky exudate on the stem shoots and seed pods of an Australian endemic plant, Acacia paradoxa. Extracts of the plant stem shoots and seed pods, the propolis carried on the legs of bees and freshly collected propolis in hives contained major flavonoid components consisting of 2′,3′,4′-trimethoxychalcone, 2′-hydroxy-3′,4′-dimethoxychalcone, 2′,4′-dihydroxy-3′-methoxychalcone, 5,7-dihydroxy-2,3-dihydroflavonol 3-acetate (pinobanksin 3-acetate) and 5,7-dihydroxy-6-methoxy-2,3-dihydroflavonol 3-acetate, a substance not previously characterized. HPLC and ¹H NMR analyses of the propolis and plant extracts indicated smaller amounts of other flavonoids. A survey of propolis samples from 47 apiary sites widely distributed on Kangaroo Island showed that 15 samples from 6 sites were largely sourced from A. paradoxa.     

The life history of Labiostrongylus eugenii, a nematode parasite of the Kangaroo Island Wallaby (Macropus eugenii): The parasitic stages

Smales L. R. 1977. The life history of Labiostrongylus eugenii, a nematode parasite of the Kangaroo Island Wallaby (Macropus eugenii): the parasitic stages. International Journal for Parasitology7: 457–461. Labiostrongylus eugenii infective larvae ingested by the Kangaroo Island Wallaby exsheathe on the saccular stomach wall, then invade the mucosa causing one or two chronic irritative hyperpastic nodules, each containing a number of larvae. Six to eight weeks later the larvae leave the stomach wall and moult to fourth-stage. The fourth-stage larva is characterized by eight lips, while the oesophagus and anterior intestine assume the adult form. The posterior ends of late fourth-stage larvae become sexually differentiated. Moulting to adult occurs after 6–8 weeks with the first gravid females being observed 3 months later. The prepatent period appears to last about 6 months. Reasons for failure of experimental infection trials and the epidemiological significance of the life cycle were discussed.     

High levels of genetic variation at MHC class II DBB loci in the tammar wallaby (<Emphasis Type="Italic">Macropus eugenii</Emphasis>)

High levels of MHC diversity are crucial for immunological fitness of populations, with island populations particularly susceptible to loss of genetic diversity. In this study, the level of MHC class II DBB diversity was examined in tammar wallabies (Macropus eugenii) from Kangaroo Island by genotyping class II-linked microsatellite loci and sequencing of DBB genes. Here we show that the tammar wallaby has at least four expressed MHC class II DBB loci and extensive genetic variation in the peptide-binding region of the DBB genes. These results contradict early studies which suggested that wallabies lacked MHC class II diversity and demonstrate that, in spite of the long-term isolation on an offshore island, this population of wallabies has a high level of DBB diversity.     

Sex-linked and autosomal microsatellites provide new insights into island populations of the tammar wallaby

The emerging availability of microsatellite markers from mammalian sex chromosomes provides opportunities to investigate both male- and female-mediated gene flow in wild populations, identifying patterns not apparent from the analysis of autosomal markers alone. Tammar wallabies (Macropus eugenii), once spread over the southern mainland, have been isolated on several islands off the Western Australian and South Australian coastlines for between 10 000 and 13 000 years. Here, we combine analyses of autosomal, Y-linked and X-linked microsatellite loci to investigate genetic variation in populations of this species on two islands (Kangaroo Island, South Australia and Garden Island, Western Australia). All measures of diversity were higher for the larger Kangaroo Island population, in which genetic variation was lowest at Y-linked markers and highest at autosomal markers (θ=3.291, 1.208 and 0.627 for autosomal, X-linked and Y-linked data, respectively). Greater relatedness among females than males provides evidence for male-biased dispersal in this population, while sex-linked markers identified genetic lineages not apparent from autosomal data alone. Overall genetic diversity in the Garden Island population was low, especially on the Y chromosome where most males shared a common haplotype, and we observed high levels of inbreeding and relatedness among individuals. Our findings highlight the utility of this approach for management actions, such as the selection of animals for translocation or captive breeding, and the ecological insights that may be gained by combining analyses of microsatellite markers on sex chromosomes with those derived from autosomes.     

New microsatellite markers for the bush rat,Rattus fuscipes greyii: characterization and cross‐species amplification

We describe here 16 new microsatellite markers for the bush rat, Rattus fuscipes greyii, and characterize their cross‐species amplification within the Australian Rattus and at a greater level of divergence in Rattus rattus and Rattus norvegicus. Within R. f. greyii, all of the loci are highly polymorphic, with six to 24 alleles per locus across the species range and expected heterozygosity ranging from 0.48 to 0.90 per locus within a sample of 24 rats from a large population on Kangaroo Island. Cross‐species amplification rates were approximately 87% within the Australian Rattus and approximately 50% within R. rattus and R. norvegicus. These loci are highly polymorphic with a high success rate of cross‐species amplification, making them potentially useful for a wide range of genetic studies.     

A Genome Scan and Linkage Disequilibrium Analysis among Chromosomal Races of the Australian Grasshopper Vandiemenella viatica

In the past decade the interest surrounding the role of recombination in speciation has been re-kindled by a new generation of chromosomal speciation models that invoke the recombination-suppression properties of some types of chromosomal rearrangement. A common prediction of recombination-suppression models is that gene exchange between diverging populations will be more restricted in regions of the genome that experience low recombination. We carried out a genome scan of three chromosomal races of the grasshopper Vandiemenella viatica (Orthoptera: Morabinae), occurring on Kangaroo Island, South Australia, using 1517 AFLP loci, with a view to elucidating the roles that selection and chromosomal variation have played in the formation of these taxa. An analysis of molecular variance demonstrated that chromosomal race accounted for a significant proportion of the genetic variance in the total dataset, which concurred with the findings of an earlier study. Sampling across one previously-identified hybrid zone, and the identification of outlier loci between parental races allowed us to establish that, in admixed populations, outlier loci which potentially pre-date the isolation of populations of races on Kangaroo Island exhibit higher levels of linkage disequilibrium with each other than putatively neutral loci. In turn this suggests that they might reside within genomic regions of low recombination, or be closely linked with each other.     

Vocal Discrimination in Mate Guarding Male Australian Sea Lions: Familiarity Breeds Contempt

The vocal characteristics of a species can be immensely diverse, and can significantly impact animal social interactions. The social structure of a species may vary with geographical variation in call characteristics. The ability of pinnipeds (true seals, fur seals, sea lions and walrus) to distinguish between conspecifics may assist male reproductive strategies, particularly mate acquisition. We assessed the ability of mate guarding Australian sea lion (Neophoca cinerea) males to discriminate local from foreign males’ barks recorded from a geographically distant breeding colony. Bark characteristics were significantly different between colonies, with barks produced by males from the Lewis Island breeding colony higher pitched and longer in both duration and interval duration than barks produced by males on Kangaroo Island. Mate guarding males displayed inter‐colony discrimination of barks, with a significantly stronger response to barks from local males than to those of males from a colony approx. 180 km away. Local males’ barks were apparently considered a greater threat than barks from unfamiliar males. We propose that discrimination of acoustic characteristics may facilitate reproductive isolation in this species that may lead to an ethological–acoustic barrier between breeding colonies, and subsequent genetic isolation.