The diversity of the Digenea of Australian animals

The Digenea is one of five major helminth assemblages represented in Australian animals. History of the study of digeneans in Australia is reviewed briefly to show that it has never been subjected to the kind of sustained study needed to reach an understanding of it. The Australian vertebrate fauna comprises over 5500 species. These have so far been shown to harbour just over 70 families, about 306 genera and 566 species of digeneans. Digeneans occur in all classes of vertebrates in Australia but are distributed very unevenly; aquatic hosts are generally most heavily infected, but many terrestrial species are also infected. Particular weaknesses in knowledge of the fauna concern the bats, cetaceans and teleosts. Another weakness is in knowledge of life-cycles; representative life-cycles are known for only about 20 of the 70 families known in Australia. Estimates of the overall size of the fauna are dependent on an understanding of sampling strategies, the heterogeneity of distribution of the fauna, and the nature of host-specificity. These subjects are reviewed briefly and an estimate of the total fauna is made. There may be as many as 6000 species of digeneans in Australia. (C) 1998 Australian Society for Parasitology. Published by Elsevier Science Ltd.

Bird responses at inherent and induced edges in the Murray Mallee, South Australia. 1. Differences in abundance and diversity

We quantified differences in the abundance and diversity of bird species at inherent (naturally occurring) and induced (human-created) edges in the Murray Mallee, South Australia, to explore the effects of anthropogenic landscape modification. Bird species were classified into edge response categories based on numerical differences in abundance between the edge and interior of habitat patches. 'Open-country' species (e.g. Australian Magpie and Little Raven) increased in abundance near induced edges, but were rarely recorded > 200 m into patch interiors or at inherent edges. The Australian Ringneck, Red Wattlebird, Spiny-cheeked Honeyeater, Singing Honeyeater and White-eared Honeyeater increased in abundance near each inherent edge and were classified as 'edge-users'. However, their responses at induced edges varied between sites. The Yellow-plumed Honeyeater, Spotted Pardalote, White-browed Babbler, Chestnut Quail-thrush and Southern Scrub-robin decreased in abundance near one or more induced edges and were classified as 'edge-avoiders' at these sites. The Yellow-plumed Honeyeater, Spotted Pardalote, Chestnut Quail-thrush and Southern Scrub-robin are considered mallee habitat specialists in eastern Australia. These species may be particularly affected by anthropogenic modification of mallee vegetation.

Prediction of rock alteration patterns: a potential tool in mineral exploration

Hydrothermal alteration of a quartz-K-feldspar rock is simulated numerically by coupling fluid flow and chemical reactions. Introduction of CO2 gas generates an acidic fluid and produces secondary quartz, muscovite and/or pyrophyllite at constant temperature and pressure of 300 degrees C and 200 MPa. The precipitation and/or dissolution of the secondary minerals is controlled by either mass-action relations or rate laws. In our simulations the mass of the primary elements are conserved and the mass-balance equations are solved sequentially using an implicit scheme in a finite-element code. The pore-fluid velocity is assumed to be constant. The change of rock volume due to the dissolution or precipitation of the minerals, which is directly related to their molar volume, is taken into account. Feedback into the rock porosity and the reaction rates is included in the model. The model produces zones of pyrophyllite quartz and muscovite due to the dissolution of K-feldspar. Our model simulates, in a simplified way, the acid-induced alteration assemblages observed in various guises in many significant mineral deposits. The particular aluminosilicate minerals produced in these experiments are associated with the gold deposits of the Witwatersrand Basin.

Petrographic and isotope constraints on the origin of authigenic carbonate minerals and the associated fluid evolution in Late Permian coal measures, Bowen Basin (Queensland), Australia

Authigenic carbonate minerals are ubiquitous throughout the Late Permian coal measures of the Bowen Basin, Queensland, Australia. In the northern Bowen Basin, carbonates include the following assemblages: siderite I (delta O-18(SMOW) = +11.4 to + 17%, delta C-13(PDB) = - 5.3 to + 120), Fe-Mg calcite-ankerite-siderite II mineral association (delta O-18(SMOW) = +7.2 to + 10.20, delta C-13(PDB) = 10.9 to - 1.80 for ankerite) and a later calcite (delta O-18(SMOW) = +5.9 to + 14.60, delta C-13(PDB) = -11.4 to + 4.40). In the southern Bowen Basin, the carbonate phase consists only of calcite (delta O-18(SMOW) = +12.5 to + 14.80, delta C-13(PDB) = -19.4 to + 0.80), where it occurs extensively throughout all stratigraphic levels. Siderite I occurs in mudrocks and sandstones and predates all other carbonate minerals. This carbonate phase is interpreted to have formed as an early diagenetic mineral from meteoric waters under cold climate and reducing conditions. Fe-Mg calcite-ankerite-siderite Il occur in sandstones as replacement of volcanic rock fragments. Clay minerals (illite-smectite, chlorite and kaolinite) postdate Ca-Fe-Mg carbonates, and precipitation of the later calcite is associated with clay mineral formation. The Ca-Fe-Mg carbonates and later calcite of the northern Bowen Basin are regarded as having formed as a result of hydrothermal activity during the latest Triassic extensional tectonic event which affected this part of the basin, rather than deep burial diagenesis during the Middle to Late Triassic as previously reported. This hypothesis is based on the timing relationships of the authigenic mineral phases and the low delta O-18 values of ankerite and calcite, together with radiometric dating of illitic clays and recently published regional geological evidence. Following the precipitation of the Ca-Fe-Mg carbonates from strongly O-18-depleted meteoric-hydrothermal fluids, continuing fluid circulation and water-rock interaction resulted in dissolution of these carbonate phases as well as labile fragments of volcaniclastic rocks. Subsequently, the later calcite and day minerals precipitated from relatively evolved (O-18-enriched) fluids. The nearly uniform delta O-18 values of the southern Bowen Basin calcite have been attributed to very low water/rock ratio in the system, where the fluid isotropic composition was buffered by the delta O-18 values of rocks. (C) 2000 Elsevier Science B.V. All rights reserved.

Low symbiont diversity in southern Great Barrier Reef corals, relative to those of the Caribbean

The specific identity of endosymbiotic dinoflagellates (Symbiodinium spp.) from most zooxanthellate corals is unknown. In a survey of symbiotic cnidarians from the southern Great Barrier Reef (GBR), 23 symbiont types were identified from 86 host species representing 40 genera. A majority (>85%) of these symbionts belong to a single phylogenetic clade or subgenus (C) composed of closely related (as assessed by sequence data from the internal transcribed spacer region and the ribosomal large subunit gene), yet ecologically and physiologically distinct, types. A few prevalent symbiont types, or generalists, dominate the coral community of the southern GBR, whereas many rare and/or specific symbionts, or specialists, are found uniquely within certain host taxa. The comparison of symbiont diversity between southern GBR and Caribbean reefs shows an inverse relationship between coral diversity and symbiont diversity, perhaps as a consequence of more-rapid diversification of Caribbean symbionts. Among clade C types, generalists C1 and C3 are common to both Caribbean and southern GBR symbiont assemblages, whereas the rest are regionally endemic. Possibly because of environmental changes in the Caribbean after geographic isolation through the Quaternary period, a high proportion of Caribbean fauna associate with symbiont taxa from two other distantly related Symbiodinium clades (A and B) that rarely occur in Pacific hosts. The resilience of Porites spp. and the resistance of Montipora digitata to thermal stress and bleaching are partially explained by their association with a thermally tolerant symbiont type, whereas the indiscriminant widespread bleaching and death among certain Pacific corals, during El Nino Southern Oscillation events, are influenced by associations with symbionts possessing higher sensitivity to thermal stress.

Epidemiological and molecular evidence supports the zoonotic transmission of Glardia among humans and dogs living in the same community

Giardia duodenalis isolates recovered from humans and clogs living in the same locality in a remote tea-growing community of northeast India were characterized at 3 different loci; the SSU-rDNA, elongation factor 1-alpha (ef1-alpha) and triose phosphate isomerase (tpi) gene. Phylogenetic analysis of the SSU-rDNA and ef1-alpha genes provided poor genetic resolution of the isolates within various assemblages, stressing the importance of using multiple loci when inferring genotypes to Giardia. Analysis of the tpi gene provided better genetic resolution and placed canine Giardia isolates within the genetic groupings of human isolates (Assemblages A and B). Further evidence for zoonotic transmission was supported by epidemiological data showing a highly significant association between the prevalence of Giardia in humans and presence of it Giardia-positive dog in the same household (odds ratio 3.01, 95%) CI, 1.11, 8.39, P = 0.0000).

Associated skeletons of a new middle Triassic ""Rauisuchia"" from Brazil

For more than 30 million years, in early Mesozoic Pangea, ""rauisuchian"" archosaurs were the apex predators in most terrestrial ecosystems, but their biology and evolutionary history remain poorly understood. We describe a new ""rauisuchian"" based on ten individuals found in a single locality from the Middle Triassic (Ladinian) Santa Maria Formation of southern Brazil. Nine articulated and associated skeletons were discovered, three of which have nearly complete skulls. Along with sedimentological and taphonomic data, this suggests that those highly successful predators exhibited some kind of intraspecific interaction. Other monotaxic assemblages of Triassic archosaurs are Late Triassic (Norian-Rhaetian) in age, approximately 10 million years younger than the material described here. Indeed, the studied assemblage may represent the earliest evidence of gregariousness among archosaurs, adding to our knowledge on the origin of a behavior pattern typical of extant taxa.

Closely related Symbiodinium spp. differ in relative dominance in coral reef host communities across environmental, latitudinal and biogeographic gradients

The diversity and community structures of symbiotic dinoflagellates are described from reef invertebrates in southern and central provinces of the Great Barrier Reef (GBR), Australia, and Zamami Island, Okinawa, Japan. The symbiont assemblages from region to region were dominated by Clade C Symbiodinium spp. and consisted of numerous host-specific and/or rare types (specialists), and several types common to many hosts (generalists). Prevalence in the host community among certain host-generalist symbionts differed between inshore and offshore environments, across latitudinal (central versus southern GBR) gradients, and over wide geographic ranges (GBR versus Okinawa). One particular symbiont (C3h) from the GBR had a dramatic shift in dominance. Its prevalence ranged from being extremely rare, or absent on high-latitude reefs to dominating the scleractinian diversity on a mid-latitude inshore reef. These changes occurred among coral fauna whose larvae must acquire symbionts from environmental sources (horizontal symbiont acquisition). Such differences did not occur among 'vertical transmitters' such as Porites spp., Montipora spp. and pocilloporids (corals that directly transmit symbionts to their offspring) or among those hosts displaying 'horizontal acquisition', but that associate with specific symbionts. Most host-specialized types were found to be characteristic of a particular geographic region (i.e. Okinawa versus Central GBR versus Southern GBR). The mode of symbiont acquisition may play an important role in how symbiont composition may shift in west Pacific host communities in response to climate change. There is no indication that recent episodes of mass bleaching have provoked changes in host-symbiont combinations from the central GBR.

Molecular characterization of potentially zoonotic isolates of Giardia duodenalis in horses

Giardia isolates from eight horses from New York State (NY), USA and two horses from Western Australia (WA) were genetically characterized at the SSU-rDNA and triose-phosphate isomerase (TPI) genes. Phylogenetic analysis of the TPI gene provided strong support for the placement of both isolates of Giardia from horses in WA and a single isolate from a horse in NY within the assemblage AI genotype of G. duodenalis. Another two isolates from horses in NY placed within the assemblage All genotype of G. duodenalis. Phylogenetic analysis of the TPI gene also provided strong bootstrap support for the placement of four G. duodenalis isolates from horses in NY into a potentially host-specific sub-assemblage of assemblage BIV. The results of this study are consistent with previous studies showing that assemblages AI and AII of G. duodenalis provide the greatest potential zoonotic risk to humans. Horses may therefore constitute a potential source for human infection of Giardia either directly or via watersheds. (c) 2005 Elsevier B.V. All rights reserved.

Seasonal dynamics of a drosophilid (Diptera) assemblage and its potencial as bioindicator in open environments

Drosophila Fallen, 1823 (Diptera, Drosophilidae) is for long a well-established model organism for genetics and evolutionary research. The ecology of these flies, however, has only recently been better studied. Recent papers show that Drosophila assemblies can be used as bioindicators of forested environment degradation. In this work the bioindicator potential of drosophilids was evaluated in a naturally opened environment, a coastal strand-forest (restinga). Data from nine consecutive seasonal collections revealed strong temporal fluctuation pattern of the majority of Drosophila species groups. Drosophila willistoni group was more abundant at autumns, whereas D. cardini and D. tripunctata groups were, respectively, expressive at winters and springs, and D. repleta group at both seasons. The exotic species D. simulans Sturtevant, 1919 (from D. melanogaster group) and Zaprionus indianus Gupta, 1970 were most abundant at summers. Overall, the assemblage structure did not show the same characteristics of forested or urban environments, but was similar to the forests at winters and to cities at summers. This raises the question that this locality may already been under urbanization impact. Also, this can be interpreted as an easily invaded site for exotic species, what might lead to biotic homogenization and therefore can put in check the usage of drosophilid assemblages as bioindicators at open environments.

Composition and diversity of Ephemeroptera (Insecta) nymph communities in the middle section of the Jacui River and some tributaries, southern Brazil

The taxonomic composition and diversity of assemblages of Ephemeroptera nymphs of four lotic environments in the central region of State of Rio Grande do Sul, a subtropical area in southern Brazil, were evaluated. Samplings were done monthly, with a Surber sampler, from June 2001 to May 2002, in the Jacui River and three of its tributaries. The total number of nymphs collected in the four sampling sites was 11,007 in five families and 19 genera, of these, 11 are new records for the State. The highest diversity occurred in Point 4 (H` = 2.41) and the lowest in Point 2 (H` = 1.69). Point 4 had the highest environmental stability, conservation of the riparian vegetation and the lowest anthropic impact, while Point 2 presented a large environmental simplification due to a direct anthropic influence ( e. g. domestic sewerage, trampling by cattle). The diversity of nymphs observed in the total area is high, compared to the estimated maximum theoretical diversity; a result of the high evenness and richness recorded. Rarefaction curves, calculated for a sample of 1,018 specimens, showed a similar expectation of richness for the four sampling sites. This result seems to be associated with the overall environmental homogeneity of the region caused by long-term alterations ( land use and deforestation). In summary, higher diversity of Ephemeroptera nymph assemblages seems to be associated with habitat complexity, a good vegetation cover and a lower anthropic influence.

Species richness, abundance, and body size relationships from a neotropical chironomid assemblage: Looking for patterns

We investigated two of the most studied relationships in the macroecological research program (species richness vs. body size and abundance vs. body size) of a local chironomid assemblage from southeastern Brazil. Although numerous Studies have examined these relationships, few have investigated how they vary at different temporal scales. We used data from a forested stream to document and examine these patterns at monthly intervals. Both the species body size distribution and the abundance-body size relationship varied temporally. In some months the body size distribution was skewed to the right. whereas in others it approached normality. We Found both linear relationships (with different values of slopes). and a polygonal pattern in the abundance-body size relationship. This temporal variation was not related to environmental variables. Our results suggest that body size relationships are temporally instable properties of this chironomid assemblage. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

Introduction: Casting new light on old stones

The purpose of this monograph is to take a new look at various aspects of stone artefact analysis that reveal important and exciting new information about the past. This invovles reorienting our methodological approach to stone artefacts as well as the questions asked of them. The papers making up this volume tackle a number of issues that have long been at the heart of archaeology’s problematic relationship with stone artefacts, including our understanding of the dynamic nature of past stoneworking practices, the utility of traditional classificatory schemes, and ways to unlock the vast amount of information about the strategic role of lithic technology that resides in stone artefact assemblages.

Genotyping of potentially zoonotic Giardia duodenalis from exotic and wild animals kept in captivity in Brazil

We have studied the variability of glutamate dehydrogenase (gdh) and small subunit ribosomal (SSU) rRNA coding genes of Giardia species in fecal samples isolated from wild and exotic animals in Brazil, and compared with homologous sequences of isolates from human and domestic animals characterized in previous studies. Cysts of Giardia duodenalis were obtained from feces of naturally infected monkeys (Alouatta fusca) (n = 20), chinchillas (Chinchilla lanigera) (n = 3), ostriches (Struthio camelus) (n = 2) and jaguar (Panthera onca) (n = 1). Assemblage AI was assigned to the unique isolate of jaguar. All the samples from monkeys, chinchillas, and ostriches were assigned to Assemblage B. There was little evolutionary divergence between the referred isolates and isolates described elsewhere. The Assemblage B isolates identified in this study were closely related to Assemblage BIV isolated from humans. The molecular identification of Assemblages A and B of G. duodenalis isolates from exotic and wild animals demonstrates that such hosts may be a potential reservoir for zoonotic transmission of G. duodenalis. (C) 2011 Elsevier B.V. All rights reserved.

Relations between coal petrology and gas content in the Upper Newlands Seam, central Queensland, Australia

The Upper Newlands Seam in the northern Bowen Basin, Queensland, Australia consists of six benches (A-F) that have different petrographic assemblages. Benches C and E contain relatively abundant inertodetrinite and mineral matter, as well as anomalously high reflectance values; these characteristics support a largely allochthonous, detrital origin for the C and E benches. Fractures and cleats in the seam show a consistent orientation of northeast- southwest for face cleats, and a wide range of orientations for fractures. Cleat systems are well developed in bright bands, with poor continuity in the dull coal. Both maceral content and cleat character are suggested to influence gas drainage in the Upper Newlands Seam. A pronounced positive correlation between vitrinite abundance and gas desorption data suggests more efficient drainage from benches with abundant vitrinite. Conversely, inertinite-rich benches are suggested to have less efficient drainage, and possibly retain gas within pore spaces, which could increase the outburst potential of the coal. (C) 2001 Elsevier Science BN. All rights reserved.