26 resultados para Crustacea - Geographical distribution

em Deakin Research Online - Australia


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The atmospheric quality and distribution of heavy metals were evaluated throughout a wide region of Argentina. In addition, the biomonitor performance of Tillandsia capillaris Ruiz & Pav. f. capillaris was studied in relation to the accumulation of heavy metals and to its physiologic response to air pollutants. A sampling area of 50,000 km2 was selected in the central region of the Argentine Republic. This area was subdivided into grids of 25 x 25 km. Pools of T. capillaris, where present, were collected at each intersection point. From each pool three sub-samples were analyzed independently. Furthermore, five replicates were collected at 20% of the points in order to analyze the variability within the site. The content of Co, Cu, Fe, Ni, Mn, Pb and Zn was determined by Atomic Absorption Spectrometry. Chemical-physiological parameters were also determined to detect symptoms of foliar damage. Chlorophylls, phaeophytins, hydroperoxy conjugated dienes, malondialdehyde and sulfur were quantified in T. capillaris. Some of these parameters were used to calculate a foliar damage index. Data sets were evaluated by one-way ANOVA, correlation analysis, principal component analysis and mapping. Geographical distribution patterns were obtained for the different metals reflecting the contribution of natural and anthropogenic emission sources. According to our results it can be inferred that Fe, Mn and Co probably originated in the soil. For Pb, the highest values were found in the mountainous area, which can be attributed to the presence of Pb in the granitic rocks. Ni showed mainly an anthropogenic origin, with higher values found in places next to industrial centers. For Zn the highest values were in areas of agricultural development. The same was observed for Cu, whose presence could be related to the employment of pesticides. The foliar damage index distribution map showed that the central and southeastern zones were the ones where the major damage in the bioindicator was found. The central zone coincides with the city of Córdoba whereas the southeastern area is strictly agricultural, so the high values found there could be related to the use of pesticides.

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A global review of the stratigraphical and geographical distribution of Tyloplecta reveals that the genus ranges in age from Kungurian to Changhsingian (Middle to Late Permian). Tyloplecta first evolved in South China in the Kungurian (late Early Permian). The genus went through its first diversification in the Guadalupian, suffered a major extinction at the end of the Guadalupian, and re-diversified in the Wuchiapingian. T. yangtzeensis persisted into the Changhsingian as the only survivor of the genus involved in the end-Permian mass extinction. Palaeogeographically, South China is not only the centre of origin for the genus but also an area of diversification and evolution. In addition to South China, Tyloplecta has also been recorded from the Far East Russia, Japan, central Thailand, Laos, Cambodia, Qiangtang Terrane of Tibet, Salt Range, Iran, Armenia, Hungary, Yugoslavia, and Slovenia. This geographic spread suggests that Tyloplecta was primarily restricted to the Palaeotethys and is indicative of warm-water palaeoequatorial conditions. Its presence in some of the northeast Asian terranes (e.g., parts of Japan and Far East Russia) and in the Salt Range (Pakistan) and central and north Iran (part of the Cimmerian microcontinents) demonstrate that the genus invaded the middle palaeolatitudinal regions in both hemispheres during the late Middle Permian in response to increased shallow marine biotic communications between Cathaysia in the eastern Palaeotethys and southern Angaraland, and between Cathaysia and Peri-Gondwanaland. The invasion of Tyloplecta (and some other taxa) into the southern shore waters of Angaraland may be explained by assuming ocean surface current connections and close palaeogeographical proximities between the South China, Sino-Korea and Bureya blocks. In comparison, the invasion of Tyloplecta into the Peri-Gondwanaland region is more likely a result of reduced palaeogeographical distance between South China and Peri-Gondwanaland and the appearance of the Cimmerian microcontinents as migratory stepping stones.

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This study describes the investigation of postgraduate students of mixed age and gender distributed across several Australian states as well as off shore who were juggling study with workplace demands. As face to face meeting was impossible because of the geographical distribution of the group members and because the course communication was centred on an online conference space, a small group space was established for each group for the purpose of completing the problem-based learning task. This paper provides a detailed description of the group dynamics and interactive processes required to negotiate an online problem-based learning task. It will also suggest ways to improve the collaborative learning potential of the online environment through well structured and meaningful activities.

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Two new species of gall midge associated with two distinct galls on the succulent creeping shrub Sarcocornia quinqueflora are described from salt marshes in south-eastern Australia. The infestations caused by the new species hinder the growth of S. quinqueflora, the seeds of which are the major food of the critically endangered orange-bellied parrot Neophema chrysogaster. Asphondylia floriformis sp. n. Veenstra-Quah & Kolesik transforms leaf segments into flower-like galls, whereas Asphondylia sarcocorniae sp. n. Veenstra-Quah & Kolesik produces simple swellings on branches. Both galls have fungal mycelium growing in the apoplast of the gall tissue and lining the inner surface of the larval chamber where it is presumably grazed by the larva. Descriptions of the larvae, pupae, males, females and the geographical distribution of the two gall midges in south-eastern Australia are given.

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Two new marine nematode species are described from intertidal sediments in southern New Zealand. Setosabatieria australis sp. nov. is characterised by an amphideal fovea with 3.5 turns, 7–9 small pre-cloacal supplements, and 2–5 sub-cephalic setae per file. Setosabatieria australis sp. nov. differs from all known species of the genus in having L-shaped spicules with a hollow median region, in contrast to the typical curved shape. Desmolaimus courti sp. nov. is characterised by the presence of four long (15 µm) cephalic setae, two cuticularised rings in the buccal cavity, and a lightly cuticularised pharyngeal lumen. It differs from other species of the genus by having eight sub-cephalic setae. A total of 116 marine species are included in the checklist of New Zealand free-living nematodes, with the majority of records from the coast of Campbell and Auckland islands from the early part of the 20th century. Most records were from habitats such as seaweed or sponge, which may explain the high proportion (>50%) of cosmopolitan species recorded in New Zealand to date. Little is known about the sediment nematode fauna, particularly in deeper waters (>120 m), from where there are no records to date.

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Locust outbreaks provide an abundant, but unpredictable food source for many native species in Australia. For economic reasons, locust control is unavoidable and can affect a considerable area in Eastern Australia. Depending on the pesticide applied, locust control operations may affect birds in treated areas, either directly through intoxication of the predator, or indirectly, through elimination of its prey. As a preliminary step in identifying the potential impact of these operations on native species, the co-occurrence of birds and locust control operations was assessed using GIS mapping techniques. Data from the Birds of Australia New Atlas provided information about species' distribution between latitudes 17 and 37 degree S, and longitudes 136 and 152 degree E. Of the 834 species present in this region, 292 were chosen on the basis of their geographical distribution and occurrence west of the Great Dividing Range. Sightings for each species were mapped using reporting rates and number of observations per half-degree grid cells. Birds were categorised by habitat, distribution, movement and feeding habits and those species reported to consume Orthopterans were noted. APLC locust survey (1987–2000) and spraying data (1977–2002) were analysed and overlapped with soil and vegetation maps obtained from Geoscience Australia and Environment Australia to find significant hotspots for locust occurrence. These maps were then overlayed with bird distributions to identify the species most likely to be in areas of locust presence and spraying operations.

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The study investigated fish community characteristics in relation to environmental characteristics and impacts of introduced fish species in basins within Victoria and New South Wales, Australia. A wide variety of environmental characteristics influenced fish distributions over the area investigated including biogeography, land and water exploitation, basin size and morphology.

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Molecular genetic date was used to test the taxonomic hypothesis of a single species of the freshwater shrimp, Paratya australiensis. While the results identified significant cryptic diversity, clear species boundaries could not be defined. The results of this study defy a simple taxonomic conclusion but are suggestive of incipient speciation.

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Since April 2001 we have been monitoring the Subjective Wellbeing (SWB) of the Australian population using the Personal Wellbeing Index. Our aims are to establish normative values and to identify people with abnormally low SWB. Each of 18 surveys has involved a new sample of 2,000 people, randomly chosen but representing the geographical distribution of the population. The data are remarkable for their stability, with the variation in population mean scores being just 3.2 percentage points. The cause of such high reliability is Subjective Wellbeing Homeostasis. Here, in a manner analogous to the management of body temperature, the SWB for each person is normally held positive and within a narrow set-point range. However, all homeostatic systems have a limited capacity to absorb challenge and when aversive experiences are both strong and sustained, homeostasis fails. If this occurs, people lose their normal positive view of themselves and become depressed. Therefore, the second aim of these studies is to reveal the demographic character of families in distress, who are in need of additional resources. Our data reveal the extent to which family structure and responsibilities impact on wellbeing. They also yield important diagnostic information about individuals, and point to SWB as a crucial measure of intervention outcome. In sum, the Personal Wellbeing Index is a simple, reliable and valid measure of SWB. The measures it yields are theoretically embedded, they can be compared against solid normative data, and their interpretation is enhanced through an understanding of SWB homeostasis.

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Studies of Australian rock coasts (except carbonate reefs) are reviewed and considered in view of recent process and morphological studies. The unique nature of the Australian coast, its geographical distribution and relative stability mean that it is a productive environment in which to research fundamental questions concerning rock coasts. Future research directions are identified, specifically in the areas of processes, morphology and modelling.

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Migrants, such as birds or representatives of other taxa, usually make use of several stopover sites to cover the distance between their site of origin and destination. Potentially, multiple routes exist, but often little is known about the causes and consequences of alternative migration routes. Apart from their geographical distribution, the suitability of potential sites might play an important role in the animals’ decisions for a particular itinerary. We used an optimal-migration model to test three nonmutually exclusive hypotheses leading to variations in the spring migration routes of a subspecies of Red Knot, Calidris canutus islandica, which migrates from wintering grounds in Western Europe to breeding grounds in Greenland and the Canadian Arctic: the breeding location hypothesis, the energy budget hypothesis, and the predation risk hypothesis. Varying only breeding location, the model predicted that birds breeding in the Canadian Arctic and on West Greenland stop over on Iceland, whereas birds breeding in East and Northeast Greenland migrate via northern Norway, a prediction that is supported by empirical findings. Energy budgets on stopover sites had a strong influence on the choice of route and staging times. Varying foraging-intensity and mass-dependent predation risk prompted the birds to use less risky sites, if possible. The effect of simultaneous changes in the energy budget and predation risk strongly depended on the site where these occurred. Our findings provide potential explanations for the observations that C. canutus islandica uses a diverse array of migration routes. Scrutinizing the three alternative driving forces for the choice of migratory routes awaits further, specific data collection in rapidly developing fields of research (e.g., predation risk assessment, GPS tracking). Generally, the type of modeling presented here may not only highlight alternative explanations, but also direct follow-up empirical research.

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Lithostratigraphy, biostratigraphy of the Ordovician Xainza area, northern division and correlation divided of approximates of the early as of Ordovician of Tetragraptus (Paratetragraptus)-Didymograptus (Corymbograptus) deflexus combination of Middle Ordovician Michelinoceras elongatum- combination with Sinoceras chinese and the Late Ordovician Michelinoceras huangnigang-Columenoceras priscum combination band. Early Ordovician strata author from 2000 to 2001 making Xainza County Sheet 1:250000 regional geological survey newly discovered, is the oldest strata of reliable fossils based in northern Tibet. Especially Tetragraptus (Paratetragraptus) approximatus discovery, not only to expand the distribution of it in our geographic area Early Ordovician strata the similar stratigraphic correlation international biological basis.

The paper deals with the classification and correlation of lithostratigraphy and biostratigraphy of the Ordovician System in the Xainza region, North Tibet. Based on fossils, the Ordovician System is divided into several biozones as follows: Tetragraptus (Paratetragraptus) approximatus Didymograptus (Corymbograptus) deflexus graptolite assemblage of Early Ordovician, The sediments of Early Ordovician is discovered recently by authors during 2000~2001 when making the geological surveying 1:250000 scale of Xainza county, Which has been the oldest stratum based on fossils up to now in northern Tibet. What is more, the discovery of Tetragraptus (Paratetragraptus) approximatus enlarges its geographical distribution in our nation as well as provides biology evidence to international correlation of the Ordovician in Xainza county.

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Eastern Taerma bridge-Zhakang was found in recent years to be the second spot of Ordovician outcrop based on reliable fossils. The nautiloids described here include one new genus, two new species and one indeterminate species,which represent only a small fraction of the nautiloids collected from this area. They are new materials of Ordovician nautiloids that have been determined up to now, which enrich Ordovician nautiloid faunal assemblages as well as provide new data to both classification and correlation of the Ordovician for this area and geographical distribution of nautiloid fauna.