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Pteriid oysters (Pinctada maxima, Pinctada margaritifera, Pinctada albina, Pteria penguin), rock oysters (Saccostrea glomerata, Saccostrea cuccullata, Saccostrea echinata) and representatives of other taxa (Malleidae, Isognomonidae, Pinnidae, Mytilidae, Spondylidae, Arcidae) from the wild, and 4670 hatchery-reared P. maxima, from northern and Western Australia, were examined for parasites and diseases. Rickettsiales-like inclusions and metacestodes of Tylocephalum occurred in most species. Intranuclear virus-like inclusions occurred in 1/415 wild P. maxima, 1/1254 S. cuccullata, 3/58 Isognomon isognomum, 1/80 Pinna bicolor and 1/45 Pinna deltodes. Perkinsus was histologically observed in 1/4670 P. maxima spat, 2/469 P. albina, 1/933 S. glomerata, 16/20 Malleus meridianus, 12/58 I. isognomum, 1/45 P. deltodes, 5/12 Spondylus sp., 1/16 Septifer bilocularis and 3/6 Barbatia helblingii. One of 1254 S. cuccullata was heavily systematically infected with Perkinsus merozoites, meronts and schizonts, and was patently diseased. Other potentially serious pathogens included Haplosporidium sp. in 6/4670 P. maxima spat, Marteilia sydneyi from 1/933 S. glomerata, and Marteilia sp. (probably M. lengehi) (1/1254) and Haplosporidium sp. (125/1254) from S. cuccullata. The latter were associated with epizootics on offshore islands, with heaviest prevalence (45%) in oysters with empty gonad follicles. Marteilioides sp. infected the oocytes of 9/10 female S. echinata from Darwin Harbour. Details of geographical distribution and pathology are given, and the health of the bivalves examined is discussed.  相似文献   

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We present a novel approach to investigating the divergence history of biomes and their component species using single-locus data prior to investing in multilocus data. We use coalescent-based hierarchical approximate Bayesian computation (HABC) methods (MsBayes) to estimate the number and timing of discrete divergences across a putative barrier and to assign species to their appropriate period of co-divergence. We then apply a coalescent-based full Bayesian model of divergence (IMa) to suites of species shown to have simultaneously diverged. The full Bayesian model results in reduced credibility intervals around divergence times and allows other parameters associated with divergence to be summarized across species assemblages. We apply this approach to 10 bird species that are wholly or patchily discontinuous in semi-arid habitats between Australia's southwest (SW) and southeast (SE) mesic zones. There was substantial support for up to three discrete periods of divergence. HABC indicates that two species wholly restricted to more mesic habitats diverged earliest, between 594,382 and 3,417,699 years ago, three species from semi-arid habitats diverged between 0 and 1,508,049 years ago, and four diverged more recently, between 0 and 396,843 years ago. Eight species were assigned to three periods of co-divergence with confidence. For full Bayesian analyses, we accounted for uncertainty in the two remaining species by analyzing all possible suites of species. Estimates of divergence times from full Bayesian divergence models ranged between 429,105 and 2,006,355; 67,172 and 663,837; and 24,607 and 171,085 for the earliest, middle, and most recent periods of co-divergence, respectively. This single-locus approach uses the power of multitaxa coalescent analyses as an efficient means of generating a foundation for further, targeted research using multilocus and genomic tools applied to an understudied biome.  相似文献   

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The EU 2020 Biodiversity Strategy requires the gathering of information on biodiversity to aid in monitoring progress towards its main targets. Common species are good proxies for the diversity and integrity of ecosystems, since they are key elements of the biomass, structure, functioning of ecosystems, and therefore of the supply of ecosystem services. In this sense, we aimed to develop a spatially-explicit indicator of habitat quality (HQI) at European level based on the species included in the European Common Bird Index, also grouped into their major habitat types (farmland and forest). Using species occurrences from the European Breeding Birds Atlas (at 50 km × 50 km) and the maximum entropy algorithm, we derived species distribution maps using refined occurrence data based on species ecology. This allowed us to cope with the limitations arising from modelling common and widespread species, obtaining habitat suitability maps for each species at finer spatial resolution (10 km × 10 km grid), which provided higher model accuracy. Analysis of the spatial patterns of local and relative species richness (defined as the ratio between species richness in a given location and the average richness in the regional context) for the common birds analysed demonstrated that the development of a HQI based on species richness needs to account for the regional species pool in order to make objective comparisons between regions. In this way, we proved that relative species richness compensated for the bias caused by the inherent heterogeneous patterns of the species distributions that was yielding larger local species richness in areas where most of the target species have the core of their distribution range. The method presented in this study provides a robust and innovative indicator of habitat quality which can be used to make comparisons between regions at the European scale, and therefore potentially applied to measure progress towards the EU Biodiversity Strategy targets. Finally, since species distribution models are based on breeding birds, the HQI can be also interpreted as a measure of the capacity of ecosystems to provide and maintain nursery/reproductive habitats for terrestrial species, a key maintenance and regulation ecosystem service.  相似文献   

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The anthocyanin pigments in the fruits of fifty-two species belonging to seventeen families of angiosperms were investigated paper-chromatographicallly. They were identified as cyanidin 3-monoglucoside, pelargonidin 3-monoglucoside, cyanidin 3-rutinoside, pelargonidin 3-rutinoside, cyanidin 3-xylosylglucoside, cyanidin 3-xylosylgalactoside, delphinidin 3-xylosylglucoside and delphinidin 3-sophorosido-5-monoglucoside. Of those anthocyanins detected, the most common was cyanidin 3-monoglucoside. In general, the plants belonging to a certain genus contained the same anthocyanin.  相似文献   

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ObjectivesTo examine the prevalence of bullying behaviours in schoolchildren and the association of bullying with psychological and psychosomatic health.DesignCross sectional survey.SettingGovernment and non-government schools in New South Wales, Australia.Participants3918 schoolchildren attending year 6 (mean age 11.88 years), year 8 (13.96), and year 10 (15.97) classes from 115 schools.ResultsAlmost a quarter of students (23.7%) bullied other students, 12.7% were bullied, 21.5% were both bullied and bullied others on one or more occasions in the last term of school, and 42.4% were neither bullied nor bullied others. More boys than girls reported bullying others and being victims of bullying. Bullying behaviour was associated with increased psychosomatic symptoms. Bullies tended to be unhappy with school; students who were bullied tended to like school and to feel alone. Students who both bullied and were bullied had the greatest number of psychological and psychosomatic symptoms.ConclusionsBeing bullied seems to be widespread in schools in New South Wales and is associated with increased psychosomatic symptoms and poor mental health. Health practitioners evaluating students with common psychological and psychosomatic symptoms should consider bullying and the student’s school environment as potential causes.

Key messages

  • Bullying behaviour occurs in schools worldwide and is likely to be associated with poor health in schoolchildren
  • Research into bullying has been mainly focused on victims but there are other categories of bullying that deserve attention
  • At least three out of five students experienced or participated in bullying in schools in New South Wales, Australia
  • The psychosocial and psychosomatic health of the students varied according to their bullying status
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This study examines the extent to which interactions among two common alpine/subalpine plant species and their neighbours at the Bogong High Plains in southern Australia are characterized by competition or facilitation. The two target species were Celmisia pugioniformis (Asteraceae) and Carex breviculmis (Cyperaceae). Biotic interactions were examined using vegetation removal manipulations over three growing seasons at five sites across the altitudinal range of tall alpine herbfield communities. Observations recorded growth and mortality. Results for C. pugioniformis clearly indicated facilitation as a dominant process across all sites and seasons. Plants that had their neighbours removed tended to perform worse than plants that had their neighbours left intact. Growth observations for Ca. breviculmis were less clear, but again suggested facilitation. Mortality was distinctly higher among Ca. breviculmis individuals that had their neighbours removed relative to those with neighbours left intact. Results collectively suggest the removal of neighbours acts to reduce growth and increase mortality in C. pugioniformis and Ca. breviculmis throughout the altitudinal range of tall alpine herbfields at the Bogong High Plains. Facilitative and competitive interactions need to be recognized in efforts aimed at mitigating climate change‐associated impacts on the ecology of alpine plant communities. The extent to which biotic interactions may exacerbate or buffer abiotic change is difficult to predict, emphasizing the need for ecological monitoring.  相似文献   

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DNA barcode divergence among species and genera of birds and fishes   总被引:1,自引:0,他引:1  
COI DNA barcoding is increasingly recognized as a significant new tool for the recognition and identification of animal species. Here, publicly available barcode data are compiled and analysed for birds (657 species) and fishes (1088 species). The proportion of species that cannot be barcode-distinguished by this marker is approximately 6.4% for birds and 2.1-2.5% for fishes. At all hierarchical taxonomic levels (species, genera, family, order, class), fish show greater mean COI divergence than birds. If two samples are barcode-identical, then for both birds and fishes, the probability that they are from the same species is 98-99%. The probability of conspecificity rapidly drops as divergence increases. At 2% COI divergence, this probability approximates to 1% for birds and 3% for fishes. The apparent difference between birds and fishes might partially reflect currently unrecognized cryptic species complexes in the latter. These probability estimates derive from pooled samples of birds and pooled samples of fishes, and will not apply in all situations. Recently evolved species complexes will have higher proportions of species that are barcode-identical. As barcode data accumulate, more refined statistical analyses will become possible.  相似文献   

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