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31.
Elena GANGENOVA Mariano I. GIOMBINI Gustavo A. ZURITA Federico MARANGONI 《Integrative zoology》2020,15(5):428-440
Species loss by habitat replacement operating as an ecological filter is a well‐known consequence of modern human activities. In contrast, the ecological and evolutionary response of species overcoming those filters in converted habitats has not been thoroughly explored. Species that persist are subject to novel and potentially stressful conditions that may induce certain morphological changes. We evaluated changes in the functional morphology of three anuran species persisting after the conversion of areas of the Atlantic Forest into pine plantations. We specifically evaluated differences in body size and body condition indices, head width, and hind legs’ length between adult individuals from both habitats and sexes. Habitat conversion and sexual dimorphism affected the morphology of the three anurans, with varying effects upon species and traits. Regarding the effect of habitat conversion, Elachistocleis bicolor increased body condition in plantations with no changes in the other traits, Physalaemus cuvieri showed only a marginal increment in residual body mass in plantations, and Odontophrynus americanus exhibited a substantial increment in body size while maintaining its body condition in plantations. Remarkably, none of the results suggested these persistent anurans were stressed by forest conversion. This study shows that habitat conversion may induce intraspecific morphological changes in ecologically relevant traits of persistent species, and that disturbed areas do not necessarily imply stressful, low quality habitats affecting all persistent native species negatively. 相似文献
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为分析广西5个自然保护区两栖动物的多样化程度,监测保护区的生态环境质量,根据广西5个自然保护区的两栖动物名录,通过物种组成比较并运用G-F指数进行科属阶元的多样性测度分析,结果表明:元宝山、猫儿山、岑王老山、弄岗、龙滩自然保护区的两栖动物G指数(DG)、F指数(DF)、G-F 指数(DG-F)分别为2.8144、3.9577、0.2889、2.8521、3.9831、0.2840、2.5709、3.5835、0.2826、2.5383、3.4516、0.2469,2.2481、2.2691、0.0093、较好地反映出广西5个自然保护区的两栖动物的科属阶元的多样性程度,为保护区的生物多样性保护与建设提供了依据。 相似文献
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Wild‐Caught and Farm‐Reared Amphibians are Important Reservoirs of Salmonella,A Study in North‐East Thailand
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The role of amphibians as Salmonella reservoirs has not been as well studied as in reptiles, where the literature is abundant. Recent outbreaks of salmonellosis associated with exotic pet frogs have occurred in United States. Frog farming and wild frog harvesting have increased the international trade in these species. This necessitates a better understanding of the risk of salmonellosis transmission from amphibians to humans. We explored the presence of Salmonella in amphibians (frogs and toads) in Thailand, where farmed and wild frogs as well as toads are present. These live animals are easily found in the local markets and are used as food. Exportation of frog meat from Thailand is common. During March–June 2014, ninety‐seven frogs were collected from several habitats, including frog farms, urban areas and protected natural areas. The collected amphibians were tested for the presence of Salmonella. The overall prevalence of Salmonella was 69.07% (90.00% in farm animals, 0% in urban area animals and 44.83% in protected area animals). Eight serovars of Salmonella were isolated: subsp. diarizonae ser. 50:k:z, Hvittingfoss, Muenchen, Newport, Stanley, Thompson, Panama and Wandsworth. Six of the identified serovars, Hvittingfoss, Newport, Panama, Stanley, Thompson and Wandsworth, have been detected in humans in Thailand. According to our results, amphibians are reservoirs of Salmonella and can be a public health concern when used as a source of protein for humans. 相似文献
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Amphibians are commonly used in biomedical research, including studies of mechanisms of anaesthetic action. There is, however,
little published work describing the kinetics of inhaled anaesthetic agents or the potency of isoflurane in amphibians. Ten
Northern leopard frogs were exposed to a constant isoflurane concentration of 1.0%, 1.2% or 1.5% atm for 4 h, and their response
to a noxious stimulus was tested every 20 min. Each frog was anaesthetized with each concentration in random order and allowed
at least 16 h to recover between anaesthetic exposures. Frogs were then pithed and the protocol was repeated. Frogs first
displayed immobility during stimulus application at 80 min, and the proportion of animals becoming immobile steadily increased
to reach a stable level at 4 h. The 50% effective dose for isoflurane in intact and pithed frogs did not differ, and was 1.15
and 1.25% atm, respectively. The potency of isoflurane in leopard frogs was similar to that reported in mammalian species.
Cutaneous uptake of anaesthetic is effective given sufficient time, approximately 4 h in this study. Forebrain structures
appear to be unimportant for the immobilizing action of isoflurane in the frog. 相似文献
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Noelia V. Gonzalez Baffa‐Trasci Laura C. Pereyra Mauricio S. Akmentins Marcos Vaira 《水产资源保护:海洋与淡水生态系统》2020,30(7):1437-1450
- Modification and loss of natural habitats caused by human activities are among the main drivers of biodiversity decline worldwide. To evaluate how land‐use changes affect species diversity at different spatial scales, amphibians represent an excellent group given that their complex life cycle requires both aquatic and terrestrial habitats.
- In this study, the influence of wetland characteristics and surrounding landscape features on richness and functional diversity of anurans was investigated in 26 natural wetlands in a human‐modified landscape within the Southern Andean Yungas.
- The analysis was performed at two spatial scales: wetland scale (the breeding pond structure) and the surrounding landscape scale. The classification of the landscape was limited to land uses modified by human activities within concentric circular buffers (radius = 0.1, 0.2, 0.5, and 1 km) centred on each breeding pond.
- Generalized linear models were applied to investigate the relationship between environmental variables measured at different scales and anuran species richness and functional diversity, respectively.
- Pond area best explained the observed variation in both diversity measures, which is consistent with other studies on anuran diversity in disturbed landscapes. In contrast to regression models including landscape scale variables only, integrated models (which included variables on both scales) highly improved model fit.
- Conservation strategies for anuran species diversity in these altered Andean Yungas forests should include efforts to maintain or restore aquatic habitats (e.g. breeding ponds) placed within suitable landscapes.
- Successful long‐term management will require an understanding of relationships between habitat characteristics at different spatial scales to identify variables that relate to species diversity in such heterogeneous habitats.
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《Journal of Exotic Pet Medicine》2014,23(1):50-55
This review covers recent developments in the field of amphibian therapeutics without repeating previous extensive clinical reviews, formularies, and compendia. The information provided in this article would aid the veterinary practitioner treating amphibian species through the use of updated clinical therapeutic techniques and dosages. 相似文献
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Anastasios Bounas Maria Keroglidou Elisavet‐Aspasia Toli Ieremias Chousidis Dimitris Tsaparis Ioannis Leonardos Konstantinos Sotiropoulos 《水产资源保护:海洋与淡水生态系统》2020,30(5):1037-1049
- Freshwater communities and especially pond‐breeding amphibians are extremely vulnerable to land‐use change, alien species introductions and the use of pesticides or other toxic chemicals, as reflected in their worldwide decline. Effective conservation and management of ponds requires a better understanding of the biotic and abiotic factors that shape diversity patterns and species distribution, especially in cases of habitat loss
- The present study aimed to reveal and classify which pond and landscape characteristics are the most important determinants for the occurrence patterns of amphibian species as well as for the overall amphibian species richness in an urban pond network. To achieve this aim, 17 biotic and abiotic variables were measured for 61 ponds and the dataset was analysed by means of a machine‐learning approach, suitability indices and co‐occurrence modelling
- The highest probability of Triturus macedonicus occurrence was found at fishless artificial and semi‐natural ponds. The persistence of Lissotriton graecus in ponds was predicted by high pond connectivity and the absence of fish reflecting the species dispersive potential. Pelophylax kurtmuelleri showed a higher probability of occurrence with increased pond connectivity and macrophyte cover.
- Amphibian species richness was higher in fishless ponds with well‐oxygenated waters located in sites with a low to intermediate road density network. Ponds categorized as ‘average’ in terms of newt suitability were more frequently inhabited by fish than Triturus macedonicus. Alien fish species showed negative associations with both newt species, while both newt species showed a positive association between them.
- The results support the view that conserving a greater number of water bodies with increased landscape connectivity and without any fish presence could provide amphibian species with alternative habitat choices, especially in sites with human pressure where pond stability is at stake owing to continuous landscape changes.