Academic literature on the topic 'Ceratophysella sigillata'

A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as sigillin A from Ceratophysella sigillata.

AbstractThe study compared communities of soil Collembola along the inversed microclimatic gradient of the collapse doline of the Silicka ľadnica Ice Cave (Slovakia) in spring and autumn of 2005. Kruskal-Wallis ANOVA and the Mann- Whitney test revealed significant differences in abundance between sites and both seasons. Significantly higher abundance means and species richness were observed at most sites during the spring compared with the autumn. NMS ordination documented a clear delimitation of communities with remarkably different soil microclimates. The community pattern of the coldest section of the gradient, with low species richness and high mean abundance, was analogous to communities living in the harsh alpine and polar soils. The collapse doline with inversed microclimate hosted a high number of species (72) and a broad variety of montane forms (13), thus documenting that these karst landforms enhance local diversity of edaphic Collembola and serve as local refugia of specialized cold-tolerant species. The cold tolerance of the four abundant species at the doline cold sites, namely Ceratophysella sigillata, Tetrodontophora bielanensis, Protaphorura armata and Desoria tigrina, was tested in the laboratory using one-hour exposition survival tests. Within a temperature range from -2.4 to -7.8◦C, T. bielanensis was the most cold-sensitive species, with a lethal dose LD50 of -4.4◦C, while D. tigrina was the most cold-resistant, showing LD50 of -5.8◦C.

We hypothesized that trogloxenes inhabiting surface habitats, thermally fluctuating environment, would tolerate wide temperature ranges. We expected that the temperature tolerances would diminish over categories trogloxene - subtroglophile - eutroglophile - troglobiont as a result of the degree of adaptation to subterranean environment that is characteristic with thermally stable conditions. We also assumed that body size may play crucial role in tolerance of Collembola to high and low temperature. Eighteen species of all four categories were exposed to one-hour survival laboratory test. The impact of temperature, species and species-temperature interaction on the cold and heat survival was statistically significant. The species heat tolerance significantly increased with increasing cold tolerance. In general, decrease in cold and heat tolerance was shown from trogloxenes, over subtroglophiles and eutroglophiles to troglobionts. Cryptic species Folsomia sp. among trogloxenes and Ceratophysella sigillata, Hypogastrura crassaegranulata among subtroglophiles were highly heat- and also cold-resistant, showing wide ecological plasticity. Subtroglophilous Tetrodontophora bielanensis and Lepidocyrtus violaceus , eutroglophilous Heteromurus nitidus and troglobiont Protaphorura janosik were the most cold-sensitive species, and all troglobionts and eutroglophilous Pygmarrhopalites pygmaeus as the most heat-sensitive species. Species belonging to ecological groups not or less associated to cave environment (trogloxenes and subtroglophiles) showed wider range of temperature tolerance in comparison with more cave adapted species (eutroglophiles and troglobionts), tested by ANOVA. Cold resistance decreased significantly with increasing body length, indicating that body size plays an important role in temperature tolerances of arthropods inhabiting soil and subterranean habitats.

Resumo Este trabalho, com vista à obtenção de grau de Mestre em Gestão Ambiental, teve dois objetivos principais. O primeiro objetivo foi avaliar a comparabilidade entre a sensibilidade de organismos de culturas de laboratório de Folsomia candida da Universidade de Coimbra e a sensibilidade de organismos da mesma espécie recolhidas em campo (culturas de campo). Para isso, recorreu-se à realização de ensaios de reprodução com F. candida de culturas de laboratório e de campo utilizando um gradiente de solos contaminados com cobre, Montana (s.a. glifosato) e Dursban (s.a. clorpirifos). Foi utilizado para o efeito um solo agrícola natural como substrato e foram usados indivíduos da espécie F. candida recentemente recolhidos na mesma área onde o solo foi extraído. Foi observada uma toxicidade semelhante ao cobre e à s.a. clorpirifos entre os colêmbolos de laboratório e de campo. Contudo, os colêmbolos das culturas de laboratório mostraram maior sensibilidade à s.a. glifosato que os das culturas de campo. O segundo objetivo consistiu em estudar os ciclos de vida das espécies Arrhopalites caecus e Ceratophysella sigillata – espécies de diferentes extractos do solo – e avaliar a viabilidade do seu uso em ensaios laboratoriais de reprodução. Para isso procedeu-se à avaliação dos “parâmetros temporais” considerados importantes para a sincronização das espécies e para a definição do período teste mais adequado nos ensaios de reprodução. Foi também avaliada a eficiência de diferentes técnicas de extracção dos colêmbolos (adultos e juvenis) para terminar os ensaios de reprodução. Quanto aos resultados obtidos referentes à espécie A. caecus, os parâmetros temporais medidos evidenciaram valores muito semelhantes aos reportados na literatura. Já quanto à forma de extracção de colêmbolos, verificou-se que é viável usar o mesmo método usado nos ensaios de reprodução com F. candida. Relativamente à espécie C. sigillata, os parâmetros temporais medidos foram em geral mais curtos do que os reportados na literatura. Já no que toca ao método de extracção, verificou-se que a metodologia mais adequada foi a que é usada nos ensaios de reprodução com os ácaros Hypoaspis aculeifer. Palavras-chave: Folsomia candida; ensaios de reprodução; Arrhopalites caecus; Ceratophysella sigillata. Abstract This work aimed at obtaining the Master degree in Environmental Management and had two main objectives. The first objective was to evaluate the comparability between the sensitivity of Folsomia candida individuals from laboratory cultures of the University of Coimbra and the sensitivity of individuals from the same species but recently collected from the field. For that purpose, laboratory reproduction tests with F. candida from laboratory cultures (lab cultures) and F. candida recently collected from the field (field cultures) were performed, using a gradient of spiked soils with increasing concentrations of copper, Montana (a.i. glyphosate) and Dursban (a.i. chlorpyrifos). A natural agricultural soil collected in the same area where F. candida from field cultures were collected, was used as substrate. Copper and chlorpyrifos showed similar toxicities to both individuals of F. candida from lab and field cultures. However, collembolans from lab cultures showed higher sensitivity to glyphosate compared to that showed by collembolans from field cultures. The second objective consisted on studying the life cycles of the Arrhopalites caecus and Ceratophysella sigillata species - species from different soil layers - and evaluating their viability to be used in laboratory reproduction tests. For that purpose, the “temporal parameters” considered important to the species synchronization and to define the most adequate time period for laboratory reproduction tests, were investigated. The most efficient method to extract collembolans (adults and juveniles) at the end of the tests was also evaluated. Concerning the results obtained for A. caecus, the temporal xiii parameters measured in this study evidenced values similar to those reported in the literature. For the extraction method, the method usually adopted to extract collembolans at the end of F. candida reproduction tests was the most suitable. Regarding C. sigillata specie, temporal parameters measured were generally shorter than those reported in the literature. Regarding extraction method, the method generally adopted to extract mites in reproduction tests with the mite Hypoaspis aculeifer was the one that showed higher adequacy for C. sigillata. Palavras-chave: Folsomia candida lab; Folsomia candida field; reprduction tests; Arrhopalites caecus; Ceratophysella sigillata.