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Systematics of the Lichen Family Verrucariaceae and Evolution of the Rock-inhabiting Habit within a Group of Ecologically Diverse Fungi (Chaetothyriomycetidae, Ascomycota)Gueidan, Cecile 04 December 2007 (has links)
Verrucariaceae are a family including mostly lichenized species (Verrucariales, Ascomycota). Its current generic classification, which mainly relies on three morphological characters (spore septation, thallus structure, and hymenial algae), has never been subjected to molecular data. Because these characters were suspected to be homoplastic, the monophyly of the genera as currently delimited based on morphology need to be assessed. A three-gene phylogenetic analysis was carried out using three methods (Maximum Parsimony, Maximum Likelihood, and a Bayesian approach) on 83 taxa, selected from 15 genera in Verrucariaceae. Ancestral state reconstructions were undertaken for four characters (spore septation, thallus structure, hymenial algae, and upper cortex structure). The results confirmed that most of the genera were not monophyletic, and that the most recent common ancestor of Verrucariaceae was most likely crustose, lacking hymenial algae, and with simple spores and a pseudocortex. The use of symplesiomorphic traits to define Verrucaria, the largest and type genus for the Verrucariaceae, as well as the non monophyly of the genera Polyblastia, Staurothele and Thelidium, explain most of the discrepancies between the current classification and a classification using monophyly as a grouping criterion. In order to accommodate newly inferred monophyletic groups, existing genera were re-delimited and three new genera were proposed. Recent broad-scale phylogenetic analyses have shown that Verrucariales was sister to Chaetothyriales, an order first known as including mostly saprophytes and opportunistic animal and human parasites. Investigations of fungal communities colonizing rocks in extreme environments have shown that some slow-growing melanized fungi inhabiting bare rock surfaces belonged to the Chaetothyriales. Multigene phylogenetic analyses were carried out using Maximum Likelihood and a Bayesian approach in order to confirm the affiliation of 25 of these rock isolates. Ancestral state reconstructions were then undertaken on two different datasets to look at the evolutionary history of lichenization within Pezizomycotina, and the rock-inhabiting habit within Eurotiomycetes. Results suggest that the ancestor of the lineage including Verrucariales and Chaetothyriales was likely to be an extremotolerant non-lichenized, rock-inhabiting fungus. Virulence factors of opportunistic parasites within Chaetothyriales, such as melanization and meristematic growth, might have primary been adaptations for life in extreme habitats. / Dissertation
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Dinâmica espacial, migração e preferência de micro-hábitat de Aegla longirostri bond-buckup e buckup, 1994 (crustacea, anomura, aeglidae) / Spatial dynamic, migration and microhabitat preference of Aegla longirostri bond-buckup e buckup, 1994 (crustacea, anomura, aeglidae)Baumart, Joele Schmitt 25 February 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Understanding the population dynamic processes is fundamental to access its viability (health). Great part of these processes is closely related to the organism densities in a studied population. These data can reveal how the population is arranged in the environment and, in adverse conditions, it is possible to forecast the occurrence of dispersion/migration. This study aims to investigate some ecological parameters of an Aegla longirostri population, a freshwater anomuran from the southern Brazil: (i) to estimate the population density, (ii) the substrate preference, (iii) the home range and (iv) the possible dispersion patterns. The study site was the first order stream Sanga do Caranguejo, located in the central region of Rio Grande do Sul State, during 2010 and 2011. For population density and dispersion investigation covo traps were used, distributed through the stream, in different times in the year. The study of the substrate preference used PVC gutters covered by mesh and arranged on the stream substrate, with controlled density population; a surber was used for active search in the stream. The home range analysis used radio telemetry techniques. The population size was estimated in 950 individuals in spring and 210 in autumn (estimated according to the Bayesian Method). With respect to the substrate preference, we found that there is an ontogenetic association regarding the choice. The juveniles, in the first development stages, prefer sandy substrates, while adults (males and females) prefer more complex substrates. The estimates of home range of eglids vary between 8,41 to approximately 45,49 linear meters of stream, and these crustaceans showed the local dislocation, once they perform their activities around a specific point in the stream. To finalize, we identified that the juveniles and adults of eglids are active walkers, not being carried by the flow in a passive way as occurs in larvae stage in other crustaceans. Its activities are related to the environment temperature and density of adult males. We believe that the knowledge about the group has increased, however, as it is a complex group, with a rich evolutionary history, much remain to be investigated about these freshwater crustaceans. / A compreensão dos processos de dinâmica populacional é fundamental para se avaliar a viabilidade (saúde) de uma população. Grande parte desses processos estão estreitamente relacionados com a densidade de organismos da população estudada. Estes dados podem revelar como a população está distribuída no ambiente e, em condições de adversidade ambiental, é possível prever a ocorrência de dispersão/migração. Neste estudo, alicerçado nos fatores ecológicos e biológicos do aeglídeo Aegla longirostri foram investigados: (i) estimativa da densidade populacional, (ii) as preferências de substrato, (iii) a área de vida e (iv) os possíveis padrões de dispersão. Este estudo foi conduzido em um riacho de primeira ordem, Sanga dos Caranguejos, que se localiza na região central do Rio Grande do Sul, durante os anos de 2010 e 2011. Nas investigações sobre densidade populacional e dispersão foram utilizados coletores do tipo covo espaçados pelo riacho, em diferentes estações climáticas do ano. A investigação de preferência de substrato foi conduzida com o uso de calhas de PVC cobertas por malha e dispostas no riacho para o experimento em condições de densidade controlada, e com surber, para busca ativa no riacho. A análise de área de vida foi realizada com a utilização da técnica de rádio telemetria. A população em questão foi estimada em 950 indivíduos na primavera e 210 indivíduos no outono (estimativas segundo o Método Bayesiano). Com relação à preferência de substrato, verificamos que há associação ontogenética quanto à escolha. Os juvenis, nos primeiros estágios de desenvolvimento, preferem substratos arenosos, enquanto que adultos (machos e fêmeas) preferem substratos mais complexos. Estimou-se também que a área de vida desses eglídeos varia desde 8,41 metros até, aproximadamente, 45,49 metros lineares de riacho, e que estes crustáceos apresentam comportamento de deslocamento local, já que realizam suas atividades em torno de um ponto específico do riacho. Observou-se ainda que os juvenis eglídeos, assim como os adultos, são caminhadores ativos, não sendo carregados pela correnteza de forma passiva como ocorre nas fases larvais de outros crustáceos. Suas atividades estão relacionadas com a temperatura do ambiente e com a densidade de adultos machos no riacho. Acreditamos que muito se avançou em termos de conhecimento da ecologia do grupo como um todo, e não apenas para a espécie estudada, servindo este estudo de base para estudo futuros sobre dispersão e área de vida principalmente.
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Den svarthuvade snigelns (Krynickillus melanocephalus) substratpreferens vid äggläggning / Krynickillus melanocephalus substrate preference during ovipositionBrodén, Geir January 2023 (has links)
Krynickillus melanocephalus was first seen in Sweden 2015. It is now labeled as an invasive species and it potentially poses a threat to the ecosystem, but the slug has not yet shown to have great negative impact in gardens and agricultural fields. There is limited ecological knowledge about the species. This study aims to increase the knowledge about habitat preference of the species during oviposition. Fifty slugs were placed in experimental arenas containing four compartments, each containing a different substrate: birch leaves, gravel, potting soil and sphagnum moss. The position of the slugs were recorded daily for three consecutive days. Further, position of laid eggs were recorded at two different times. Slugs showed a preference for leaves at oviposition, and 88 % of the eggs were laid in this substrate, and the fewest eggs were laid in moss (0,6 %). The slugs were found the most in contact with the leaves. The result has expanded our knowledge about the species, which is important to develop ways to hinder and slow down its invasion. Future research about substrate preference in this species should focus on how humidity and temperature may affect the substrate preference, as well as on movement behaviour during oviposition, perhaps by means of PIT telemetry. The study provides practical advice regarding how to deal with garden waste in areas that are inhabited by the species, where, in particular birch leaf compost should not be moved around. / Den svarthuvade snigeln upptäcktes i Sverige först 2015. Nu är den klassad som eninvasiv art och blir ännu ett hot mot våra ekosystem. Den kan även utgöra ett hot motträdgårdsägare, men än så länge har snigeln inte observerats ha åstadkommit störreskada. Arten är relativt okänd och därav är litteraturen väldigt begränsad. Min studiesyftar därför till att öka den ekologiska kunskapen om arten. Preferens föräggläggningssubstrat undersöktes samt föredraget habitat underäggläggningsperioden. Femtio sniglar användes i studien och dessa placerades iexperimentarenor innehållande mindre plastkorgar med fyra olika substrat; björklöv,grus, blomjord och vitmossa. Sniglarnas position observerades vid tre tillfällen undertre dagar och i vilket substrat äggen placerats noterades vid två tillfällen. Sniglarvisade en tydlig preferens för löv som äggläggningssubstrat där proportionen lagdaägg var 0,88. Minst antal ägg fanns i mossan (0,6%). Sniglarna befann sig ocksåoftare i kontakt med lövsubstratet än de andra substraten. Resultatet har berikat vårkunskap om arten, kunskap som är viktig för att utveckla metoder för att bekämpadess spridning. Framtida viktiga studier om artens äggläggning kan inkluderabeskrivning av dess rörelsebeteende med hjälp PIT-telemetri, samt undersökningarom hur olika temperaturer och fukthalter påverkar substratpreferens. Min studie hargett insikt i praktiska implikationer om hur trädgårdsavfall bör hanteras i områdendär arten existerar, specifikt att komposter med björklöv inte bör flyttas runt.
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