02516nas a2200193   4500008004500000020001400045245010500059210006900164260002000233490000600253520180200259653009502061100002502156700001702181700002802198700002002226700002502246856005102271       2018                        Engldsh    a2296-774500aNovel ssDNA Viruses Detected in the Virome of Bleached, Habitat-Forming Kelp <i>Ecklonia radiata</i>0 aNovel ssDNA Viruses Detected in the Virome of Bleached HabitatFo  c2018-January-120 v43 aKelp forests provide essential habitats for organisms in temperate rocky shores. Loss of kelp forests has occurred over large areas in a number of temperate regions, including in Australia, where the dominant kelp Ecklonia radiata has been lost from substantial areas of the shoreline. Loss of E. radiata has been associated with environmental stressors, including increased temperature and anthropogenic contaminants, as well as biological factors, such as herbivory. Disease may also play a role, but there is little information on the role of disease in the loss of kelp from coastal ecosystems or on the potential role of pathogenic microorganisms, such as viruses. E. radiata across much of its distribution in Australia can develop a “bleached” phenotype, which may be a disease. To investigate whether the phenotype was associated with a potential viral agent, we shotgun sequenced viral particles that were isolated from kelp with normal (healthy) and bleached phenotypes. Each virome consisted of ~380,000 reads, of which ~25% were similar to known viruses. All samples were dominated by bacteriophages, but novel ssDNA virus sequences were detected that were almost exclusively in viromes from the bleached kelp phenotype. These ssDNA viruses are covered by 11 contigs that contained complete capsids and characteristic rep genes that were 30–60% similar to those of circular, Rep-encoding ssDNA viruses (CRESS-DNA viruses). CRESS-DNA viruses have not previously been described from macroalgae, and the rep genes were similar to CRESS-DNA viruses from marine water samples, snails, crabs, anemones, but also dragonflies. This raises the interesting possibility that the kelp could be a vector of the CRESS-DNA viruses to other organisms that are associated with the bleached state.10aCircovirus,microbial ecology,virome,Kelp,marine disease,Metagenome,CRESS-DNA,Viral Ecology1 aBeattie, Douglas, T.1 aLachnit, Tim1 aDinsdale, Elizabeth, A.1 aThomas, Torsten1 aSteinberg, Peter, D.  uhttps://algaldiseases.myspecies.info/node/172002555nas a2200169   4500008004500000020001400045245014100059210006900200260002100269490000600290520186200296653009602158100002802254700003202282700002002314856005102334       2016                        Engldsh    a1664-302X00aEffects of Temperature Stress and Aquarium Conditions on the Red Macroalga <i>Delisea pulchra</i> and its Associated Microbial Community0 aEffects of Temperature Stress and Aquarium Conditions on the Red  c2016-February-180 v73 aIn recent years, there has been an increase in the rate and severity of diseases affecting habitat-forming marine organisms, such as corals, sponges, and macroalgae. Delisea pulchra is a temperate red macroalga that suffers from a bleaching disease that is more frequent during summer, when seawater temperatures are elevated and the alga’s chemical defense is weakened. A bacterial cause for the disease is implied by previous studies showing that some isolated strains can cause bleaching in vitro and that host-associated microbial communities are distinct between diseased and healthy individuals. However, nothing is known about the successional events in the microbial community that occur during the development of the disease. To study this aspect in the future, we aimed here to develop an experimental setup to study the bleaching disease in a controllable aquarium environment. Application of a temperature stress (up to 27°C) did not cause a clear and consistent pattern of bleaching, suggesting that temperature alone might not be the only or main factor to cause the disease. The results also showed that the aquarium conditions alone are sufficient to produce bleaching symptoms. Microbial community analysis based on 16S rRNA gene fingerprinting and sequencing showed significant changes after 15 days in the aquarium, indicating that the native microbial associates of D. pulchra are not stably maintained. Microbial taxa that were enriched in the aquarium-held D. pulchra thalli, however, did not match on a taxonomic level those that have been found to be enriched in natural bleaching events. Together our observations indicate that environmental factors, other than the ones investigated here, might drive the bleaching disease in D. pulchra and that the aquarium conditions have substantial impact on the alga-associated microbiome.10aBleaching,microbial shifts,microbial disease,holobiont,Environmental stressor,16S rRNA gene1 aZozaya-Valdés, Enrique1 aRoth-Schulze, Alexandra, J.1 aThomas, Torsten  uhttps://algaldiseases.myspecies.info/node/1656