09. April 2008 · Press release

More Micrasterias images

Photos of the press release "Alga of the Year 2009: Micrasterias - immortal but in the Red Data Book for endangered species

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Use of the images is only permitted in connection with reporting on the topic ‘alga of the year 2015’ and only if the photographers are acknowledged in the format: first name, second name, institution. Commercial use of the images is not permitted.

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Micrasterias ceratofera is a spiky exotic species from south-east Asia, first described in 1985. The species lives on the bottom of tropical water bodies such as lakes and rivers, and sometimes free-floating as plankton. In contrast to most of the Micrasterias species that occur in Germany, Micrasterias ceratofera does not inhabit boggy places and its distribution in the tropics does not appear to be threatened. The alga on this image was originally collected from Indonesia in 1983. It was brought back to Germany and has been growing in culture ever since. This culture is available for scientific research in the "Sammlung von Conjugaten-Kulturen (SVCK; Culture Collection for Conjugate Algae)’ at the Institut für Allgemeine Botanik at the University of Hamburg. Image: Dr. Monika Engels, desmid algal collection, University of Hamburg
A transparent nucleus is visible in the centre of the disc-shaped species Micrasterias radiosa which typically inhabits upland bogs. Also clearly visible are the numerous small round vesicles that store starch (pyrenoids). The species is very rare in Germany and classified as ‘endangered’ because it can not survive in water bodies affected by nutrient-loading. (Image: Dr. Monika Engels, desmid algal collection, University of Hamburg)
Micrasterias crux-melitensis was first described from the environs of Berlin in the 1830s.The habitats where it was previously found are now part of Inner City Berlin and have lost their value for the potential growth of desmids. The alga has disappeared even from the outskirts of Berlin since the 1930s. It appears to be still more common in the Netherlands. Image: Dr. Monika Engels, desmid algal collection, University of Hamburg
Micrasterias truncata is considered an endangered species in Germany according to the Red Data Book. Its distribution is limited mostly to nutrient-poor, oligotrophic to mesotrophic bogs. It occurs more commonly in the subalpine regions of Germany and the Austrian Alps. In this image the two green chloroplasts located in the two compartments of the cell are visibly lobed. Image: Dr. Monika Engels, desmid algal collection, University of Hamburg