Historical diatom material from the East African Great Lakes

Algae material from the African Great Lakes was for the first time sampled during the Livingstone mission (1861-1863) at the shores of Lake Malawi; the findings were published by Dickie in 1879. We had to wait for more than forty years, during the Third Tanganyika expedition conducted by Dr Cunnington (1904-1905), for a sampling in Lake Tanganyika. The results on the planktonic freshwater algae were published by G.S. West (1907) followed in 1954 by the overview work of Van Meel as a result of the ’l’exploration hydrobiologique du lac Tanganika (1946-1947)”. Among further important scientific missions to the region we must mention the German “Nyassa-See- und Kinga-Gebirgs-Expedition (1897-1898)”. Material collected by Fülleborn and assumed to be lost during WWII was discovered in the Botanical Museum Berlin-Dahlem in the 1990’s. It concerned samples belonging to the material from which Otto Müller (1903, 1904, 1905, 1910) described over 100 new East African diatom taxa. Re-investigation of this material is needed not only to make Müller’s taxa described in German more accessible to the scientific community but also to evaluate possible new or endemic species and to solve taxonomic problems that have arisen since the renewed attention to African diatoms. As the original slides were destroyed, new permanent diatom slides had to be made and lectotypificiation to be done. The presence of unmounted original material has the advantage that in-depth investigation of the taxa by scanning electron microscopy can be conducted. Taxa described by Müller from the genera Iconella, Surirella, Cymatopleura and Rhopalodia, (Cocquyt & Jahn 2005, 2007a, b, c, d, 2014, 2018, Jahn et al. 2017) have been the subject of such re-investigations already.

Jaar van publicatie:2018