The genus Afrocymbella (Bacillariophyceae) from lakes Malawi and Tanganyika, with description of new fossil and extant species

Abstract

Observations from modern communities and fossil diatom assemblages from Lake Tanganyika and Lake Malawi were analyzed to explore species richness in the genus Afrocymbella. Modern samples were collected along the shores of both lakes and from open water sites. Fossil assemblages were analyzed from two existing cores collected near the central basins of both lakes, spanning back to the late Pleistocene. We document seven previously described Afrocymbella species, namely A. muellerii, A. beccarii, A. brunii, A. gracilis, A. kociolekii, A. rossii, and A. tanganyikae. We also encountered five Afrocymbella species (A. symmetrica sp. nov., A. nyassae sp. nov., A. delphinea sp. nov., A. cocquytiana sp. nov., and A. gibba sp. nov.) in both modern samples and fossil assemblages that did not fit any existing species and are here described as new to science.