Bonn River strew, Steve Edgar

Bonn River strew, 10x Nikon Plan Apo NA 0.45 objective
Navicula lewisiana
Coscinodiscus sp.?
Actinoptychus vulgaris

A strew slide from Bonn River, West Africa. Wide range of species present, including Navicula lewisiana, Actinoptychus sp. and Coscinodiscus sp.. Prepared by Steve Edgar. Part of the Meakin Collection 2005. Mounted in Pleurax. Olympus BHB microscope using 450nm LED light. Main stacks using a 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Stacks prepared in Zerene (Pmax).

As a side note, I’m not sure where the ‘Bonn River’ is in West Africa. Meakin’s notes for sample 726 also say Bonn River. There is a Benue river, which is a major tributary of the Niger River. There is also the Bandama River, which runs all the way to the coast. The WoRMS diatom database lists N. lewisiana as living in ‘brackish water’, perhaps pointing towards the tidal lagoon of the Bandama River as a source for this sample, although this is just speculation on my behalf.