Diatom of the month - March 2018: Afrocymbella barkeri
by Heather Moorhouse* The tropical diatom genus Afrocymbella has only 12 known species, all of which are found in the African Rift Valley lakes 1 . They have been observed both free-living in the water column and attached to rocks and plants, and are solitary or colonial 1 . One such species is Afrocymbella barkeri Cocquyt & Ryken sp. nov. (19.9-63.8 µm) (Fig. 1), a newly described diatom found in Lake Chala 1 (Fig. 2) , a tropical crater lake that lies directly on the border of Kenya and Tanzania , just south of the equator (Fig. 3) . This species was named after Prof. Philip Barker whose seminal work on diatoms in the East African Rift valley lakes has helped understand past climate and environmental change in the region. Afrocymbella barkeri is common at the end of the dry and windy season in Lake Chala, which corresponds to the northern hemisphere summer. The summer winds mix the lake water column and cause nutrient-rich deep water to rise to t...