Eukaryotic picoplankton, Mychonastes homosphaera (Chlorophyceae, Chlorophyta), in Lake Kinneret, Israel

SUMMARY Eukaryotic picoplankton was isolated from Lake Kinneret, Israel. This green picoplankton is spheroidal or ovoidal in shape. The cell wall has a network of ribs on its surface. The chloroplast is cup- or mantel-shaped without a pyrenoid. The morphology and cellular structure of this autosporic alga is identical with Mychonastes homosphaera (Skuja) Kalina et Puncochařova. The phylogenetic tree based on 18S ribo-somal RNA gene sequence data showed that M. homosphaera is placed in the Chlorophyceae and located at the base of a branch leading to the other algae possessing directly opposed orientation of the flagellar apparatus.