Quadrigula is a genus of green algae in the family Selenastraceae.See the NCBI webpage on Quadrigula. Data extracted from the It is commonly found in freshwater habitats as phytoplankton.
Description Quadrigula forms colonies of two, four, or cells within a common mucilaginous envelope. Cells are cigar-shaped, 7 to 45 μm long and 1 to 8 μm wide. The cells are bundled such that the long axes of cells are parallel to each other. The tips of the cells are rounded or acutely pointed. Cells contain a single nucleus and one parietal chloroplast; the chloroplast may or may not contain a pyrenoid.
Species identification relies on details of the cell size and shape.
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