Chrysosphaerella triangulata is a colonial freshwater chrysophyte microalga in the genus Chrysosphaerella, class Chrysophyceae, order Chromulinales. Chrysosphaerella species form spherical free-floating colonies of golden-brown cells embedded in a gelatinous matrix, with individual cells bearing elongated siliceous scales that project outward from the colony surface. The species epithet triangulata — triangular — refers to the triangular cross-section or profile of the siliceous scales on the cell surface, which distinguishes this species from C. annulata, which has annular ring structures on its scales, and from other congeners with different scale geometries. Siliceous scale morphology examined under scanning electron microscopy is the primary diagnostic character for Chrysosphaerella species identification. C. triangulata has been recorded from Norwegian and Swedish freshwater habitats, part of the documented chrysophyte flora of boreal and subarctic Scandinavian lakes. These environments are characterized by cold, clear, nutrient-poor water and seasonal ice cover, creating conditions favorable for chrysophyte diversity including colonial forms like Chrysosphaerella. The colonies inhabit the photic zone of the water column, photosynthesizing with chlorophylls a and c and carotenoid accessory pigments. Chrysosphaerella scales deposited in lake sediments serve as paleolimnological indicators. C. triangulata has not been formally evaluated under IUCN criteria and is listed as Not Evaluated. It contributes to documentation of the rich chrysophyte diversity in Scandinavian freshwater systems.