Chrysococcus diaphanus is a loricate chrysophyte alga in the genus Chrysococcus, family Chromulinaceae. The epithet diaphanus (Greek/Latin: transparent or see-through) describes the delicate, translucent quality of the lorica that encloses the cell body. This silica-reinforced or organic covering is a diagnostic feature of the genus, encasing the photosynthetic protoplast while allowing the flagellum to project through an apical aperture. C. diaphanus is found in freshwater and brackish environments, with records from Scandinavian and northern European lakes and ponds. Chrysophytes of the loricate type are common in oligotrophic and subarctic freshwaters, where they form a regular component of the flagellated phytoplankton and nanoplankton communities. The genus Chrysococcus includes species that range from purely phototrophic to fully heterotrophic, with many displaying intermediate mixotrophic strategies depending on light availability and prey abundance. Loricated chrysophytes are also valuable in paleolimnology because the siliceous cysts and scales they produce are preserved in lake sediments for millennia, recording past environmental conditions. The species has not been formally assessed for conservation status and is listed as Not Evaluated by the IUCN.