Chroomonas acuta is a species of cryptophyte alga in the family Chroomonadaceae, found in freshwater and brackish aquatic environments. Cryptophytes are biflagellate, unicellular algae characterized by the presence of a unique organelle called the nucleomorph — a remnant nucleus from a secondary endosymbiotic event in which an ancestral flagellate engulfed a red alga. This evolutionary heritage is reflected in the distinctive combination of pigments in the plastid, including chlorophyll a, chlorophyll c, and phycobiliproteins such as phycoerythrin and phycocyanin, which give cryptophytes their often blue-green to red-brown color. Chroomonas species are small flagellates that swim using two unequal flagella arising from a ventral groove. They are important members of freshwater phytoplankton communities, particularly in the cold-water picoplankton. Chroomonas acuta has a more pointed or acute cell shape compared to some related species, as indicated by its epithet. The species has been documented from European freshwater habitats. Cryptophytes contribute to primary production in freshwater and marine ecosystems and are a significant food source for heterotrophic protists and filter-feeding zooplankton. The species has not been assessed by the IUCN.