Cylindrospermopsis

Cylindrospermopsis is a genus of filamentous freshwater cyanobacteria in the order Nostocales. The best-known species is Cylindrospermopsis raciborskii, a bloom-forming organism that has been reported in warm-water lakes, reservoirs, and rivers around the world. The genus is characterized by cylindrical cells arranged in trichomes, often surrounded by a gelatinous sheath; some strains possess heterocysts for nitrogen fixation.

Morphology and physiology vary among species, but members are typically light-requiring and capable of forming dense surface blooms under favorable conditions. Blooms are commonly associated with stable stratification, higher temperatures, and nutrient-rich waters, and they can persist as surface scums or clumps that reduce water quality and oxygen levels.

Distribution and ecology: Cylindrospermopsis is most prominent in tropical and subtropical regions but has spread into temperate zones in recent decades. It can be transported by water currents or anthropogenic means and may become established in new habitats, especially where climate and nutrient conditions favor growth.

Toxins and health concerns: Many Cylindrospermopsis strains produce cylindrospermopsin, a hepatotoxin and cytotoxin that can contaminate drinking water and aquatic food webs. Toxin levels vary with strain and environmental conditions, and exposure can pose risks to humans and animals. Some reports note the presence of additional toxins in certain strains, but cylindrospermopsin remains the primary concern associated with the genus.

Management and monitoring: Water managers monitor for cyanobacterial blooms and cylindrospermopsin during high-risk periods. Prevention focuses on reducing nutrient inputs and limiting growth, while treatment may involve advanced oxidation or other water-treatment methods to remove toxins from drinking water.