Synura

Synura is a genus of freshwater, colonial golden algae (Chrysophyceae). These algae are characterized by their spherical or ovoid colonies composed of individual, flagellated cells. Each cell within the colony is typically covered with silica scales, called scales or plates, that contribute to the overall structure and appearance of the colony. These scales are often ornamented with intricate patterns and are useful in species identification.

Synura colonies are motile, propelled through the water by the coordinated beating of the flagella of individual cells. Colony size can vary, ranging from a few cells to hundreds of cells. Synura is found globally in freshwater environments, including lakes, ponds, and reservoirs.

Blooms of Synura can occur under favorable environmental conditions, such as nutrient enrichment and suitable temperature. These blooms can impart an unpleasant odor and taste to the water, often described as fishy, cucumber-like, or oily. This can pose problems for drinking water supplies and recreational water use. Taste and odor compounds produced by Synura, such as aldehydes, can be difficult to remove from water.

Taxonomically, Synura is placed within the class Chrysophyceae and is closely related to other colonial golden algae. The exact number of Synura species is debated, and classification can be challenging due to variations in scale morphology and genetic differences. Microscopic examination of the silica scales is essential for species identification, often requiring electron microscopy for detailed analysis. The genus is actively studied for its ecological role and its impact on water quality.