Synurid

The synurids (order Synurales) are a small group of heterokont algae, found mostly in freshwater environments, characterized by cells covered in silica scales.

==Characteristics== thumb|right|upright|alt=High magnification SEM image of a single Synura cell: It is covered with about 50 delicate, oval scales.|A single cell of the freshwater algae species Synura petersenii, false color image created using Scanning electron microscope|SEM They are covered in silicate scales and spines. In Synura, these are formed on the surface of the chloroplasts, two of which are usually present, but sometimes only one divided into two lobes is seen. The cells have two heterokont flagella, inserted parallel to one another at the anterior, whose ultrastructure is a distinguishing characteristic of the group. Both asexual and isogamous sexual reproduction occur.