Synura, spring is in the air!

Synura sp. Chrysophytes or Golden Algae, are common in freshwater habitats especially in spring. These motile spherical colonies have yellow brown plastids, two flagella of different length and are covered with siliceous scales. 

Golden colonial algae

The term colonial as used here applies to algae composed of free-swimming look alike unicells, which form groups that may be large and elaborately interconnected as in Volvox, or smaller and relatively simple as in Synura.

The Synura colonies shown in this video - taken in phase contrast - have ovoid golden-brown cells characteristic of the Chrysophyta, each cell bearing two flagella whose beating propels the colony through the water with a smooth rolling motion.