Synurid algae. Polarised light micrograph of Synura uvella algae colonies (round) next to the body of a dead copepod crustacean (lower right). Synurids are a small group of golden-brown algae, found mostly in freshwater. They are covered in silicate scales and spines and occur as spherical colonies (as here). Several scale types occur on the same cell, depending on their position in the colony. Magnification: x100, when printed 10 centimetres wide.