The spirogyra is a multicellular organism. For those who are not familiar with this, this is a type of green algae that you will find in various tropical areas of the world. Take note that this is found in freshwater and not saltwater. There are actually 400 species of algae that can be found right now.
The fact that this is multicellular means that it is composed of many different cells. They are microscopic, which means that the cell partitions may not immediately become visible. They are not as complex as compared to the cells of more developed organisms, but they are still composed of more than one cell.