Spirogyra reproduce using sexual or asexual reproduction methods. The process of reproduction varies depending on species of spirogyra; in vegetative varieties, reproduction occurs through the process of fragmentation, which involves the transformation of spirogyra through intercalary mitosis to produce new filaments.
Spirogyra occur primarily as green algae and live predominantly in watery environments such as rivers, lakes and freshwater bays. They thrive in freshwater habitats and vary widely in size and appearance. Spirogyra species also vary in physical composition, which determines how they reproduce. Some spirogyra contain both male and female reproductive organs, enabling them to reproduce asexually. However, others reproduce sexually, which occurs in several ways. One method of sexual reproduction is that of scalariform conjugation. This process requires two different filaments to line up beside each other. One cell from each filament then emits tubular protuberances, called conjugation tubes, which extend and couple. This creates a passage called the conjugation canal, which enables the exchange of male and female reproductive components. In lateral conjugation, gametes form in a single filament. Two proximate cells near the transverse walls of the filament extend conjugation tubes, which form a canal upon coupling. The male cytoplasm then journeys through the conjugation canal and ultimately fuses with the female cytoplasm to enable fertilization to take place.