The Saprospiraceae, a family within the order Sphingobacteriales and the phylum Bacteroidetes, embrace the genera Saprospira, Lewinella, Haliscomenobacter, Aureispira, ‘‘Rubidimonas,’’ and ‘‘Portibacter.’’ The composition of the family, and delineation of genera and species, is largely defined by 16S rRNA gene phylogeny. Most are isolated from aquatic environments, predominantly marine associated but also freshwater and activated sludge. Isolates and in situ strains have a demonstrated ability for the hydrolysis and utilization of complex carbon sources, with the helical gliding strains also associated with predation of other bacteria and algae. Family members are likely important in the breakdown of complex organic compounds in the environment. Such a role is at least demonstrated in situ for activated sludge wastewater treatment systems where these organisms are frequently observed in abundance.