Stimpson (1865) described the genus as follows: “Shell ovate-conic, imperforate; apex acute; whorls coronated with spines; outer whorl nearly two-thirds the length of the shell; aperture ovate, outer lip acute. Operculum corneous, subspiral. Foot rather short for the length of the shell, broadest in front and strongly auriculated. Tentacles very long, slender, and tapering. Eyes on very prominent tubercles. Rostrum of moderate size.”
However, one species within this genus, P. antipodarum, has been accidentally introduced in many countries worldwide, especially in Europe and North America, and has become a problematic invasive species.
Criscione, F. and W.F. Ponder. 2013. A phylogenetic analysis of rissooidean and cingulopsoidea families (Gastropoda: Caenogastropoda). Molecular Phylogenetics and Evolution 66(3):1075-1082.
Stimson, W. 1865. Diagnoses of newly discovered genera of Gasteropods, belonging to the sub-fam. Hydrobiinae, of the family Rissoidae. American Journal of Conchology 1:52-54.
Vaught, K.C. (1989). A classification of the living Mollusca. American Malacologists: Melbourne, FL (USA). ISBN0-915826-22-4. XII, 195 pp
Winterbourn, M. 1970. The New Zealand species of Potamopyrgus (Gastropoda, Hydrobiidae). Malacalogia 10(2):283-321