Spring Snails, Mud Snails, Bithynias and their Relatives (Truncatelloidea)

Bythinella cylindrica, Family Bythinellidae. Picture: © Alexander Mrkvicka, Vienna.

Belgrandiella wawrai, Family Hydrobiidae. Picture: © Alexander Mrkvicka, Vienna.

Systematik der Truncatelloidea
Caenogastropoda > Littorinimorpha > Truncatelloidea

Superfamily Truncatelloidea

Family Hydrobiidae
Unterfamilie Belgrandiellinae
Belgrandiella
Graziana
Unterfamilie Horatiinae
Sadleriana
Unterfamilie Hydrobiinae
Peringia (Mudflat snails)
Unterfamilie Pyrgulinae
Pyrgula

Family Bythinellidae
Bythinella

Family Moitessieridae
Bythiospeum

Family Amnicolidae
Marstoniopsis

Family Lithoglyphidae
Lithoglyphus

Family Tateidae
Potamopyrgus

Family Emmericiidae
Emmericia

Family Bithyniidae
Bithynia

Source: WoRMS: MolluscaBase eds. (2025): Truncatelloidea J.E. GRAY, 1840.

For the sake of simplicity, the large number of small to minute freshwater and brackish water snails are often referred to collectively as spring snails. In reality, however, they belong to a broader superfamily: the Truncatelloidea.

According to the latest classification used in the WoRMS database, the system displayed on the right is currently applied.

Recent molecular studies (Wilke et al., 2001) have shown that spring snails in the strict sense, such as the genus Bythinella, do not in fact belong to the Hydrobiidae, but rather to a separate family within the Rissooidea: the Amnicolidae.

In contrast, the Hydrobiidae do include various groups of spring-dwelling snails, such as Belgrandiella pareyssii, the thermal spring snail, which shares its habitat in warm springs (e.g. in Bad Vöslau, Lower Austria) with the thermal nerite (Theodoxus prevostianus) and the thermal river snail (Esperiana daudebartii).

Not a member of the Hydrobiidae is the well-known New Zealand mud snail (Potamopyrgus antipodarum), an invasive species introduced to many parts of the world. It is assigned to a separate family, the Tateidae.

Another distinct family within the Truncatelloidea are the Lithoglyphidae (gravel snails), represented in Central Europe by the river pebble or gravel snail (Lithoglyphus naticoides).

Also part of the Truncatelloidea is the family Bithyniidae, or faucet snails, such as Bithynia tentaculata.

The table on the right is intended to help users navigate and orient themselves among the various species pages.

Literature:

Bouchet, P.; Rocroi, J.-P.; Frýda, J.; Hausdorf, B.; Ponder, W.; Valdés, Á. u. Warén, A. (2005). "Classification and nomenclator of gastropod families". Malacologia 47 (1 - 2): 1 – 397.
Wilke, T.; Davis, G. M.; Falniowski, A.; Giusti, F.; Bodon, M. u. Szarowska, M. (2001). "Molecular systematics of Hydrobiidae (Mollusca: Gastropoda: Rissooidea): testing monophyly and phylogenetic relationships". Proceedings of the Academy of Natural Sciences of Philadelphia 151 (1): 1 – 21.
WoRMS: MolluscaBase eds. (2025): Truncatelloidea J.E. GRAY, 1840.