[2] In the population first described, there are two ribs running along the length of the shell; hence the scientific name bicarinata ("two-keeled").

In 1996 it was classified as Critically Endangered (A1ce) by the IUCN, as its habitat – essentially the Fontaine de la Vierge and nearby springs in the Dordogne[2] – was being affected by pollution and the local snail populations had declined more than 80% in the late 20th century.

[1] However, analysis of mtDNA COI and nDNA ITS1 sequence data showed that the "typical" two-keeled Bythinella bicarinata are actually part of a clade widespread in central to northeastern France and nearby regions.

The populations from Belgium and western Germany described as Bythinella dunkeri were in 1996 classified as Vulnerable (B1+2c), as they were known from less than ten freshwater springs which are affected by pollution.

[3] Given that they occur at the other end of the species' range and are consistently most distinct morphologically from the "keeled" specimens, they might also warrant recognition as subspecies.