Glöer, P. (2022): The freshwater Gastropods of the West-Palaearctis. Volume 2

Glöer, P. (2022): The freshwater Gastropods of the West-Palaearctis. Volume 2. Moitessieriidae, Bythinellidae, Stenothyridae. Identification key, anatomy, ecology, distribution. 523 Taf. mit über 1600 Einzelfotos, 793 Lit., Taxaverz.- 386 pp., (Selbstverlag) Hetlingen. Geb.

The second volume of the work deals with 3 families with 23 genera and 464 species. The most species-rich genera, By­thiospeum with 106 species and Bythinella with 288 species, are also represented in Germany and Central Europe. The vast majority of species are only known from the locus typicus, this extreme endemism is explained by the spe­cificity of their habitats: All species of the 3 families live in springs and/or in subterranean waters, they are obligate crenobionts or stygobionts. The possibility of dispersal for species from such isolated habitats and with the life form of a freshwater snail is low; added to this is the denaturation of land used for agriculture today, which rein­forces the isolation. As a result, all these species are highly endangered. Due to the circumstances described above, the descriptions and photos are mainly based on the type material. When identifying the species, an essential characteristic is the place of discovery. As far as identification keys could be compiled, they are structured according to countries or groups of countries. For the genera Bythiospeum and Bythinella no identification keys are offered. Here, tables with all species of the country concerned in alphabetical order and overview maps with the (often only) finding localities are helpful.

Layout, type-setting, printing and book cover and all marks of quality are the same as in volume 1.