Morphology and taxonomic assessment of eight genetic clades of Mercuria Boeters, 1971 (Caenogastropoda, Hydrobiidae), with the description of five new species

  • Jonathan P. Miller Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
  • Diana Delicado Justus Liebig University Giessen, Department of Animal Ecology & Systematics, Heinrich-Buff-Ring 26-32 IFZD, 35392 Giessen, Germany
  • Fernando García-Guerrero Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
  • Noureddine Khalloufi University of Carthage, Faculty of Sciences of Bizerte, LR01ES14 Environmental Biomonitoring Laboratory, 7021 Jarzouna, Tunisia
  • Marian A. Ramos Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
Keywords: taxonomy, phylogeny, freshwater gastropods, Mediterranean region, geometric morphometrics


The freshwater snail genus Mercuria is widely distributed in lowland waters across Western Europe, Northern Africa and the Mediterranean islands. Approximately two-thirds of the currently recognised species are described based on their shell morphology, which may vary within species due to biotic and abiotic factors. Recent molecular phylogenies that included numerous previously documented populations recovered 14 species clades, nine of which correspond to nominal species and five, to undescribed taxa. Here, we formally describe the five undescribed taxa as new species and provide morphological descriptions of the shell and other anatomical structures for three of the other inferred clades and for the species M. maceana to elucidate their taxonomic status and assess the utility of morphological characters for species delimitation in Mercuria. Taken together, the morphological and molecular evidence suggest new identifications and synonymies, having implications on the known geographic range of the studied species, including the type species M. similis. Anatomical measurements and geometric morphometric analysis of shell shape revealed no clear differentiation among the species analysed, predicting the importance of molecular data in elucidating the species diversity of the genus.


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How to Cite
Miller, J. P., Delicado, D., García-Guerrero, F., Khalloufi, N., & Ramos, M. A. (2023). Morphology and taxonomic assessment of eight genetic clades of Mercuria Boeters, 1971 (Caenogastropoda, Hydrobiidae), with the description of five new species. European Journal of Taxonomy, 866(1), 1–63.