The Kalkalpen National Park is situated in Upper Austria and contains more than 800 springs. The international importance of this Park is, from the perspective of nature conservation directives, highly significant (European Nature Reserve Natura 2000, recognised wetland of the Ramsar convention). In the current study, the hydrobioid fauna (‘spring snails’) of the Kalkalpen National Park was evaluated. These tiny snails are difficult to determine; however, their investigation is especially desirable, as several species are threatened and as they are important for water quality assessment. Snails collected in 39 selected springs were examined with classical morphological methods (shell and genital anatomy) and, subsequently, by DNA analysis. For this task, the DNA barcode, a partial sequence of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene (length of the sequence 658-682 bp), was PCR amplified and sequenced. From 107 specimens, the DNA barcoding sequence could be obtained and compared with already existing DNA sequences. The (sub)endemic species Bythinella conica, Hauffenia kerschneri, Hauffenia wienerwaldensis and Belgrandiella aulaei could be clearly identified. For Bythiospeum nocki, despite the ambitious collecting effort, only empty shells were found in four springs (including the locus typicus spring) in the Park and its surroundings. The genus Bythinella was detected in 36 springs. From 25 of these localities, DNA barcodes could be created, which matches those of Bythinella conica (comparison data from ABOL). It is, therefore, concluded that the species occurs widely in the Kalkalpen National Park. The genus Hauffenia was sampled from 16 springs. From one, the haplotype of Hauffenia wienerwaldensis could be identified (spring is 5 km outside the Park) and from six, the haplotype of Hauffenia kerschneri. Belgrandiella aulaei was found in three springs, which all lie outside the boundaries and are, therefore, not included in the protection measures of the National Park. The data and analyses obtained contribute to the assessment of the taxonomic status of the species studied. The present study gives a good baseline for further monitoring of the hydrobioids in the Kalkalpen National Park, which is important to evaluate current as well as to decide on future protection measures for this group.
